HTML Tutorial

HTML ------ 关于表单 Form - Tina_xy

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

May 22, 2016 pm 05:19 PM

Form(表单)主要用于采集和提交用户输入的信息，是页面与WEB服务器交互过程中最重要的信息来源。

掌握表单(Form)有以下几个要点：

重要form属性

form常用控件

form提交方式

§　　重要form属性

action {URL}：规定表单提交时向何处发送数据。

enctype ：规定在发送表单数据之前如何对表单数据进行编码。（值如下）

　　　　　　 application/x-www-form-urlencoded ：在发送前编码所有字符（默认为此方式）。

　　　　　 multipart/form-data ：不对字符编码。注：使用包含文件上传控件的表单时，必须使用该值。

method：指定表单以何种方法发送。

　　　　　　 get ：from表单里所填的值，附加在action指定的URL后面，做为URL链接而传递。（可以在地址栏看见表单的提交信息）

　　　　　　 post ：from表单里所填的值，附加在HTML Headers上。（不可以在地址栏看见表单的提交信息）

§　　form常用控件

标记：

　　标记为input元素定义标注，它的for 属性应当与相关元素的id属性相同。绑定后单击该文字，鼠标将聚焦到绑定的表单控件上。

　　　建议：每一个表单元素的文字描述都使用标记！（两标签之间的内容即为对绑定的表单控件的文字描述）

　　　注意：每个表单元素应当分配 name 属性和 id 属性。( name 属性和 id 属性应该尽可能地使用相同的或相关的值。)

　　　　　　name 属性：用来将数据提交到服务器；

　　　　　　id 属性：用来在客户端做相应的操作；如：标签的绑定、CSS 选择器的使用等。

文本输入框: 　　　　　　　　

1)、input type="text" 单行文本框

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">label  </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">= "Account"</span><span style="color: #0000ff;">></span>账号：<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">input  </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="Account"</span><span style="color: #ff0000;">  id</span><span style="color: #0000ff;">="Account"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="账户" maxlength="20"</span><span style="color: #0000ff;">></span></span></span></span>

2)、textarea 多行文本框

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="comment"</span><span style="color: #0000ff;">></span>评论：<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">textarea </span><span style="color: #ff0000;">name</span><span style="color: #0000ff;">="comment"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="comment"</span><span style="color: #ff0000;"> cols</span><span style="color: #0000ff;">="30"</span><span style="color: #ff0000;"> rows</span><span style="color: #0000ff;">="15" maxlength="100"</span><span style="color: #0000ff;">></span><span style="color: #800000;">textarea</span><span style="color: #0000ff;">></span></span></span></span>

说明: maxlength 规定文本区域的最大字符数；如果在中输入字符时，换行也算一个字符。

密码输入框：

　　定义密码字段。（字符会被遮盖）

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">label  </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">= "Password"</span><span style="color: #0000ff;">></span>密码：<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">input  </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="password"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="password"</span><span style="color: #ff0000;">  id</span><span style="color: #0000ff;">="password"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="密码"</span><span style="color: #0000ff;">></span></span></span></span>

单选框：

设置单选按钮以及获取选中的单选按钮的值

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">form </span><span style="color: #ff0000;">name</span><span style="color: #0000ff;">="MyForm"</span><span style="color: #ff0000;"> action</span><span style="color: #0000ff;">="URL"</span><span style="color: #ff0000;"> method</span><span style="color: #0000ff;">="post"</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span><span style="color: #000000;">性别：
　　　</span><span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="radio"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="sex"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="male"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="male"</span><span style="color: #0000ff;">><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="male"</span><span style="color: #0000ff;">></span>male<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
　　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="radio"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="sex"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="female"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="female"</span><span style="color: #0000ff;">><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="female"</span><span style="color: #0000ff;">></span>female<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="button"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="获取选中项"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="getValue();"</span> <span style="color: #0000ff;">/></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">form</span><span style="color: #0000ff;">><br><br></span><span style="color: #000000;">//获取选中的单选值
</span><span style="color: #0000ff;"><span style="color: #800000;">script </span><span style="color: #ff0000;">language</span><span style="color: #0000ff;">="javascript"</span><span style="color: #0000ff;">></span>
<span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> getValue(){
    </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">获取表单的所有提交信息（根据表单的name属性）</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;">  myform </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> document.forms[</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">MyForm</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">];
    </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">sex是单选按钮的name属性值</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> radioChoices </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> myform.sex;
    </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">遍历整个单选项表</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">for</span><span style="background-color: #f5f5f5; color: #000000;">(i</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">;i</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">radioChoices.length;i</span><span style="background-color: #f5f5f5; color: #000000;">++</span><span style="background-color: #f5f5f5; color: #000000;">)   
        </span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;">(radioChoices[i].checked)   
            </span><span style="background-color: #f5f5f5; color: #0000ff;">break</span><span style="background-color: #f5f5f5; color: #000000;">; </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">发现了被选中项,退出</span>
<span style="background-color: #f5f5f5; color: #000000;">    alert(</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">选中的选项是：</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">radioChoices[i].value);
}
</span><span style="color: #0000ff;"></span><span style="color: #800000;">script</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span>

注意：

1）、在客户端，Javascript 对表单及表单元素的操作，更常用其name 属性而不是id属性。因为，对于某些特定的表单元素(如：单选按钮等)，使用其name 属性更易于获得元素值，也更方便向服务器传送数据！

2）、保证同一组单选按钮的name 属性值相同。

复选框：

复选框的“全选”、“全不选”、“反选”功能以及所选复选框值的获得功能

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">form </span><span style="color: #ff0000;">name</span><span style="color: #0000ff;">="MyForm"</span><span style="color: #ff0000;"> action</span><span style="color: #0000ff;">="URL"</span><span style="color: #ff0000;"> method</span><span style="color: #0000ff;">="post"</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="checkbox"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="hoboy"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="music"</span><span style="color: #0000ff;">><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="music"</span><span style="color: #0000ff;">></span>music<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="checkbox"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="hoboy"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="swim"</span><span style="color: #0000ff;">><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="swim"</span><span style="color: #0000ff;">></span>swim<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">　　<span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="checkbox"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="hoboy"</span><span style="color: #ff0000;"> id</span><span style="color: #0000ff;">="dance"</span><span style="color: #0000ff;">><span style="color: #800000;">label </span><span style="color: #ff0000;">for</span><span style="color: #0000ff;">="dance"</span><span style="color: #0000ff;">></span>dance<span style="color: #0000ff;"></span><span style="color: #800000;">label</span><span style="color: #0000ff;">></span>

　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="button"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="全选"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="selectBoxs(1);"</span> <span style="color: #0000ff;">/></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="button"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="全不选"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="selectBoxs(0);"</span> <span style="color: #0000ff;">/></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="button"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="反选"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="selectBoxs(-1);"</span> <span style="color: #0000ff;">/></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="submit"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="提交"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="submit();"</span> <span style="color: #0000ff;">/></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">form</span><span style="color: #0000ff;">></span>

<span style="color: #0000ff;"><span style="color: #800000;">script </span><span style="color: #ff0000;">language</span><span style="color: #0000ff;">="javascript"</span><span style="color: #0000ff;">></span>

<span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">全选，全部选，反选</span>
<span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> selectBoxs(value){
    </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> myform </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> document.forms[</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">MyForm</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">];
    </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">hoboy 为所有复选框的name属性值</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> CheckboxChoices </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> myform.hoboy;
 
    </span><span style="background-color: #f5f5f5; color: #0000ff;">for</span><span style="background-color: #f5f5f5; color: #000000;">(</span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> i</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">;i</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">CheckboxChoices.length;i</span><span style="background-color: #f5f5f5; color: #000000;">++</span><span style="background-color: #f5f5f5; color: #000000;">)    </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">遍历每一个选项</span>
        <span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;">(value </span><span style="background-color: #f5f5f5; color: #000000;"> <span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">)</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">反选</span>
<span style="background-color: #f5f5f5; color: #000000;">            CheckboxChoices[i].checked </span><span style="background-color: #f5f5f5; color: #000000;">=</span> <span style="background-color: #f5f5f5; color: #000000;">!</span><span style="background-color: #f5f5f5; color: #000000;">CheckboxChoices[i].checked;
        </span><span style="background-color: #f5f5f5; color: #0000ff;">else</span> 
            <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">value为1是则全选,为0时则全不选</span>
<span style="background-color: #f5f5f5; color: #000000;">            CheckboxChoices[i].checked </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> value;
}
    
</span><span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> getSelect(){
    </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> myform </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> document.forms[</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">MyForm</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">];
    </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> CheckboxChoices </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> myform.hoboy;
　　</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">创建数组放checkbox选中的值</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> arrayCheckbox </span><span style="background-color: #f5f5f5; color: #000000;">=</span> <span style="background-color: #f5f5f5; color: #0000ff;">new</span><span style="background-color: #f5f5f5; color: #000000;"> Array();
    </span><span style="background-color: #f5f5f5; color: #0000ff;">for</span><span style="background-color: #f5f5f5; color: #000000;">(</span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> i</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">;i</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">CheckboxChoices.length;i</span><span style="background-color: #f5f5f5; color: #000000;">++</span><span style="background-color: #f5f5f5; color: #000000;">){
    　　</span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;">(CheckboxChoices[i].checked)
    　　　　arrayCheckbox.push(CheckboxChoices[i].value);
    }
    alert(arrayCheckbox);
}

</span><span style="color: #0000ff;"></span><span style="color: #800000;">script</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

注意：保证同一组复选框按钮的name 属性值相同。

下拉框：

下拉框的重要属性：

multiple 属性:用于设置下拉表框的类型（多选还是单选）

type 属性：JS根据type 属性的值获得下拉列表框select 控件的类型。

type 属性的值为：select-multiple（多选）或 select-one（单选）

下拉列表框默认只能选中一项，若要设置为可以多选，则设置

size属性：定义可见选项的数目。size="3",即下拉框内可以显示三个可选选项。

<span style="font-size: 15px;"><span style="color: #0000ff;"><span style="color: #800000;">form </span><span style="color: #ff0000;">name</span><span style="color: #0000ff;">="MyForm"</span><span style="color: #ff0000;"> action</span><span style="color: #0000ff;">="URL"</span><span style="color: #ff0000;"> method</span><span style="color: #0000ff;">="post"</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>简单的选择列表<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">select </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="myselect"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="myselect"</span><span style="color: #ff0000;"> multiple</span><span style="color: #0000ff;">="multiple"</span><span style="color: #ff0000;"> size</span><span style="color: #0000ff;">="3"</span><span style="color: #0000ff;">></span>
       <span style="color: #0000ff;"><span style="color: #800000;">option </span><span style="color: #ff0000;">value</span><span style="color: #0000ff;">="Apples"</span><span style="color: #0000ff;">></span>Apples<span style="color: #0000ff;"></span><span style="color: #800000;">option</span><span style="color: #0000ff;">></span>
       <span style="color: #0000ff;"><span style="color: #800000;">option </span><span style="color: #ff0000;">value</span><span style="color: #0000ff;">="Bananas"</span><span style="color: #0000ff;">></span>Bananas<span style="color: #0000ff;"></span><span style="color: #800000;">option</span><span style="color: #0000ff;">></span>
       <span style="color: #0000ff;"><span style="color: #800000;">option </span><span style="color: #ff0000;">value</span><span style="color: #0000ff;">="Cherries"</span><span style="color: #0000ff;">></span>Cherries<span style="color: #0000ff;"></span><span style="color: #800000;">option</span><span style="color: #0000ff;">></span>
       <span style="color: #0000ff;"><span style="color: #800000;">option </span><span style="color: #ff0000;">value</span><span style="color: #0000ff;">="oranges"</span><span style="color: #0000ff;">></span>oranges<span style="color: #0000ff;"></span><span style="color: #800000;">option</span><span style="color: #0000ff;">></span>
   <span style="color: #0000ff;"></span><span style="color: #800000;">select</span><span style="color: #0000ff;">></span><span style="color: #800000;">br</span><span style="color: #0000ff;">></span>
　　<span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="button"</span><span style="color: #ff0000;"> onclick</span><span style="color: #0000ff;">="getSelectValue('myselect')"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="查看选项"</span> <span style="color: #0000ff;">/></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">form</span><span style="color: #0000ff;">><br><br></span><span style="color: #0000ff;"><span style="color: #800000;">script </span><span style="color: #ff0000;">language</span><span style="color: #0000ff;">="javascript"</span><span style="color: #0000ff;">></span>
    <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">获取选中的下拉列表值</span>
    <span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> getSelectValue(myselect){
        </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> myform </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> document.forms[</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">MyForm</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">];
        </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> select </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> myform.elements[myselect];
        </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">判断是单选还是多选</span>
        <span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;">(select.type </span><span style="background-color: #f5f5f5; color: #000000;">==</span> <span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">selece-one</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">){
            </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> oneChoice </span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;"> select.selectedIndex;</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">获取选中项</span>
<span style="background-color: #f5f5f5; color: #000000;">            alert(</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">单选</span><span style="background-color: #f5f5f5; color: #000000;">"</span> <span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;"> select.options[oneChoice].value);</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">获取选中项的值</span>
<span style="background-color: #f5f5f5; color: #000000;">        }
        </span><span style="background-color: #f5f5f5; color: #0000ff;">else</span><span style="background-color: #f5f5f5; color: #000000;">{
            </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> multiChoices </span><span style="background-color: #f5f5f5; color: #000000;">=</span> <span style="background-color: #f5f5f5; color: #0000ff;">new</span><span style="background-color: #f5f5f5; color: #000000;"> Array();
            </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">遍历整个下拉菜单</span>
            <span style="background-color: #f5f5f5; color: #0000ff;">for</span><span style="background-color: #f5f5f5; color: #000000;">(</span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> i</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">;i</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">select.options.length;i</span><span style="background-color: #f5f5f5; color: #000000;">++</span><span style="background-color: #f5f5f5; color: #000000;">)
                </span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;">(select.options[i].selected)</span>
<span style="background-color: #f5f5f5; color: #000000;">                   multiChoices.push(select.options[i].value);</span>
<span style="background-color: #f5f5f5; color: #000000;">            alert(</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">多选</span><span style="background-color: #f5f5f5; color: #000000;">"</span> <span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;"> multiChoices);
        }
    }
</span><span style="color: #0000ff;"></span><span style="color: #800000;">script</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span></span>

提示：

在不同操作系统中，选择多个选项的差异：

对于 windows：按住 Ctrl 按钮来选择多个选项
对于 Mac：按住 command 按钮来选择多个选项

由于上述差异的存在，同时由于需要告知用户可以使用多项选择，对用户更友好的方式是使用复选框。

§　　form提交方式

表单的提交方式由method属性的取值决定，所以form提交方式有以下两种：

get 方式：

表单数据将会追加action指定的URL后面，做为URL链接而传递（以查询字符串的形式提交到服务端）。

变量提交的样式为：html元素的name属性=提交的值。多个变量，在URL链接后面以 & 符号隔开。

post方式：

表单数据将附加在请求体（HTML Headers）上被发送出去，并不附加在URL链接后面。

建议：表单通常还是以post方式提交比较好，这样可以不破坏URL，况且URL还有长度限制。

get 与 post 的区别：

1）、get是从服务器上获取数据；post是向服务器传送数据

2）、数据的查询：比如浏览论坛或博客时，URL一般包含了分类、页码数、每页记录数等信息。 get 方式，能一目了然的看到所要查询的信息； post 因为隐藏掉了这些信息，不方便进行查询。

3）、数据安全性：对一项记录，进行更改、添加操作时，get 方式附加在URL上，会泄露数据；post 方式，能隐藏数据，保证数据的安全性。

4）、数据传输量：get 虽然方便查询，但由于是附加在URL上，使得其传送的数据量较小，不能大于2KB；post传送的数据量较大，一般被默认为不受限制。

资源链接

推荐：更多代码详解，请转到代码仓库：https://github.com/Tina-xy/HTML

推荐： Fish Li 博主的 ---- 细说Form(表单)

http://www.cnblogs.com/fish-li/archive/2011/07/17/2108884.html

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Difficulty in updating caching of official account web pages: How to avoid the old cache affecting the user experience after version update?Mar 04, 2025 pm 12:32 PM

The official account web page update cache, this thing is simple and simple, and it is complicated enough to drink a pot of it. You worked hard to update the official account article, but the user still opened the old version. Who can bear the taste? In this article, let’s take a look at the twists and turns behind this and how to solve this problem gracefully. After reading it, you can easily deal with various caching problems, allowing your users to always experience the freshest content. Let’s talk about the basics first. To put it bluntly, in order to improve access speed, the browser or server stores some static resources (such as pictures, CSS, JS) or page content. Next time you access it, you can directly retrieve it from the cache without having to download it again, and it is naturally fast. But this thing is also a double-edged sword. The new version is online,

How to efficiently add stroke effects to PNG images on web pages?Mar 04, 2025 pm 02:39 PM

This article demonstrates efficient PNG border addition to webpages using CSS. It argues that CSS offers superior performance compared to JavaScript or libraries, detailing how to adjust border width, style, and color for subtle or prominent effect

What is the purpose of the <datalist> element?Mar 21, 2025 pm 12:33 PM

The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159

How do I use HTML5 form validation attributes to validate user input?Mar 17, 2025 pm 12:27 PM

The article discusses using HTML5 form validation attributes like required, pattern, min, max, and length limits to validate user input directly in the browser.

What are the best practices for cross-browser compatibility in HTML5?Mar 17, 2025 pm 12:20 PM

Article discusses best practices for ensuring HTML5 cross-browser compatibility, focusing on feature detection, progressive enhancement, and testing methods.

What is the purpose of the <progress> element?Mar 21, 2025 pm 12:34 PM

The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati

What is the purpose of the <meter> element?Mar 21, 2025 pm 12:35 PM

The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex

How do I use the HTML5 <time> element to represent dates and times semantically?Mar 12, 2025 pm 04:05 PM

This article explains the HTML5 <time> element for semantic date/time representation. It emphasizes the importance of the datetime attribute for machine readability (ISO 8601 format) alongside human-readable text, boosting accessibilit

See all articles

Hot AI Tools

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress images for free

Clothoff.io

AI clothes remover

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

Repo: How To Revive Teammates

1 months agoBy尊渡假赌尊渡假赌尊渡假赌

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)

2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hello Kitty Island Adventure: How To Get Giant Seeds

4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

How Long Does It Take To Beat Split Fiction?

3 weeks agoByDDD

R.E.P.O. Save File Location: Where Is It & How to Protect It?

4 weeks agoByDDD

Hot Tools

Zend Studio 13.0.1

Powerful PHP integrated development environment

Notepad++7.3.1

Easy-to-use and free code editor

Atom editor mac version download

The most popular open source editor

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

MinGW - Minimalist GNU for Windows

This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.