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HomeJavajavaTutorialHow to implement a simple user login interface in Java?

一、概要

我们可以用java实现简单的登录界面。

How to implement a simple user login interface in Java?

如上效果,直观但也需要一步一步来完成,从界面弹窗的设置,图片的插入,文本框的设置,到登录的按钮,全由代码来实现。

二、分类部分

LoginUI类:实现界面的设置,构建方法,封装好所有的界面开发代码

initUI方法 :1、创建窗体对象;

2、设置窗体的相关属性(标题、尺寸、大小、关闭、可视化);

3、创建组件对象,按钮,输入框;

4、界面窗口添加按钮;

5、按钮添加监听器。

②main方法 :用自己的类创建对象,调用自己的方法 

ButtonAction类:监听器,获取鼠标点击按钮的信息,(继承ActionListener)

我们添加按钮后,需要一个点击按钮后有反应的功能,故设置此类,能在点击按钮后做出反应。

比如此处我们设置初始账户admin,密码123456,可以输入后,点击登录,跳出登录成功的界面。

①成员方法actionPerformed,传入参数(actionPerformed)

②成员变量

public int count = 0;
    //先声明一个输入框的引用地址存储变量;
    public JTextField nameJtf;
    public JTextField pwdJtf;
    public JFrame jf1;

继承ActionListener后,必须重写里面的方法actionPerformed(用ctrl+鼠标左键 看到源文件代码)

此即监听器。

三、代码实现

LoginUI类:实现界面的设置,构建方法,封装好所有的界面开发代码

①initUI方法 :1、创建窗体对象;jf

2、设置窗体的相关属性(标题、尺寸、大小不变、位置、居中显示、关闭、可视化);setTitle,setSize,setResizable,setLocation,setLocationRelativeTo,setDefaultCloseOperation,setVisible.

3、创建组件对象,按钮,输入框,图片标签;JButton,JLabal,JTextField,ImageIcon,

4、界面窗口添加按钮:jf.add()

5、按钮添加监听器。ButtonAction btnactino = new ButtonAction();

btnaction.addActionListener(btnaction).

②main方法 :用自己的类创建对象,调用自己的方法;

//LoginUI类:实现界面的设置,构建方法,封装好所有的界面开发代码
//①initUI方法 :1、创建窗体对象;
//2、设置窗体的相关属性(标题、尺寸、大小、关闭、可视化);
//3、创建组件对象,按钮,输入框;
//4、界面窗口添加按钮;
//5、按钮添加监听器。
//②main方法 :用自己的类创建对象,调用自己的方法 
public class LoginUI {
        //一、界面方法
        public void initUI(){
	    //1:创建一个窗体的对象;	
		
        JFrame jf = new JFrame();
		
	    //2:设置窗体的相关属性:标题,尺寸,关闭选项操作 可视化
		
        jf.setTitle("登录界面");
		jf.setSize(500,800);                //像素单位
		jf.setResizable(false);			    //尺寸固定
		//jf.setLocation(1000,400); 		//位置固定 可更改
		jf.setLocationRelativeTo(null);     //居中显示
		
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //退出方式
 
		jf.setVisible(true);
 
		FlowLayout f1 = new FlowLayout();	//流式布局
		jf.setLayout(f1);
		
	    //3:创建组件对象,按钮,输入框
		//按钮
		JButton btn = new JButton ("登录");
				
		//标签
		JLabel namejla = new JLabel("账号: ");
		JLabel pwdjla = new JLabel ("密码: ");
		
		//输入框
		JTextField nameJtf = new JTextField();
		JTextField pwdJtf = new JTextField();
		
		//图片标签
		ImageIcon imgicon = new ImageIcon("C:\\Users\\Desktop\\picture\\picture.jpeg");//图片插入,更改图片路径,需要注意后缀
	
        JLabel imgjla = new JLabel(imgicon);
		
		//组件设置尺寸
		Dimension dimsize = new Dimension (420,50);
		nameJtf.setPreferredSize(dimsize);
		pwdJtf.setPreferredSize(dimsize);
		
	    //4:界面窗体添加按钮
		jf.add(imgjla);
		jf.add(namejla);
		jf.add(nameJtf);
		jf.add(pwdjla);
		jf.add(pwdJtf);
		jf.add(btn);
		
		//可视化在所有组件加载之后
		jf.setVisible(true);	//可视化 交给系统渲染到屏幕上
	
		//按钮添加监听器
		ButtonAction btnaction = new ButtonAction();
		btn.addActionListener(btnaction); 	
		btnactino.count=100;	
		btnactino.nameJtf= nameJtf;
		btnactino.pwdJtf= pwdJtf;
	} 
        //二、主函数部分
	    public static void main(String[] args) {
	    //创建自己写的类的对象;
		LoginUI loginui = new LoginUI();
        //调用方法
		loginui.initUI();
	}    
}

ButtonAction类:监听器,获取鼠标点击按钮的信息,(继承ActionListener)

public class ButtonAction implements ActionListener{	//监听器
    public int count = 0;
	//先声明一个输入框的引用地址存储变量;
	public JTextField nameJtf;
	public JTextField pwdJtf;
	public JFrame jf1;
	
	//监听器
	public void actionPerformed(ActionEvent e) {
		
		//获取输入框中的字符串
		String nameText = nameJtf.getText();
		String pwdText = pwdJtf.getText();
		
		//比较账号 密码    设置初始账户admin,密码123456
		if(nameText.equals("admin") || nameText.equals("user1")) {
		System.out.println("比较成功!!");
		
		if(pwdText.equals("123456") || pwdText.equals("a123456")) {
			System.out.println("比较成功!!");
	
		//创建一个新窗体弹出
		JFrame jf = new JFrame();
		jf.setTitle("登录响应!!");
		jf.setSize(500,200);
		jf.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		java.awt.FlowLayout f1 = new java.awt.FlowLayout();
		jf.setLayout(f1);
		JLabel jla =new JLabel ("登录成功!!");
		jf.add(jla);
		jf.setVisible(true);
		jf.setLocationRelativeTo(null);//居中显示
		}
	}
	}
}

How to implement a simple user login interface in Java?

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