lesson3-Qt对话框
一、QDialog类1、对话框的概念
对话框在各种软件中都会使用到,一般用来给用户提示信息或者接收用户反馈的信息,因此对话框是应用程序和用户交互的平台。
对话框是一个顶层窗口,不能嵌入到其他窗口中。
2、对话框的种类
1)、模式对话框,该应用程序的其他窗口不能被访问,必须等待当前对话框消失,显示模式对话框一般调用它的exec()函数
2)、非模式对话框,该应用程序的其他窗口还能继续被访问,显示非模式对话框一般调用它的show()函数
3、QDialog类的父类是QWidget


二、QDialog的派生类
为了方便开发人员的使用,Qt对一些特殊功能的对话框做了封装,提供一套标准的对话框。这些内建对话框提供静态函数便于使用,通常都是调用系统本地的对话框
1、QFileDialog

使用方法:
1、打开文件对话框,返回选择的文件名
QString str = QFileDialog::getOpenFileName(
父窗口,
对话框名字,
默认选择路径,
文件过滤器);
2、根据名字打开文件,成功返回true,失败返回false
QFile file(str);
file.open(QIODevice::ReadWrite);
3、得到一个输入流
QTextStream in(&file);
4、逐行读出输入流
in.readLine();
2、QColorDialog

使用方法:
1、获取调色板
QPalette palette = textEdit->palette();
2、打开颜色对话框,获取颜色
QColor color = QColorDialog::getColor(
palette.color(QPalette::Text), //对话框初始颜色
this //父窗口
);
3、设置调色板颜色
palette->setColor(
QPalette::Text, //要设置的调色板的部位
color //要设置的颜色
);
4、加载调色板
textEdit->setPalette(palette);
GUI为不同的部位分别设置了颜色标志

3、QFontDialog

使用方法:
1、打开字体对话框,获取字体
bool ok;
QFont font = QFontDialog::getFont(&ok);
如果点击对话框的“确定”按钮,那么ok的值就会变为true;如果点击对话框的“取消”按钮,那么ok的值就会变为false
2、设置字体
textEdit->setFont(font);
4、QInputDialog

使用方法:
打开输入对话框,输入的内容会返回
QString str = QInputDialog::getText(
this, //父窗口
“inputDialog”, //窗口标题
“please input”, //输入框上面的标签文字
QLineEdit::Normal, //编辑框的显示方式
QDir::home(), //编辑框默认的内容
ok //回填bool变量
)
5、QProgressDialog

QProgress::setRange(0,100) //设置进度条范围
QProgress::setValue(50) //设置进度条当前值
三、QMessageBox
Qt提供了几种显示信息的消息框,这些消息框都是模态对话框,平时在软件里面会经常用到
1、QMessageBox::question
一个具有标题和文本的消息询问框,开发人员可以根据具体需要定制按钮的个数和按钮的作用

2、QMessageBox::informat
一个具有标题和提示文本的提示消息框,开发人员可以根据具体需要定制按钮的个数和按钮的作用

3、QMessageBox::warning
一个具有标题和文本信息的警示消息框,开发人员可以根据具体需要定制按钮的个数和按钮的作用

4、QMessageBox::critical
一个具有标题和文本信息的致命信息框,开发人员可以根据具体需要定制按钮的个数和按钮的作用

5、QMessageBox::about
一个具有标题和文本的消息框

6、QMessageBox::aboutQt
显示关于Qt的消息框

7、消息按钮的制订

四、QDialog实例
1、头文件
<ol style="margin:0 1px 0 0px;padding-left:40px;" start="1" class="dp-css"><li>#ifndef BUILDINDIALOG_H<br /> </li><li>#define BUILDINDIALOG_H<br /></li><li><br /></li><li>#include <QtGui><br /></li><li><br /></li><li>class buildInDialog : public QDialog<br /></li><li>{<br /></li><li>Q_OBJECT<br /></li><li>public:<br /></li><li>buildInDialog();<br /></li><li>private:<br /></li><li>QPushButton *fileBtn;<br /></li><li>QPushButton *colorBtn;<br /></li><li>QPushButton *fontBtn;<br /></li><li>QPushButton *saveBtn;<br /></li><li>QPushButton *closeBtn;<br /></li><li><br /></li><li>QTextEdit *textEdit;<br /></li><li>private slots:<br /></li><li>void fileSlot();<br /></li><li>void colorSlot();<br /></li><li>void fontSlot();<br /></li><li>void saveSlot();<br /></li><li>void closeSlot();<br /></li><li><br /></li><li>};<br /></li><li><br /></li><li><br /></li><li><br /></li><li>#endif</li></ol>2、实现文件
<ol style="margin:0 1px 0 0px;padding-left:40px;" start="1" class="dp-css"><li>#include "buildInDialog.h"<br /> </li><li><br /></li><li>buildInDialog::buildInDialog()<br /></li><li>{<br /></li><li>fileBtn = new QPushButton("open");<br /></li><li>colorBtn = new QPushButton("color");<br /></li><li>fontBtn = new QPushButton("font");<br /></li><li>saveBtn = new QPushButton("save");<br /></li><li>closeBtn = new QPushButton("close");<br /></li><li><br /></li><li>textEdit = new QTextEdit();<br /></li><li><br /></li><li><br /></li><li>//布局<br /></li><li>QVBoxLayout *vLay = new QVBoxLayout();<br /></li><li>QHBoxLayout *hLay = new QHBoxLayout();<br /></li><li>vLay->addWidget(fileBtn);<br /></li><li>vLay->addWidget(colorBtn);<br /></li><li>vLay->addWidget(fontBtn);<br /></li><li>vLay->addWidget(saveBtn);<br /></li><li>vLay->addWidget(closeBtn);<br /></li><li><br /></li><li>hLay->addWidget(textEdit);<br /></li><li>hLay->addLayout(vLay);<br /></li><li><br /></li><li>setLayout(hLay);<br /></li><li><br /></li><li>connect(fileBtn, SIGNAL(clicked()), this, SLOT(fileSlot()));<br /></li><li>connect(colorBtn, SIGNAL(clicked()), this, SLOT(colorSlot()));<br /></li><li>connect(fontBtn, SIGNAL(clicked()), this, SLOT(fontSlot()));<br /></li><li>connect(saveBtn, SIGNAL(clicked()), this, SLOT(saveSlot()));<br /></li><li>connect(closeBtn, SIGNAL(clicked()), this, SLOT(closeSlot()));<br /></li><li>}<br /></li><li><br /></li><li>void buildInDialog::fileSlot()<br /></li><li>{<br /></li><li>//获取文件名字<br /></li><li>QString str = QFileDialog::getOpenFileName(this, "打开文件", "/", "All File(*.*)");<br /></li><li><br /></li><li>//打开文件<br /></li><li>QFile file(str);<br /></li><li>if(!file.open(QIODevice::ReadWrite))<br /></li><li>return;<br /></li><li>//得到输入流<br /></li><li>QTextStream in(&file);<br /></li><li>//读取数据<br /></li><li>while(!in.atEnd())<br /></li><li>{<br /></li><li>QString st = in.readLine();<br /></li><li>textEdit->append(st);<br /></li><li>}<br /></li><li>}<br /></li><li><br /></li><li>void buildInDialog::colorSlot()<br /></li><li>{<br /></li><li>//获取条色板<br /></li><li>QPalette palette = textEdit->palette();<br /></li><li>//打开对话框,获取颜色<br /></li><li>QColor color = QColorDialog::getColor(palette.color(QPalette::Text), this);<br /></li><li><br /></li><li>if(color.isValid())<br /></li><li>{<br /></li><li>//将颜色放到条色板<br /></li><li>palette.setColor(QPalette::Window, color);<br /></li><li>//加载调色板<br /></li><li>textEdit->setPalette(palette);<br /></li><li>}<br /></li><li><br /></li><li>}<br /></li><li><br /></li><li>void buildInDialog::fontSlot()<br /></li><li>{<br /></li><li>bool ok;<br /></li><li>QFont font = QFontDialog::getFont(&ok);<br /></li><li>if(ok)<br /></li><li>textEdit->setFont(font);<br /></li><li>}<br /></li><li><br /></li><li>void buildInDialog::saveSlot()<br /></li><li>{<br /></li><li>bool ok;<br /></li><li>//获取输入的信息<br /></li><li>QString str = QInputDialog::getText(this, "输入对话框", "请输入名字", QLineEdit::Normal, "wj", &ok);<br /></li><li><br /></li><li>//根据输入的名字打开文件<br /></li><li>QFile file(str);<br /></li><li>file.open(QIODevice::WriteOnly);<br /></li><li>//获取输出流<br /></li><li>QTextStream out(&file);<br /></li><li>//将textEdit的内容写入到out<br /></li><li>out<<textEdit->toPlainText()<<"\n";<br /></li><li>}<br /></li><li><br /></li><li>void buildInDialog::closeSlot()<br /></li><li>{<br /></li><li>QProgressDialog *progress = new QProgressDialog();<br /></li><li>progress->setRange(0, 100);<br /></li><li>for(int i=0; i<=100; i+=10)<br /></li><li>{<br /></li><li>qApp->processEvents();<br /></li><li>progress->setValue(i);<br /></li><li>sleep(1);<br /></li><li>}<br /></li><li>} </li></ol>3、主函数
<ol style="margin:0 1px 0 0px;padding-left:40px;" start="1" class="dp-css"><li>#include "buildInDialog.h"<br /> </li><li>#include <QApplication><br /></li><li><br /></li><li>int main(int argc, char *argv[])<br /></li><li>{<br /></li><li>//设置编码,防止汉字出现乱码<br /></li><li>QTextCodec::setCodecForCStrings(QTextCodec::codecForName("utf-8"));<br /></li><li>QApplication app(argc, argv);<br /></li><li><br /></li><li>buildInDialog dialog;<br /></li><li>dialog.show();<br /></li><li><br /></li><li>return app.exec();<br /></li><li>} </li></ol>

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