java 图形化小工具Abstract Window Toolit 常用组件：对话框Dialog FileDialog

对话框

Dialog是Window类的子类，是1个容器类，属于特殊组件，对话框是可以独立存在的顶级窗口，因此用法与普通窗口的用法几乎完全一样。但对话框有如下两点需要注意。

(1),对话框通常依赖于其他窗口，就是通常有parent窗口。
(2),对话框有非模式(non-model)和模式(modal)两种，模式(modal)方式当某个模式对话框被打开之后，该模式对话框总是位于它依赖的窗口之上:在模式对话框被关闭之前，它依赖的窗口无法获得焦点。

import java.awt.*;

import java.awt.event.ActionListener;

/**

 * @ClassName DialogTest

 * @projectName: object1

 * @author: Zhangmingda

 * @description： XXX

 * date: 2021/5/5.

 */

public class DialogTest {

    public static void main(String[] args) {

        Frame frame = new Frame("测试新对话框");

        Dialog dia1 = new Dialog(frame,"非模式对话框",false);

        dia1.setBounds(100,100,200,300);

        Dialog dia2 = new Dialog(frame,"模式对话框",true);

        dia2.setBounds(100,100,200,300);

        ActionListener btnClickListener = e -> {

            switch (e.getActionCommand()) {

                case "打开非模式对话框":

                    dia1.setVisible(true);

                    break;

                case "打开模式对话框":

                    dia2.setVisible(true);

                    break;

            }

        };

        Button btn1 = new Button("打开非模式对话框");

        btn1.addActionListener(btnClickListener);

        Button btn2 = new Button("打开模式对话框");

        btn2.addActionListener(btnClickListener);

        frame.setLocation(400,300);

        frame.add(btn1);frame.add(btn2,BorderLayout.SOUTH);

        frame.pack();

        frame.setVisible(true);

    }

}

Dialog有一个子类叫做FileDialog，可以用来选择打开或者保存文件。

示例代码：

新建会话框选择文件，以字符流方式读取文件内容。再将读取的数据另存为文件

import java.awt.*;

import java.io.*;

/**

 * @ClassName FileDialogTest

 * @projectName: object1

 * @author: Zhangmingda

 * @description： XXX

 * date: 2021/5/6.

 */

public class FileDialogTest {

    public static void main(String[] args) {

        Frame frame = new Frame("打开/保存文件窗口");

        Button openFileButton = new Button("打开文件");

        Button saveFileButton = new Button("保存到文件");

        //选择文件对话框

        FileDialog openFileDialog = new FileDialog(frame,"选择文件",FileDialog.LOAD);

        //保存文件对话框

        FileDialog saveFileDialog = new FileDialog(frame,"保存文件",FileDialog.SAVE);

        //打开文件对话框事件

        StringBuffer sb = new StringBuffer(); //读取文件存放字符数据的变量

        openFileButton.addActionListener(e ->{

            openFileDialog.setVisible(true);

            String openFilePath = openFileDialog.getDirectory() + openFileDialog.getFile();

            //用字符流、缓冲流方式打开读取文件，存放为String字符串变量中

            try(BufferedReader br = new BufferedReader(new FileReader(openFilePath))) {

                String line = null;

                while ((line = br.readLine()) != null){

                    sb.append(line + "\n");

                }

                System.out.println(sb);

            } catch (FileNotFoundException ex) {

                ex.printStackTrace();

            } catch (IOException ex) {

                ex.printStackTrace();

            }

        });

        //保存文件对话框事件

        saveFileButton.addActionListener(e ->{

            saveFileDialog.setVisible(true);

            String saveFilePath = saveFileDialog.getDirectory() + saveFileDialog.getFile();

            System.out.println(saveFilePath);

            if (sb.length() != 0){

                try (BufferedWriter bw = new BufferedWriter(new FileWriter(saveFilePath))){

                    bw.write(sb.toString());

                } catch (IOException ex) {

                    ex.printStackTrace();

                }

            }

        });

        frame.add(openFileButton);frame.add(saveFileButton,BorderLayout.SOUTH);

        frame.setLocation(400,300);

        frame.pack();

        frame.setVisible(true);

    }

}

teacher版本：原子化操作变量

AtomicReference<String> fileContent = new AtomicReference<>();

import java.awt.*;

import java.io.*;

import java.util.concurrent.atomic.AtomicReference;

/**

 * @ClassName FileDialogTest

 * @projectName: object1

 * @author: Zhangmingda

 * @description： XXX

 * date: 2021/5/6.

 */

public class FileDialogTestTeacher {

    public static void main(String[] args) {

        Frame frame = new Frame("打开/保存文件窗口");

        Button openFileButton = new Button("打开文件");

        Button saveFileButton = new Button("保存到文件");

        //选择文件对话框

        FileDialog openFileDialog = new FileDialog(frame,"选择文件",FileDialog.LOAD);

        //保存文件对话框

        FileDialog saveFileDialog = new FileDialog(frame,"保存文件",FileDialog.SAVE);

        //打开文件对话框事件

        AtomicReference<String> fileContent = new AtomicReference<>();

        openFileButton.addActionListener(e ->{

            openFileDialog.setVisible(true);

            String openFilePath = openFileDialog.getDirectory() + openFileDialog.getFile();

            //用字符流、缓冲流方式打开读取文件，存放为String字符串变量中

            StringBuffer sb = new StringBuffer(); //读取文件存放字符数据的变量

            try(BufferedReader br = new BufferedReader(new FileReader(openFilePath))) {

                String line = null;

                while ((line = br.readLine()) != null){

                    sb.append(line + "\n");

                }

                System.out.println(sb);

                fileContent.set(sb.toString());

            } catch (FileNotFoundException ex) {

                ex.printStackTrace();

            } catch (IOException ex) {

                ex.printStackTrace();

            }

        });

        //保存文件对话框事件

        saveFileButton.addActionListener(e ->{

            saveFileDialog.setVisible(true);

            String saveFilePath = saveFileDialog.getDirectory() + saveFileDialog.getFile();

            System.out.println(saveFilePath);

            if (fileContent.get() != null){

                try (BufferedWriter bw = new BufferedWriter(new FileWriter(saveFilePath))){

                    bw.write(fileContent.get());

                } catch (IOException ex) {

                    ex.printStackTrace();

                }

            }

            else {

                System.out.println("您还没有打开/读取文件内容");

            }

        });

        frame.add(openFileButton);frame.add(saveFileButton,BorderLayout.SOUTH);

        frame.setLocation(400,300);

        frame.pack();

        frame.setVisible(true);

    }

}

巴特西

java 图形化小工具Abstract Window Toolit 常用组件：对话框Dialog FileDialog

对话框

最新文章

热门文章