嵌套的 if 语句在另一个嵌套的 if 语句中没有捕获

Question

我的 java 下面的代码具有 3 个标签，分别称为 button1、button2 和 button3。当用户导入图像时，当且仅当 button1 上没有图像时，它应该首先转到 button1。然后下次导入图像时，当且仅当 button1 上有图像时，它应该转到按钮。当且仅当 button1 和 button 上有图像时，第三次图像才应该放在 button3 上。该代码适用于 button1 和 button2 但不适用于 button3。所以在 else{.

中开始的嵌套 if 语句中存在问题

  importBtn.addActionListener(new ActionListener() {

         public void actionPerformed(ActionEvent e) {


           JFileChooser file = new JFileChooser();
           file.setCurrentDirectory(new File(System.getProperty("user.home")));
           //filter the files
           FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpg","gif","png");
           file.addChoosableFileFilter(filter);
           int result = file.showSaveDialog(null);


           if(result == JFileChooser.APPROVE_OPTION){

               //NotWorking make check null not text
               if  (button1.getIcon() == null) {
                   File selectedFile = file.getSelectedFile();
                   String path = selectedFile.getAbsolutePath();
                   button1.setIcon(ResizeImage(path));   
               }
               else {
                    if  ((button1.getIcon() != null) && (button3.getIcon()) == null){
                        File selectedFile = file.getSelectedFile();
                        String path = selectedFile.getAbsolutePath();
                        button2.setIcon(ResizeImage(path));   
                        }



                        if  ((button1.getIcon() != null) && (button2.getIcon()) != null){
                            File selectedFile = file.getSelectedFile();
                            String path = selectedFile.getAbsolutePath();
                            button3.setIcon(ResizeImage(path));  



               }
               }



           }


           else if(result == JFileChooser.CANCEL_OPTION){
               System.out.println("No File Select");
           }
         }
     });

Answer 1

试试这个：

importBtn.addActionListener(new ActionListener() {

         public void actionPerformed(ActionEvent e) {


           JFileChooser file = new JFileChooser();
           file.setCurrentDirectory(new File(System.getProperty("user.home")));
           //filter the files
           FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpg","gif","png");
           file.addChoosableFileFilter(filter);
           int result = file.showSaveDialog(null);


           if(result == JFileChooser.APPROVE_OPTION){

               //NotWorking make check null not text
               if  (button1.getIcon() == null) {
                   File selectedFile = file.getSelectedFile();
                   String path = selectedFile.getAbsolutePath();
                   button1.setIcon(ResizeImage(path));   
               }
               else {
                    if  (button2.getIcon() == null){
                        File selectedFile = file.getSelectedFile();
                        String path = selectedFile.getAbsolutePath();
                        button2.setIcon(ResizeImage(path));   
                        } else{
                           if  (button3.getIcon() == null){
                               File selectedFile = file.getSelectedFile();
                               String path = selectedFile.getAbsolutePath();
                               button3.setIcon(ResizeImage(path));  

                           }

                        }
               }



           }


           else if(result == JFileChooser.CANCEL_OPTION){
               System.out.println("No File Select");
           }
         }
     });

Answer 2

你可以试试这个。

importBtn.addActionListener(new ActionListener() {

    public void actionPerformed(ActionEvent e) {


      JFileChooser file = new JFileChooser();
      file.setCurrentDirectory(new File(System.getProperty("user.home")));
      //filter the files
      FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpg","gif","png");
      file.addChoosableFileFilter(filter);
      int result = file.showSaveDialog(null);


      if(result == JFileChooser.APPROVE_OPTION){

          File selectedFile = file.getSelectedFile();
          String path = selectedFile.getAbsolutePath();
          //NotWorking make check null not text
          if  (button1.getIcon() == null) 
          {
              button1.setIcon(ResizeImage(path));   
          }
          else if (button2.getIcon() == null)
          {
              button2.setIcon(ResizeImage(path));
          } 
          else if (button3.getIcon() == null)
          {
              button3.setIcon(ResizeImage(path));  
          }
          else 
          {
              //image set on all three
          }
      }
      else if(result == JFileChooser.CANCEL_OPTION){
          System.out.println("No File Select");
      }
    }
});

记住要始终保持简单。

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