java swing中的setvisible方法挂起系统

Question

我有正在处理的银行gui应用程序,我的jdialog的setvisible方法似乎有问题.在用户撤回有效金额后,我弹出一个简单的对话框,其中显示"正在进行交易".在我的dobackground方法中,我继续轮询以检查是否已收到交易.我尝试使用swingworker,我不明白为什么它不起作用.如果我删除setvisible调用它工作正常,那么为什么setvisible导致系统挂起？这是我的jbutton mouselistener中的代码:

SwingWorker<String,Integer> worker = new SwingWorker<String,Integer>(){

  JDialog waitForTrans = new JDialog((JFrame)null,true);
  public String doInBackground() throws Exception {
     waitForTrans.add(new JLabel("Updating balance in system. Please Wait..."));
     waitForTrans.setMinimumSize(new Dimension(300,100));
     waitForTrans.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
     waitForTrans.setVisible(true);
     Bank.getInstance().sendTransaction(currentPin,"-"+withdraw);
     while(!Bank.getInstance().hasCompletedTransaction){

     }
     return null;

  }

  public void done(){
   try {
        this.get();
       } catch (InterruptedException e) {
        e.printStackTrace();
    } catch (ExecutionException e) {

        e.printStackTrace();
    }
    waitForTrans.setVisible(false);
    newField.setText(String.valueOf(Bank.getInstance().getAccountList().get(currentPin).getBalance()));
  }

 };
 worker.execute();

Answer 1

首先,建议在Swing Event-Dispatch线程中进行所有GUI更新,即使用SwingUtilites该类.

其次,你JDialog是模态的,因此阻塞setVisible(true)调用该方法的线程(在你的情况下是主线程,在下面的例子中是Swing Event-Dispatch Thread).

我没有说下面的代码是完美的,但它应该让你走上正轨......

final JDialog waitForTrans = new JDialog((JFrame) null, true);

SwingWorker worker = new SwingWorker() {

  public String doInBackground() throws Exception {
    Thread.sleep(5000);
    return null;
  }

  public void done() {
    SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        waitForTrans.setVisible(false);
        waitForTrans.dispose();
      }
    });
  }

};

worker.execute();
SwingUtilities.invokeLater(new Runnable() {
  public void run() {
    waitForTrans.add(new JLabel("Please Wait..."));
    waitForTrans.setMinimumSize(new Dimension(300, 100));
    waitForTrans.setVisible(true);
  }
});

希望这可以帮助.

Answer 2

您正在显示模式对话框,因此在关闭对话框之前,后台代码无法执行.

在setVisible之后添加一个System.out.println(...)语句,您将看到它永远不会执行.