我如何检查一个框架是否打开或不在java中？ [英] how can i check that a frame is open or not in java?

问题描述

在netbeans中点击按钮时，我可以打开表单或其他表单。
，例如下面的代码：

  private void button1ActionPerformed（java.awt.event.ActionEvent evt）{
 frame1 fr = new frame1（）; 
 desktop.add（fr）; 
 fr.setVisible（true）;} 
  

但是我想控制当前窗体是打开还是关闭？如果当前窗体是打开的，那么当我点击相同的按钮不会打开当前窗体，直到它关闭了相同的窗体。我怎么能做到这一点？有一些方法像isclosed（），isDisplayable（），但我不知道如何使用这些？请给我建议。

解决方案

您可以使用布尔变量来确定是否允许打开框架。

例子：

  //在一个类中声明布尔值，可以访问
 public final class Allow {
 private Allow（）{} 
 public static Boolean allow_ = true; 
 
 
 
 $ b 
在打开辅助框架的主框架代码中，您可以执行此操作
  if（Allow.allow_ == true）{
 Allow.allow_ = false; 
 secondFrame sFrame_ = new secondFrame（）; 
 sFrame_.setVisible（true）; 
} else {
 //提醒用户框架已经打开
 //我推荐一个JOptionPane，比如这个
 JOptionPane.showMessageDialog（null，这个窗口已经存在打开）; 
} 
  
现在第二个框架已经打开了，现在它只会让你打开如果allow_为true。
 
 
 
现在，当您关闭第二帧时，您可以这样做： 
 
 
  Allow.allow_ = true; 
 secondFrame.this.setVisible（false）; 
 secondFrame.this.dispose（）; 
  
现在第二帧已关闭，现在可以再次打开。
 
i can open a form or another forms when button is clicked in netbeans.
such as the following code
private void button1ActionPerformed(java.awt.event.ActionEvent evt) {                                               
    frame1 fr = new frame1();
    desktop.add(fr);
    fr.setVisible(true);}
but i want to control that is current form is open or close? if current form is open then when i click same button not open current form again until its closed the same form. how can i make it? there is some methods like isclosed(), isDisplayable(), but i dont khow how can i use these? please give me advice.
解决方案
You could use Boolean variables to determine whether or not the allowance of opening a frame.

example:
//declaring the boolean in a class in which both frames can access
public final class Allow {
    private Allow(){}
    public static Boolean allow_ = true;
}
In your main frame code where you open the secondary frame you can do this
if(Allow.allow_ == true) {
    Allow.allow_ = false;
    secondFrame sFrame_ = new secondFrame();
    sFrame_.setVisible(true);
} else {
    //alert the user that the frame is already open
    //I recommend a JOptionPane such as this
    JOptionPane.showMessageDialog(null, "This window is already open");
}
So now the second frame is open, and now it will only let you open it if allow_ is true.

Now when you close the second frame you do this:
Allow.allow_ = true;
secondFrame.this.setVisible(false);
secondFrame.this.dispose();
Now the second frame is closed, and will now be allowed to be opened once again.

                        
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