显示 JFrame 后如何执行某些操作

Question

I have this GUI application, and I want to execute a custom action inmediatelly when the user open the application, but after the GUI are shown.

So, I put the call to the action into the public Main() of the JFrame like this:

public Main() {
    initComponents();
    ExecuteAfter();
}

Where ExecuteAfter() is the method that contain the acction, or actions to execute.

This works fine, but not in the way I want. This way, the action executes allways before the JFrame are displayed, that is before the aplication windows appear in the screen. What I want is that execute the action only after the JFrame are displayed, that is after the aplication windows appear in the screen.

I tried put the call into the public static void main(String args[]) because there's where the JFrame is created and displayed. But doesn't work because the method isn't static, and I can't put static that method because it use some components of the JFrame that are already initialized non-static by the IDE.

So, the question is: Where I need to put the call for the action can be executed after the JFrame are displayed on the screen? Or there's other way of doing that?

Thanks in advance!

Answer 1

I used a WindowListener and solved the problem.

Instead of put the call in the constructor public Main() or in the main public static void main(String args[]) which cannot be done, I configured a WindowsListener for do the call. Like that:

private void formWindowOpened(java.awt.event.WindowEvent evt) {
    ExecuteAfter();
}

And works perfectly in the way I want.

Thanks @MadProgrammer for the tip.

Answer 2

If i understand you question, I use a similar case for my project. I was needed to start timer when JFrame show, so this is how i do that.

So i use 2 methods and 1 constructor. First method (exp. Name: prepare GUI), here you can add all thinks what you need to create JFrame, JPanel....and that method I call in constructor. In second method (exp. Name: start GUI) you will add all components to JPanel/s, JPanel/s to JFrame, and set JFrame visible = (true) and then add your method ExecuteAfter(). That second method(prepare GUI) you need to call in main method. I hope that's will help you.