如何使用主类在我的项目中实现来自其他类的Swing组件？

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英文:

How do I use a Main class to implement Swing Components from other classes in my project?

问题

我正在开发一个项目，其中我有 "Class1"，"Class2" 和 "Class3"。
Class2 和 Class3 都创建了 JFrame，每个包含各种 JButton、JLabel 和其他 Swing 组件。我如何在 Class1 中引用来自 Class2 的 JButton，并使用动作监听器将 Class2 的可见性设置为 false，Class3 的可见性设置为 true。

我尝试过这样做：在我的主方法中将 Class2 设置为可见没有问题，但一旦我开始实现 Class3，事情就不起作用。

总结：在初始化来自其他类的 JButton 并使用引用该 JButton 的动作监听器时遇到问题。

英文:

Im developing a project in which I have "Class1", "Class2", and "Class3".
Class2 and Class3 both create JFrame's, each containing various JButton's, JLabel's, and other swing components. How do i make so in Class1 I can reffrence the JButton from Class2 and use an action listener to set the Class2's visibilty to false and Class3's visibilty to true.

I Tried This: Setting Class2 to visbile in my main method was no issue, but once i started to implement Class3 things didint work.

Summary: Having Issues initiating a jbutton from an other class and using an action listener that refrences that jbutton.

  1. import java.awt.event.ActionEvent;
  2. import java.awt.event.ActionListener;
  3. import javax.swing.JButton;
  4. import javax.swing.JFrame;
  6. @SuppressWarnings("serial")
  7. public class Class1 extends JFrame implements ActionListener
  8. {
  10.     public static void main(String[] args) {
  11.         Class2 frameFromclass2 = new Class2();
  13.         frameFromclass2.setVisible(true);
  14.     }       
  15.     Class2 buttonMovetoclass3 = new Class2();
  17.     public void actionPerformed(ActionEvent e) {
  19.         if (buttonMovetoclass3 == e.getSource()) {   
  20.             Class2 frameFromclass2 = new Class2();
  22.             frameFromclass2.setVisible(false);
  24.             Class3 frameFromclass3 = new Class3();
  26.             frameFromclass3.setVisible(true);
  28.                     	
  29.         }
  30.     }	
  31. 	
  32. }

答案1

得分: 0

部分你的问题是由于对变量作用域的理解不足引起的。你问题的另一部分是因为方法不太合适。

  1. import java.awt.event.ActionEvent;
  2. import java.awt.event.ActionListener;
  3. import javax.swing.JButton;
  4. import javax.swing.JFrame;
  6. @SuppressWarnings("serial")
  7. public class Class1 extends JFrame implements ActionListener
  8. {
  9.     //这是一个方法。在这个方法内声明的每个变量只能在该方法内访问。
  10.     public static void main(String[] args) {
  11.         //包括这个。
  12.         Class2 frameFromclass2 = new Class2();
  13.         //你在这里使用了它，但不仅它被丢弃了，而且它不能在其他地方使用。
  14.         它被包含在花括号的限制范围内。
  15.         frameFromclass2.setVisible(true);
  16.     }       
  17.     Class2 buttonMovetoclass3 = new Class2();
  19.     public void actionPerformed(ActionEvent e) {
  21.         if (buttonMovetoclass3 == e.getSource()) {   
  22.             //在这里你创建一个新的Class2对象，并赋予它与其他相同的名称，然后隐藏它。
  23.             Class2 frameFromclass2 = new Class2();
  25.             frameFromclass2.setVisible(false);
  26.             //然后在这里你做了相同的事情，但是使用Class3；然后你显示它。
  27.             Class3 frameFromclass3 = new Class3();
  29.             frameFromclass3.setVisible(true);
  30.         }
  31.     }   
  32. }

我们无法看到你的其他类在它们的构造函数中有什么内容，所以我无法确定是否在那里也存在问题。不过，我可以提供更好的替代方案。

通常情况下，即使有弹出窗口或多个“页面”可供使用，你也应该保留一个JFrame。考虑使用多个JPanels，每个对应一种布局。或者你可以使用JTabbedPane，每个选项卡上都可以放置不同的信息。对于登录目的，常见选项是JOptionPane或JDialog。如果你坚持使用多个JFrames，并且想要在它们之间移动组件，应该使用类内的变量来存储信息，然后使用公共方法从其他类访问这些变量。一旦窗口不再使用，你应该销毁它，而不是隐藏它。这里有一个很好的资源，介绍了各种方法。

英文:

Part of your problem is caused by a lack of understanding in terms of variable scope. The other part of your problem is just in approaching this the wrong way.

  1. import java.awt.event.ActionEvent;
  2. import java.awt.event.ActionListener;
  3. import javax.swing.JButton;
  4. import javax.swing.JFrame;
  6. @SuppressWarnings("serial")
  7. public class Class1 extends JFrame implements ActionListener
  8. {
  9.     //This is a method. Every variable declared within this method, 
  10.     //is only accessible from within this method. 
  11.     public static void main(String[] args) {
  12.         //That includes this one. 
  13.         Class2 frameFromclass2 = new Class2();
  14.         //You've used it here, but not only is it then abandoned, but it
  15.         //cannot be used anywhere else. It is contained in a cage of curly braces. 
  16.         frameFromclass2.setVisible(true);
  17.     }       
  18.     Class2 buttonMovetoclass3 = new Class2();
  20.     public void actionPerformed(ActionEvent e) {
  22.         if (buttonMovetoclass3 == e.getSource()) {   
  23.             //Here you create a NEW Class2 object and give it the same
  24.             //name you gave the other, then you hide it.
  25.             Class2 frameFromclass2 = new Class2();
  27.             frameFromclass2.setVisible(false);
  28.             //And then you do the same thing here, but with Class3; then you show it. 
  29.             Class3 frameFromclass3 = new Class3();
  31.             frameFromclass3.setVisible(true);
  32.         }
  33.     }   
  34. }

We aren't able to see what your other classes have in their constructors, so I can't say whether or not there's also a problem happening there. I can, however, offer better alternatives.

Generally you want to keep 1 JFrame, even if you have popup windows or multiple "pages" that can be used. Consider using multiple JPanels, one per layout. Alternatively you can use a JTabbedPane, and have different information on each tab. For login purposes, a common option is the JOptionPane or a JDialog. If you insist on using multiple JFrames and you want to move components between them, variables within your class (not a method) should be used to store information, then use public methods to access those variables from the other classes. Once a window is done being used, however, you should destroy it instead of hide it. Here's a great resource on various ways to do that.

huangapple
  • 本文由 发表于 2023年3月21日 01:51:19
  • 转载请务必保留本文链接：https://go.coder-hub.com/75793667-4.html
  • eclipse
  • java
  • jdialog
  • swing
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