blocks|key|1466483|text|最初创建图形用户界面(即GUI+gui+=+new+GUI();)时，请保存该引用，以便在需要访问成员s时使用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1466484|当您创建一个新的图形用户界面对象时，这个新对象从未被用户操作过，因此它的s值就是"String"。您需要持有对原始对象的引用。|1466485|entityMap^0|C|K|1F|1|0|10|1|14|8|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

When you initially create the GUI (i.e. <code>GUI gui = new GUI();</code>), save that reference for when you want to access the member <code>s</code>.

When you create a new GUI object, that new object was never manipulated by the user, so its <code>s</code> value is just <code>"String"</code>. You need to hold the reference to the original object.

blocks|key|1335196|text|在这篇文章下面的评论中，我和其他两个人决定你应该学习java语言，研究面向对象编程的概念(包括对象作用域)，然后学习如何实现正确的事件处理代码-有几种方法可以实现你想要的，我建议结合我提供的代码和上面Welbog提供的参考建议(当然，这将需要修改我的代码，但如果你的主类在其他地方，实际上不是很多)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1335197|基本上，google+a+java+tutorial+(或者买一本书/“获取”一本书)，如果你知道一些基本概念，就跳到面向对象的部分。|offset|length|style|BOLD|1335198|如果我遵循你想要的，下面是一些框架代码：|1335199|//+imports

public+class+GUI+extends+JFrame+implements+ActionListener+{
++++public+String+s+=+"String";

++++public+GUI()+{
++++++++//+initializer+code+for+buttons
++++++++btn1.addActionListener(this);
++++++++btn2.addActionListener(this);
++++}

++++public+void+actionPerformed(ActionEvent+e)+{
++++++++if(s+==+"???")
++++++++++++s+=+"this";
++++++++else
++++++++++++s+=+"that";
++++}

++++//+other+methods

}|code-block|syntax|javascript|1335200|entityMap^0|0|4|1R|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|U|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|V|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

in the comments below this post, myself and 2 other individuals have determined that you should learn the java langauge, research the notion of object oriented programming (including object scope), and then learn how to implement the proper event handling code - there are several ways in which you can accomplish what you want, i would suggest a combination of the code i provided along with the reference suggestion supplied by Welbog up above (this of course, will require modification of my code, but not much actually if your main class is somewhere else)

basically, google a java tutorial (or buy a book/"acquire" a book), and if you know some basic concepts skip ahead to the object-oriented part.

if i follow what you want, here's some skeleton code:

<pre><code>// imports

public class GUI extends JFrame implements ActionListener {
 public String s = "String";

 public GUI() {
 // initializer code for buttons
 btn1.addActionListener(this);
 btn2.addActionListener(this);
 }

 public void actionPerformed(ActionEvent e) {
 if(s == "???")
 s = "this";
 else
 s = "that";
 }

 // other methods

}
</code></pre>

blocks|key|3781857|text|更好的做法可能是将第一个表单的状态传递给第二个表单，或者让第一个表单实时通知第二个表单某个特定事件已经发生。否则，您将需要将第一个表单的引用传递给第二个表单，以执行您正在尝试的比较IE：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3781858|public+class+SecondForm+{
++++private+FirstForm+_firstForm+=+null;
++++public+SecondForm(FirstForm+firstForm){
++++++++_firstForm+=+firstForm;
++++}

++++...

++++if(_firstForm.s+==+"comparison"){
++++++++...
++++}
}

SecondForm+secondForm+=+new+SecondForm(this);|code-block|syntax|javascript|3781859|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

It is probably better practice to pass the state of your first form to the second form or have the first form inform the second form that a particular event has occurred in real time. Otherwise you would need to pass a reference of the first form to the second form to do the comparison you are trying IE:

<pre><code>public class SecondForm {
 private FirstForm _firstForm = null;
 public SecondForm(FirstForm firstForm){
 _firstForm = firstForm;
 }

 ...

 if(_firstForm.s == "comparison"){
 ...
 }
}

SecondForm secondForm = new SecondForm(this);
</code></pre>

blocks|key|1466568|text|创建一个包含按钮(名称)的额外值。当您单击appropiate按钮并从不同的类中读出它时，更改该值。基本上与%25s的想法相同|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1466569|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

create an extra value that holds the button(name). Change the value when you click on the appropiate button and read it out from a different class.
Basicly the same idea as s

blocks|key|1466588|text|很难破解你的问题。但是一般来说，如果你想知道是哪个按钮引发了一个事件，可以给每个按钮(或者它的型号)添加一个不同的ActionListener。尽可能保持代码的整洁和简单。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1466589|entityMap^0|1L|E|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

It's very difficult to decipher your question. But in general, if you want to know which button it was that caused an event, add a different <code>ActionListener</code> to each one (or its model). Keep the code as clean and simple as possible.

blocks|key|5250180|text|我会使用侦听器来观察'string‘变量的状态。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5250181|public+class+Gui
{
++++public+static+final+String+STRING_PROPERTY+=+"string";
++++private+String+string+=+"String";
++++private+PropertyChangeSupport+propertyChangeSupport+=+new+PropertyChangeSupport(this);

++++private+void+setString(String+string)
++++{
++++++++String+oldValue+=+this.string;
++++++++this.string+=+string;
++++++++propertyChangeSupport.firePropertyChange(STRING_PROPERTY,+oldValue,+this.string);
++++}

++++public+void+addPropertyChangeListener(String+propertyName,+PropertyChangeListener+listener)
++++{
++++++++propertyChangeSupport.addPropertyChangeListener(propertyName,+listener);
++++}
}|code-block|syntax|javascript|5250182|这段代码只是演示了如何向您的类添加propertyChangeListener支持。对知道“string”的值感兴趣的类将实现PropertyChangeListener，并通过“addPropertyChangeListener”方法添加到其中。|5250183|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I would use a listener for observing the state of the 'string' variable.

<pre><code>public class Gui
{
 public static final String STRING_PROPERTY = "string";
 private String string = "String";
 private PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);

 private void setString(String string)
 {
 String oldValue = this.string;
 this.string = string;
 propertyChangeSupport.firePropertyChange(STRING_PROPERTY, oldValue, this.string);
 }

 public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener)
 {
 propertyChangeSupport.addPropertyChangeListener(propertyName, listener);
 }
}
</code></pre>

This snippet just demonstrates how to add propertyChangeListener support to your class. The class that is interested in knowing the value of 'string' would implement PropertyChangeListener and be added to through the 'addPropertyChangeListener' method.

blocks|key|1466698|text|您可以对每个按钮使用ActionListener和操作命令，如以下代码所示|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1466699|public+class+GUI++extends+JFrame+implements+ActionListener
{
++public+static+final+String+BUTTON_1_PRESSED+=+"BUTTON_1_PRESSED";
++public+static+final+String+BUTTON_2_PRESSED+=+"BUTTON_2_PRESSED";

++public+String+s+=+"String";

++public+GUI()
++{
++++//+create+buttons
++++button1.addActionListener(this);
++++button1.setActionCommand(BUTTON_1_PRESSED);
++++button2.addActionListener(this);
++++button2.setActionCommand(BUTTON_2_PRESSED);
++}

++public+void+actionPerformed(ActionEvent+e)+
++{
++++if(e.getActionCommand().equals(BUTTON_1_PRESSED))
++++{
++++++s+=+"this";
++++}
++++else+if(e.getActionCommand().equals(BUTTON_2_PRESSED))
++++{
++++++s+=+"that";
++++}
++}
}|code-block|syntax|javascript|1466700|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You could use an ActionListener and an action command on each button as shown in this code

<pre><code>public class GUI extends JFrame implements ActionListener
{
 public static final String BUTTON_1_PRESSED = "BUTTON_1_PRESSED";
 public static final String BUTTON_2_PRESSED = "BUTTON_2_PRESSED";

 public String s = "String";

 public GUI()
 {
 // create buttons
 button1.addActionListener(this);
 button1.setActionCommand(BUTTON_1_PRESSED);
 button2.addActionListener(this);
 button2.setActionCommand(BUTTON_2_PRESSED);
 }

 public void actionPerformed(ActionEvent e) 
 {
 if(e.getActionCommand().equals(BUTTON_1_PRESSED))
 {
 s = "this";
 }
 else if(e.getActionCommand().equals(BUTTON_2_PRESSED))
 {
 s = "that";
 }
 }
}
</code></pre>

I am currently working on some code with which I am having some trouble. 

I have two buttons on a GUI. If one button is pressed it assigns a value to a string a value to reflect this. 

The other button is the same except that a different value is assigned to the string.

This String is created at the beginning before the constructor in the following manner: 

<pre><code>public string s = "String"; // public so I can call it in another class
</code></pre>

The problem comes when I want to find out which button was pressed in another class. I want to see what <code>s</code> is so I have to create an instance of that class GUI:

<pre><code>gui = new GUI(); 
</code></pre>

This then resets the value of <code>s</code> to "String" again and this ruins my comparison.

Is there any way I can get around this?

I've tried lots of ideas but nothing seems to work.

creating instances of classes

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我目前正在处理一些代码，我遇到了一些麻烦。我在GUI上有两个按钮。如果一个按钮被按下，它会将一个值赋给一个字符串，一个值来反映这一点。除了为字符串分配了不同的值之外，另一个按钮与此按钮相同。此字符串是在构造函数之前的开头创建的，其方式如下：public string s = "String"; // public so...

问创建类的实例
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