在不同的类中使用 JTextArea

Question

I have a class for my GUI which I created using Swing UI Designer. All the components were automatically made private but now I need output some text in a variable called consoleTextArea from outside of the UI.class When I set consoleTextArea to public static I get an error saying "UI.form: Cannot bind: field is static: indeed.UI.consoleTextArea"

...
public static JTextArea consoleTextArea;
...

...
UI.consoleTextArea.setText("abc");
...

\\src\\indeed\\UI.form: Cannot bind: field is static: indeed.UI.consoleTextArea

Answer 1

You can change the value of your label/textArea, through an instance of your UI class.

public class UI {

  // ...

  private TextArea consoleTextArea = new TextArea();
  //
  public void setTextInTextArea(String text) {
    this.consoleTextArea.setText(text);
  }
}

Having setters like this, you can manipulate your textArea from within a different class. This other class, however, must have access to the instance of UI, either instantiate it itself, or getting it passed as a parameter

public class OtherClass {
  UI ui = new UI();

  public void doSomething() {
    ui.setTextInTextArea("New text");
  }

}

or something like:

public class OtherClass {
  public void doSomething(UI ui) {
    ui.setTextInTextArea("New Text");
  }
}

Answer 2

Instead of making the field public (not static public ) you should rather add a method like this to your class:

public void setConsoleTextArea(String value) { consoleTextArea.setText(value); }

Then you can do

UI.setConsoleTextArea("abc");

without having to mess with the consoleTextArea field that is automatically generated.