在FormLayout

Question

我是SWT GUI开发的新手。我正在使用SWT开发Eclipse插件。基本上，我想要第二个无线电选项组下面的两个无线电选项组和一些文本框;如下所示。

    Heading1
    . A radio button
    . B radio button
    Heading2
    . C radio button
    . D radio button
    Textbox1 Textbox2 Textbox3

由于我需要相对于彼此的文本框，我使用了FormLayout 。但它给了我例外：

  

引起：java.lang.ClassCastException：org.eclipse.swt.layout.FormData无法强制转换为org.eclipse.swt.layout.GridData *

但我没有使用GridData。 例外情况发生在第129行。 我无法相对于Textbox1添加Textbox2。我的代码如下。

        Shell sh = new Shell(parent_shell,SWT.PRIMARY_MODAL | SWT.TRAIL | SWT.CASCADE);
        System.out.println("execute");
        FormLayout fL = new FormLayout();
        sh.setLayout(fL);
        sh.setText("Configure");

        sh.setSize(330,300);
        sh.setActive();

        Composite composite = new Composite( sh, SWT.NONE );
         GridLayout layout = new GridLayout();
         layout.marginWidth = 0;
         layout.marginHeight = 0;
         composite.setLayout( layout );

         FormData fd = new FormData(); //line 100
         fd.top = new FormAttachment(0,0);//line 101
         fd.left = new FormAttachment(0,0);//line 102
         //fd.right = new FormAttachment(26);//line 103
         //fd.bottom = new FormAttachment(10);//line 104
         composite.setLayoutData( fd );

         RadioGroupFieldEditor rgfe = new RadioGroupFieldEditor("User Choice",
                 "Heading1", 1, new String[][]{
             {"A radio button","a"},{"B radio button","b"}
         }, composite,false);

         RadioGroupFieldEditor rgfe1 = new RadioGroupFieldEditor("User Choice1",
                 "Heading2", 1, new String[][]{
             {"C radio button","c"},{"D radio button","d"}
         }, composite,false);



         Text ol = new Text(composite,SWT.READ_ONLY);
            ol.setText("Output Location");
            ol.setEnabled(false);

//              FormData fd1 = new FormData();
//              fd.top = new FormAttachment(fd);
//              fd.left = new FormAttachment(1);
//              fd.right = new FormAttachment(26);
//              fd.bottom = new FormAttachment(10);
//              ol.pack();
//              ol.setLayoutData(fd1); //line 129 --> exception occurs




         while (!sh.isDisposed()) {
              if (!parent_display.readAndDispatch()) {
                  parent_display.sleep();
              }
            }

    }

Answer 1

RadioGroupFieldEditor假设其父级设置为GridLayout。

我建议您将RadioGroupFieldEditor嵌入到具有Composite集的单独GridLayout中。然后，您可以将FormData附加到Composite以控制其布局。

例如：

Composite composite = new Composite( sh, SWT.NONE );
GridLayout layout = new GridLayout();
layout.marginWidth = 0;
layout.marginHeight = 0;
composite.setLayout( layout );
FormData compositeFormData = new FormData();
...
composite.setLayoutData( compositeFormData );
RadioGroupFieldEditor fieldEditor = new RadioGroupFieldEditor( ..., composite, ... );