Question

这应该很简单，不知道为什么我没有得到它。我尝试使用GroupLayout在JFrame（mainWindow）中创建JPanel。我希望面板能够覆盖整个框架的宽度，但是面板的宽度/高度保持为0（即使框架加载并且面板覆盖了所有框架）。谁能帮我？不确定我错过了什么。

panel = new JPanel();
Container pane = mainWindow.getContentPane();
GroupLayout gl = new GroupLayout(pane);
pane.setLayout(gl);
gl.setAutoCreateContainerGaps(false);
gl.setHorizontalGroup(gl.createSequentialGroup().addComponent(panel));
gl.setVerticalGroup(gl.createSequentialGroup().addComponent(panel));
// panel.getWidth() and panel.getHeight() both return 0 here

Answer 1

panel = new JPanel();
Container pane = mainWindow.getContentPane();
GroupLayout gl = new GroupLayout(pane);
pane.setLayout(gl);
gl.setAutoCreateContainerGaps(false);
gl.setHorizontalGroup(gl.createSequentialGroup().addComponent(panel));
gl.setVerticalGroup(gl.createSequentialGroup().addComponent(panel));
// ++++++++++++  editing start
// force do layout subcomponents and rendering
mainWindow.pack();
// ++++++++++++  editing end
System.out.println("w:" + panel.getWidth() + " h:" + panel.getHeight());

Swing JPanel布局管理器

1 个答案: