Java JPanel removeAll 不会删除以前的组件
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JPanel removeAll doesn't get rid of previous components
提问by jaybee
I have a swing application in which I display images in a JPanel. If the app is unable to produce the image I want to remove the previous one from the JPanel and replace it with a JTextField and message. I can add the text field , but it's drawn on top of the previous contents, which is itself a subclass of JPanel. Here's what I have:
我有一个 Swing 应用程序，在其中我在 JPanel 中显示图像。如果应用程序无法生成图像，我想从 JPanel 中删除前一个图像并将其替换为 JTextField 和消息。我可以添加 text field ，但是它是在前面的内容之上绘制的，它本身是 JPanel 的子类。这是我所拥有的：
private void displayMessage(String message) {
JTextField tf = new JTextField(message);
cdPanel.removeAll();
cdPanel.add(tf, BorderLayout.NORTH);//tried lots of variations, inc. no layout
cdPanel.validate();
}
How can I get cdPanel to completely redraw itself?
我怎样才能让 cdPanel 完全重绘自己？
采纳答案by nIcE cOw
You can simply try calling :
您可以简单地尝试调用：
cdPanel.revalidate();
cdPanel.repaint(); // This is required in some cases
instead of
代替
cdPanel.validate();
回答by trashgod
As you are dealing with unpredictable latency, use a SwingWorkerto do the loading in the background, as shown here. The example uses pack()to resize the label to that of the image, but you may want to use a fixed-size grid and scale the images, as shown here.
当你在处理不可预测的延迟，用SwingWorker做负载的背景下，如图所示这里。例子中使用pack()的标签调整到的图像，但你可能需要使用一个固定大小的网格和缩放图像，如图所示这里。
