java - 使用 "setlayout(null)"时小部件行为异常

Question

我在代码中执行以下调用:

...
setLayout(null);
...

我试图通过指定按钮和文本字段的 x 和 y 坐标来放置按钮和文本字段。

运行程序(使用 Eclipse 或 BlueJ)时的问题是，我需要在面板上运行到按钮和文本字段的位置，以便分别查看按钮和文本字段。

当我找到文本字段时，它很小。仅当我开始编写时，它才会采用我指定的大小。

有谁知道怎么解决吗？

Answer 1

1. 避免 setLayout (null)，除非你有充分的理由。您可以在这里了解布局管理器:http://docs.oracle.com/javase/tutorial/uiswing/layout/using.html

2. 如果您仍想使用空布局，则必须设置组件的宽度和高度，而不仅仅是其 x 和 y 位置(请参阅 setSize 方法)。

来自上述链接:

Although we strongly recommend that you use layout managers, you can perform layout without them. By setting a container's layout property to null, you make the container use no layout manager. With this strategy, called absolute positioning, you must specify the size and position of every component within that container. One drawback of absolute positioning is that it does not adjust well when the top-level container is resized. It also does not adjust well to differences between users and systems, such as different font sizes and locales.