java 如何将 jTextArea 设置为具有与其包含的文本大小相匹配的高度（以避免滚动条）
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How to set jTextArea to have height that matches the size of a text it contains (to avoid scrollbars)
提问by celicni
This problem looks trivial, but I can't find the solution.
这个问题看起来微不足道，但我找不到解决方案。
When I create a form it contains a JTextArea. I want to put large constant text in it. If the text is say 1000 lines long, I want my JTextAreato be 1000 lines high (to be large enough to display the entire text without scrollbars). JTextAreais inside a panel which can have scrollbar so it is not a problem when it gets too large (there are two JTextAreain that panel.. something like in a diff tool). Does anybody knows how can I achieve this? Thanks.
当我创建一个表单时，它包含一个JTextArea. 我想在其中放入大的常量文本。如果文本长 1000 行，我希望我的文本JTextArea高 1000 行（足够大以显示没有滚动条的整个文本）。JTextArea位于一个可以有滚动条的面板内，因此当它变得太大时它不是问题（JTextArea该面板中有两个......类似于差异工具中的东西）。有谁知道我怎样才能做到这一点？谢谢。
采纳答案by akf
The BorderLayoutwill handle the scrollbar out of the box if you simply put your JTextAreain a JScrollPanebefore you add it to your JPanel. FlowLayout, on the other hand, does not. It will not display the scroll bar unless, as @Xorty intimates, you call setPreferedSize()on your JScrollPaneand give it the dimension that you would like.
在BorderLayout将处理滚动条开箱，如果你只是把你JTextArea的JScrollPane，你把它添加到你的面前JPanel。 FlowLayout，另一方面，没有。它不会显示滚动条，除非，正如@Xorty 暗示的那样，你调用setPreferedSize()你的JScrollPane并给它你想要的尺寸。
回答by Taisin
You can also use something like this (limited width, height depending on text, useful when showing info messages):
你也可以使用这样的东西（有限的宽度，高度取决于文本，在显示信息消息时很有用）：
public JTextArea createTextAreaFitToText(String message, Dimension minimalSize){
JTextArea aMessagePanel = new JTextArea();
aMessagePanel.setText(message);
/*for modelToView to work, the text area has to be sized. It doesn't matter if it's visible or not.*/
aMessagePanel.setPreferredSize(minimalSize);
aMessagePanel.setSize(minimalSize);
Rectangle r = aMessagePanel.modelToView(aMessagePanel.getDocument().getLength());
Dimension d = new Dimension(minimalSize.width, r.y + r.height);
aMessagePanel.setPreferredSize(d);
return aMessagePanel;
}
回答by sushant goel
To increase or decrease the height of JTextArea. When a text is entered, call for getPreferredSize() of JTextArea- it'll give you the size needed to display the whole text. After that use setPrefferedSize() of JScrollPane to set the size of JTextArea
增加或减少 JTextArea 的高度。当输入文本时，调用 JTextArea 的 getPreferredSize() - 它会给你显示整个文本所需的大小。之后使用 JScrollPane 的 setPrefferedSize() 来设置 JTextArea 的大小
回答by Xorty
Well, first of all : it's JTextArea not jTextArea.
好吧，首先：它是 JTextArea 而不是 jTextArea。
Now - put JTextArea into JScrollPane. When a text is entered, call for getPreferedSize()of JScrollPane - it'll give you precise size needed to display whole text. Also, I never use other LayoutManager than 'Free Design' from NetBeans Swing builder - so I am not sure how other LayoutManagers will behave there.
现在 - 将 JTextArea 放入 JScrollPane。当输入文本时，调用getPreferedSize()JScrollPane - 它会给你显示整个文本所需的精确大小。此外，除了来自 NetBeans Swing 构建器的“自由设计”之外，我从不使用其他 LayoutManager - 所以我不确定其他 LayoutManager 在那里的表现。
