java 警报对话框中的 JavaFX 默认焦点按钮
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JavaFX default focused button in Alert Dialog
提问by thibault
Since jdk 8u40, I'm using the new javafx.scene.control.AlertAPI to display a confirmation dialog. In the example below, "Yes" button is focused by default instead of "No" button:
从 jdk 8u40 开始，我使用新的javafx.scene.control.AlertAPI 来显示确认对话框。在下面的示例中，“是”按钮默认为焦点，而不是“否”按钮：
public boolean showConfirmDialog(String title, String header, String content, AlertType alertType) {
final Alert alert = new Alert(alertType);
alert.setTitle(title);
alert.setHeaderText(header);
alert.setContentText(content);
alert.getButtonTypes().clear();
alert.getButtonTypes().addAll(ButtonType.YES, ButtonType.NO);
final Optional<ButtonType> result = alert.showAndWait();
return result.get() == ButtonType.YES;
}
And I don't know how to change it.
我不知道如何改变它。
EDIT :
编辑 ：
Here a screenshot of the result where "Yes" button is focused by default :
这是默认情况下“是”按钮聚焦的结果截图：
回答by crusam
I am not sure if the following is the way to usually do this, but you could change the default button by looking up the buttons and setting the default-behavior yourself:
我不确定以下是否是通常执行此操作的方法，但是您可以通过查找按钮并自己设置默认行为来更改默认按钮：
public boolean showConfirmDialog(String title, String header, String content, AlertType alertType) {
final Alert alert = new Alert(alertType);
alert.setTitle(title);
alert.setHeaderText(header);
alert.setContentText(content);
alert.getButtonTypes().clear();
alert.getButtonTypes().addAll(ButtonType.YES, ButtonType.NO);
//Deactivate Defaultbehavior for yes-Button:
Button yesButton = (Button) alert.getDialogPane().lookupButton( ButtonType.YES );
yesButton.setDefaultButton( false );
//Activate Defaultbehavior for no-Button:
Button noButton = (Button) alert.getDialogPane().lookupButton( ButtonType.NO );
noButton.setDefaultButton( true );
final Optional<ButtonType> result = alert.showAndWait();
return result.get() == ButtonType.YES;
}
回答by Sheepy
A simple function thanks to crusam:
感谢 crusam 的简单功能：
private static Alert setDefaultButton ( Alert alert, ButtonType defBtn ) {
DialogPane pane = alert.getDialogPane();
for ( ButtonType t : alert.getButtonTypes() )
( (Button) pane.lookupButton(t) ).setDefaultButton( t == defBtn );
return alert;
}
Usage:
用法：
final Alert alert = new Alert(
AlertType.CONFIRMATION, "You sure?", ButtonType.YES, ButtonType.NO );
if ( setDefaultButton( alert, ButtonType.NO ).showAndWait()
.orElse( ButtonType.NO ) == ButtonType.YES ) {
// User selected the non-default yes button
}
回答by José Pereda
If you have a look at (private) ButtonBarSkinclass, there is a method called doButtonOrderLayout()that performs the layout of the buttons, based in some default OS behavior.
如果您查看（私有）ButtonBarSkin类，就会发现有一个方法doButtonOrderLayout()可以根据某些默认的操作系统行为来执行按钮的布局。
Inside of it, you can read this:
在其中，您可以阅读以下内容：
/* now that all buttons have been placed, we need to ensure focus is set on the correct button. [...] If so, we request focus onto this default button. */
/* 现在已经放置了所有按钮，我们需要确保焦点设置在正确的按钮上。[...] 如果是这样，我们请求关注这个默认按钮。*/
Since ButtonType.YESis the default button, it will be the one focused.
由于ButtonType.YES是默认按钮，因此它将成为焦点。
So @ymene answer is correct: you can change the default behavior and then the one focused will be NO.
所以@ymene 答案是正确的：您可以更改默认行为，然后重点将是NO.
Or you can just avoid using that method, by setting BUTTON_ORDER_NONEin the buttonOrderProperty(). Now the first button will have the focus, so you need to place first the NObutton.
或者您可以通过BUTTON_ORDER_NONE在buttonOrderProperty(). 现在第一个按钮将获得焦点，因此您需要先放置NO按钮。
alert.getButtonTypes().setAll(ButtonType.NO, ButtonType.YES);
ButtonBar buttonBar=(ButtonBar)alert.getDialogPane().lookup(".button-bar");
buttonBar.setButtonOrder(ButtonBar.BUTTON_ORDER_NONE);
Note that YESwill still have the default behavior: This means NOcan be selected with the space bar (focused button), while YESwill be selected if you press enter (default button).
请注意，YES仍将具有默认行为：这意味着NO可以使用空格键（焦点按钮）YES选择，而如果按 Enter（默认按钮）将被选择。
Or you can change also the default behavior following @crusam answer.
或者您也可以更改@crusam 回答后的默认行为。
