java 用于检查布尔值的 JavaFX 侦听器
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/37785689/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
JavaFX Listener to check for a boolean value
提问by mineshmshah
I have a game with a GUI with a couple of buttons that you press to eventually complete the game.
我有一个带有 GUI 的游戏，你可以按下几个按钮来最终完成游戏。
I have the following boolean to test:
我有以下布尔值要测试：
public boolean complete(){
if (initvalue==finalvaue)){
return true;
}
else {
return false;
}
}
I want to create a listener to check if the game is finished and to print out a message to the user. I think I need to create a SimpleBooleanPropertyfor this to work. But would I need to bind it to the boolean value above?
我想创建一个侦听器来检查游戏是否完成并向用户打印一条消息。我想我需要为此创建一个SimpleBooleanProperty。但是我需要将它绑定到上面的布尔值吗？
What would the best way to go about this?
最好的方法是什么？
回答by DVarga
You can have a BooleanPropertycalled completedPropertyand you can have initvaluePropertyand finalValuePropertyalso to store the points of the game, and then you can simply bind the value of the completedPropertylike
你可以有一个BooleanProperty调用completedProperty，你可以有initvalueProperty，finalValueProperty也可以存储游戏的点数，然后你可以简单地绑定completedProperty类似的值
completedProperty.bind(initValueProperty.isEqualTo(finalValueProperty));
therefore you don't even need a method anymore.
因此，您甚至不再需要方法。
In the example I have just placed a Buttonwhich increments the current value by one on press and I used 3 properties to continuously check the "game" state. As soon as the completedPropertyswitches to "true", a Labelwith text of "Game Over" appears.
在示例中，我刚刚放置了一个Button，它在按下时将当前值增加 1，并且我使用了 3 个属性来连续检查“游戏”状态。一旦completedProperty切换到“true”，就会出现Label带有“Game Over”字样的文字。
Note:I have used IntegerPropertyto store the current and the final value, but you can use any Property.
注意：我曾经使用IntegerProperty过存储当前值和最终值，但您可以使用任何Property.
Example:
例子：
public class Main extends Application {
private IntegerProperty initValueProperty = new SimpleIntegerProperty(0);
private IntegerProperty finalValueProperty = new SimpleIntegerProperty(10);
private BooleanProperty completedProperty = new SimpleBooleanProperty();
@Override
public void start(Stage primaryStage) {
try {
BorderPane root = new BorderPane();
Scene scene = new Scene(root,400,400);
Button buttonPlusOne = new Button("+1");
root.setCenter(buttonPlusOne);
Text currValueText = new Text();
currValueText.textProperty().bind(initValueProperty.asString());
root.setBottom(currValueText);
// Increment current value
buttonPlusOne.setOnAction(e -> initValueProperty.set(initValueProperty.get()+1));
// Bind completed property: initValue equals finalValue
completedProperty.bind(initValueProperty.isEqualTo(finalValueProperty));
completedProperty.addListener((observable, oldValue, newValue) -> {
// Only if completed
if (newValue)
root.setTop(new Label("Game Over"));
});
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
Optionally (as noted by fabian) you can even use a BooleanBindingrather than a property to check the completed state (in this case you don't need completedProperty), like:
可选（如fabian 所述）您甚至可以使用 aBooleanBinding而不是属性来检查完成状态（在这种情况下您不需要completedProperty），例如：
BooleanBinding completed = initValueProperty.isEqualTo(finalValueProperty);
completed.addListener((observable, oldValue, newValue) -> {
// Only if completed
if (newValue)
root.setTop(new Label("Game Over"));
});
To learn about properties in JavaFX this is a really good articleto start with.
要了解 JavaFX 中的属性，这是一篇非常好的入门文章。
