如何在javafx中获取label.getWidth()
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How to get label.getWidth() in javafx
提问by baxbear
always when i try to get the width of an Array in Java it just returns 0 and i dont know why. Can somebody explain to me how it is done right?
总是当我尝试在 Java 中获取数组的宽度时，它只返回 0，我不知道为什么。有人可以向我解释它是如何正确完成的吗？
Label label = new Label();
label.setFont(Font.font(label.getFont().getFamily(), 8));
label.setText(""
+ a[i][j].getList().getFirst().getLength()
+ " mal "
+ intToColor(a[i][j].getList().getFirst()
.getColor()));
label.relocate((x1 + x2) / 2 - label.getWidth() / 2, (y1 + y2) / 2);
label.idProperty().set("trackName");
label.setTextFill(Color.web("GREEN"));
field.getChildren().addAll(path, label);
System.out.println(label.getLayoutBounds().getWidth());
System.out.println(label.getWidth());//... also i tested a lot of different getters but i couldn't get the label width (same problem with height)
Hope you got an idea what i have to do.
希望你知道我必须做什么。
@tomsontom
@tomsontom
did this:
做过这个：
label.prefWidth(-1);
label.prefHeight(-1);
label.impl_processCSS(true);
// label.resizeRelocate(x, y, width, height);
System.out.println(label.getWidth());
but it didnt worked - can you explain me more precisely what i need to do?
但它没有用 - 你能更准确地解释我需要做什么吗？
采纳答案by tomsontom
To get the width you need to call prefWidth(-1) and prefHeight(-1) the layout bounds are only set once the control is layouted through resizeRelocate
要获得宽度，您需要调用 prefWidth(-1) 和 prefHeight(-1) 布局边界仅在通过 resizeRelocate 布局控件后才设置
To get the correct width before the stage is shown you also need to call impl_processCSS(true) which is an NONE public API but there's nothing better at the moment IIRC
要在显示舞台之前获得正确的宽度，您还需要调用 impl_processCSS(true)，这是一个 NONE 公共 API，但目前 IIRC 没有比这更好的了
HBox h = new HBox();
Label l = new Label("Hello");
h.getChildren().add(l);
Scene s = new Scene(h);
l.impl_processCSS(true);
System.err.println(l.prefWidth(-1)+"/"+l.prefHeight(-1));
回答by assylias
I don't think the width will be calculated until the Label is shown: add it to a Parent that is visible and you should get a non-zero result.
我认为在显示 Label 之前不会计算宽度：将其添加到可见的 Parent 中，您应该得到一个非零结果。
回答by Warren M. Nocos
Another approach is to calculate the string width of the label's textProperty using Fontloader.computeStringWidth(text, font)which would output the pixel width of the label's textProperty, and is considerably similar to getting the label's width when the label is layouted at the later part.
另一种方法是计算标签的 textProperty 的字符串宽度，使用Fontloader.computeStringWidth(text, font)它会输出标签的 textProperty的像素宽度，这与在后面部分布局标签时获取标签的宽度非常相似。
For an instance:
例如：
FontLoader fontLoader = Toolkit.getToolkit().getFontLoader();
Label label = new Label("My name is Warren. I love Java.");
label.setFont(Font.font("Consolas", FontWeight.THIN, FontPosture.REGULAR, 16));
System.out.println("The label's width is: " + fontLoader.computeStringWidth(label.getText(), label.getFont()));
The output is:
输出是：
The label's width is: 272.70312
To test:
去测试：
FontLoader fontLoader = Toolkit.getToolkit().getFontLoader();
Label label = new Label("My name is Warren. I love Java.");
label.setFont(Font.font("Consolas", FontWeight.THIN, FontPosture.REGULAR, 16));
System.out.println("The label's textProperty string width is: " + fontLoader.computeStringWidth(label.getText(), label.getFont()));
System.out.println("Label's width before layouted: " + label.getWidth());
primaryStage.setScene(new Scene(new StackPane(label), 300, 250));
primaryStage.show();
System.out.println("Label's width after layouted: " + label.getWidth());
Here's the output
这是输出
The label's textProperty string width is: 272.70312
Label's width before layouted: 0.0
Label's width after layouted: 273.0
Comparably, they are the same. Hope this helps.
相比之下，它们是相同的。希望这可以帮助。
回答by ihayet
You can try the following:
您可以尝试以下操作：
func foo()
{
label.layout();
Platform.runLater(()->
{
System.out.println(label.getWidth());
});
}
