JavaFX Label

￡神魔★判官ぃ 2023-10-14 19:00 7阅读 0赞

The JavaFX Label control can display a text or image label inside a JavaFX GUI. The label control must be added to the scene graph to be visible. The JavaFX Label control is represented by the class `javafx.scene.control.Label` .

### Creating a Label ###

You create a label control instance by creating an instance of the `Label` class. Here is a JavaFX Label instantiation example:

Label label = new Label("My Label");

As you can see, the text to display in the label is passed as parameter to the `Label` constructor.

### Adding a Label to the Scene Graph ###

To make the `Label` visible you must add it to the scene graph. This means adding it to a `Scene` object, or as child of a layout which is attached to a `Scene` object.

Here is an example that attaches a JavaFX `Label` to the scene graph:

package com.jenkov.javafx.controls;
    
    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.Label;
    import javafx.stage.Stage;
    
    public class LabelExperiments extends Application  {
    
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            primaryStage.setTitle("HBox Experiment 1");
    
            Label label = new Label("My Label");
    
            Scene scene = new Scene(label, 200, 100);
            primaryStage.setScene(scene);
            primaryStage.show();
        }
    
        public static void main(String[] args) {
            Application.launch(args);
        }
    }

Notice that the `Label` is added directly to the `Scene` object. Normally you would nest the `Label` inside a layout component of some kind. I have left that out here to keep the example simple. See the tutorials about layout components to see how they work.

The result of running the above JavaFX `Label` example is an application that looks like this:

![5837e64efa10470ab02792ba2e7444af.png][]

### Displaying Images in a Label ###

It is possible to display an image inside a label next to the label text. The JavaFX `Label` class contains a constructor that can take a `Node` as extra parameter. Here is a JavaFX label example that adds an image to the label using an [JavaFX ImageView][] component:

package com.jenkov.javafx.controls;
    
    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.Label;
    import javafx.scene.image.Image;
    import javafx.scene.image.ImageView;
    import javafx.stage.Stage;
    
    import java.io.FileInputStream;
    
    
    public class LabelExperiments extends Application  {
    
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            primaryStage.setTitle("HBox Experiment 1");
    
            FileInputStream input = new FileInputStream("resources/images/iconmonstr-home-6-48.png");
            Image image = new Image(input);
            ImageView imageView = new ImageView(image);
    
    
            Label label = new Label("My Label", imageView);
    
            Scene scene = new Scene(label, 200, 100);
            primaryStage.setScene(scene);
            primaryStage.show();
        }
    
        public static void main(String[] args) {
            Application.launch(args);
        }
    }

The result of running the above JavaFX `Label` example is an application that looks like this:

![5e987d0b2404436c8686214f0c87007b.png][]

### Changing the Text of a Label ###

You can change the text of a label using its `setText()` method. This can be done while the application is running. Here is an example of setting the text of a JavaFX Label:

label.setText("New label text");

See the [JavaFX Button tutorial][] for an example that changes the text of a label when a button is clicked.

### Set Label Font ###

You can change the font used by a JavaFX `Label` by calling its `setFont()` method. This is useful if you need to change the size of the text, or want to use a different text style. You can read more about how to create JavaFX fonts in my [JavaFX Fonts][] tutorial. Here is an example of setting the font of a JavaFX `Label`:

Label label = new Label("A label with custom font set.");
    label.setFont(new Font("Arial", 24));

This example tells the `Label` to use the `Arial` font with a size of 24.

url: [JavaFX Label][]

[5837e64efa10470ab02792ba2e7444af.png]: https://img-blog.csdnimg.cn/5837e64efa10470ab02792ba2e7444af.png
[JavaFX ImageView]: https://jenkov.com/tutorials/javafx/imageview.html
[5e987d0b2404436c8686214f0c87007b.png]: https://img-blog.csdnimg.cn/5e987d0b2404436c8686214f0c87007b.png
[JavaFX Button tutorial]: https://jenkov.com/tutorials/javafx/button.html
[JavaFX Fonts]: https://jenkov.com/tutorials/javafx/fonts.html
[JavaFX Label]: https://jenkov.com/tutorials/javafx/label.html