JavaFX ToggleButton

我会带着你远行 2023-10-14 20:22 12阅读 0赞

A JavaFX ToggleButton is a button that can be selected or not selected. Like a button that stays in when you press it, and when you press it the next time it comes out again. Toggled - not toggled. The JavaFX ToggleButton is represented by the class `javafx.scene.control.ToggleButton` .

### Creating a ToggleButton ###

You create a JavaFX ToggleButton by creating an instance of the `ToggleButton` class. Here is an example of creating a JavaFX `ToggleButton` instance:

ToggleButton toggleButton1 = new ToggleButton("Left");

This example creates a `ToggleButton` with the text `Left` on.

### Adding a ToggleButton to the Scene Graph ###

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

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

package com.jenkov.javafx.controls;
    
    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.ToggleButton;
    import javafx.scene.layout.HBox;
    import javafx.stage.Stage;
    
    
    public class ToggleButtonExperiments extends Application  {
    
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            primaryStage.setTitle("HBox Experiment 1");
    
    
            ToggleButton toggleButton1 = new ToggleButton("Left");
    
            HBox hbox = new HBox(toggleButton1);
    
    
            Scene scene = new Scene(hbox, 200, 100);
            primaryStage.setScene(scene);
            primaryStage.show();
    
        }
    
        public static void main(String[] args) {
            Application.launch(args);
        }
    }

The application resulting from running the above example code is illustrated in the following two screenshots. The first screenshot shows a `ToggleButton` which is not pressed, and the second screenshot shows the same `ToggleButton` pressed (selected, activated etc.):

![f580c0b707154aacb28527e22c6fe743.png][]![2381734ff1d14b91954279f509220a01.png][]

### ToggleButton Text ###

You can set or change the text of a JavaFX ToggleButton via its `setText()` method. Here is an example of changing the text of a JavaFX ToggleButton via `setText()`:

ToggleButton toggleButton = new ToggleButton("Toggle This!");
    toggleButton.setText("New Text");

### ToggleButton Font ###

You can set the font to use to render the button text of a JavaFX ToggleButton via its `setFont()` method. You can read more about creating fonts in my [JavaFX Fonts][] tutorial. Here is an example of setting the font of a JavaFX ToggleButton:

ToggleButton toggleButton = new ToggleButton("Toggle This!");
    Font arialFontBold36  = Font.font("Arial", FontWeight.BOLD, 36);
    toggleButton.setFont(arialFontBold36);

### Reading Selected State ###

The `ToggleButton` class has a method named `isSelected` which lets you determine if the `ToggleButton` is selected (pressed) or not. The `isSelected()` method returns a `boolean` with the value `true` if the `ToggleButton` is selected, and `false` if not. Here is an example:

boolean isSelected = toggleButton1.isSelected();

### ToggleGroup ###

You can group JavaFX `ToggleButton` instances into a `ToggleGroup`. A `ToggleGroup` allows at most one `ToggleButton` to be toggled (pressed) at any time. The `ToggleButton` instances in a `ToggleGroup` thus functions similarly to radio buttons.

Here is a JavaFX `ToggleGroup` example:

ToggleButton toggleButton1 = new ToggleButton("Left");
    ToggleButton toggleButton2 = new ToggleButton("Right");
    ToggleButton toggleButton3 = new ToggleButton("Up");
    ToggleButton toggleButton4 = new ToggleButton("Down");
    
    ToggleGroup toggleGroup = new ToggleGroup();
    
    toggleButton1.setToggleGroup(toggleGroup);
    toggleButton2.setToggleGroup(toggleGroup);
    toggleButton3.setToggleGroup(toggleGroup);
    toggleButton4.setToggleGroup(toggleGroup);

Here is a full example that adds the 4 `ToggleButton` instances to a `ToggleGroup`, and adds them to the scene graph too:

package com.jenkov.javafx.controls;
    
    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.ToggleButton;
    import javafx.scene.control.ToggleGroup;
    import javafx.scene.layout.HBox;
    import javafx.stage.Stage;
    
    
    public class ToggleButtonExperiments extends Application  {
    
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            primaryStage.setTitle("HBox Experiment 1");
    
    
            ToggleButton toggleButton1 = new ToggleButton("Left");
            ToggleButton toggleButton2 = new ToggleButton("Right");
            ToggleButton toggleButton3 = new ToggleButton("Up");
            ToggleButton toggleButton4 = new ToggleButton("Down");
    
            ToggleGroup toggleGroup = new ToggleGroup();
    
            toggleButton1.setToggleGroup(toggleGroup);
            toggleButton2.setToggleGroup(toggleGroup);
            toggleButton3.setToggleGroup(toggleGroup);
            toggleButton4.setToggleGroup(toggleGroup);
    
            HBox hbox = new HBox(toggleButton1, toggleButton2, toggleButton3, toggleButton4);
    
    
            Scene scene = new Scene(hbox, 200, 100);
            primaryStage.setScene(scene);
            primaryStage.show();
    
        }
    
        public static void main(String[] args) {
            Application.launch(args);
        }
    }

The resulting applications looks like this:

![32be70d2d3c846d584197df735ef8a23.png][]

### Reading Selected State of a ToggleGroup ###

You can read which `ToggleButton` of a `ToggleGroup` is selected (pressed) using the `getSelectedToggle()` method, like this:

ToggleButton selectedToggleButton =
            (ToggleButton) toggleGroup.getSelectedToggle();

If no `ToggleButton` is selected the `getSelectedToggle()` method returns `null` .

[f580c0b707154aacb28527e22c6fe743.png]: https://img-blog.csdnimg.cn/f580c0b707154aacb28527e22c6fe743.png
[2381734ff1d14b91954279f509220a01.png]: https://img-blog.csdnimg.cn/2381734ff1d14b91954279f509220a01.png
[JavaFX Fonts]: https://jenkov.com/tutorials/javafx/fonts.html
[32be70d2d3c846d584197df735ef8a23.png]: https://img-blog.csdnimg.cn/32be70d2d3c846d584197df735ef8a23.png