JavaFX TextArea

水深无声 2023-10-15 14:22 32阅读 0赞

A JavaFX TextArea control enables users of a JavaFX application to enter text spanning multiple lines, which can then be read by the application. The JavaFX TextArea control is represented by the class `javafx.scene.control.TextArea` .

### Creating a TextArea ###

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

TextArea textArea = new TextArea();

### Adding a TextArea to the Scene Graph ###

For a JavaFX `TextArea` to be visible the `TextArea` object must be added 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 `TextArea` to the scene graph:

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

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

![fb33319b38844ee9b90137d13ea90f2c.png][]

### Reading the Text of a TextArea ###

You can read the text entered into a `TextArea` via its `getText()` method. Here is an example of reading text of a JavaFX `TextArea` control via its `getText()` method:

String text = textArea.getText();

Here is a full example that shows a `TextArea` and a `Button` and which reads the text entered into the `TextArea` when the button is clicked:

package com.jenkov.javafx.controls;
    
    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.Button;
    import javafx.scene.control.TextArea;
    import javafx.scene.layout.VBox;
    import javafx.stage.Stage;
    
    public class TextAreaExperiments extends Application  {
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            primaryStage.setTitle("TextArea Experiment 1");
    
            TextArea textArea = new TextArea();
    
            Button button = new Button("Click to get text");
            button.setMinWidth(50);
    
            button.setOnAction(action -> {
                System.out.println(textArea.getText());
    
                textArea.setText("Clicked!");
            });
    
            VBox vbox = new VBox(textArea, button);
    
            Scene scene = new Scene(vbox, 200, 100);
            primaryStage.setScene(scene);
            primaryStage.show();
        }
    
        public static void main(String[] args) {
            Application.launch(args);
        }
    }

### Setting the Text of a TextArea ###

You can set the text of a `TextArea` control via its `setText()` method. Here is an example of setting the text of a `TextArea` control via `setText()` :

textArea.setText("New Text");

[fb33319b38844ee9b90137d13ea90f2c.png]: https://img-blog.csdnimg.cn/fb33319b38844ee9b90137d13ea90f2c.png