JavaFX ImageView

本是古典何须时尚 2023-10-14 18:58 10阅读 0赞

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

### Creating an ImageView ###

You create an ImageView control instance by creating an instance of the `ImageView` class. The constructor of the `ImageView` class needs an instance of a `javafx.scene.image.Image` as parameter. The `Image` object represents the image to be displayed by the `ImageView` control.

Here is a JavaFX ImageView instantiation example:

FileInputStream input = new FileInputStream("resources/images/iconmonstr-home-6-48.png");
    Image image = new Image(input);
    ImageView imageView = new ImageView(image);

First a `FileInputStream` is created which points to the image file of the image to display.

Second an `Image` instance is created, passing the `FileInputStream` as parameter to the `Image` constructor. This way the `Image` class knows where to load the image file from.

Third an `ImageView` instance is created, passing the `Image` instance as parameter to the `ImageView` constructor.

### Adding an ImageView to the Scene Graph ###

To make the `ImageViewl` visible you must add it to the scene graph. This means adding it to a `Scene` object. Since `ImageView` is not a subclass of `javafx.scene.Parent` it cannot be added directly to the scene grahp. It must be nested inside another component, for instance a layout component.

Here is an example that attaches a JavaFX `ImageView` to the scene graph by nesting it inside a `HBox` layout component:

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

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

![f10d7c82b3bb4d708d7a7291ecbdd2c1.png][]

### ImageView in Labels and Buttons ###

It is possible to use an `ImageView` in both a JavaFX `Label` and Button. This will cause the `Label` and `Button` to display the `ImageView` to the left of the text in the `Label` or `Button`. See the texts about [JavaFX Label][] and [JavaFX Button][] for information about how to do that.

url: [JavaFX ImageView][]

[f10d7c82b3bb4d708d7a7291ecbdd2c1.png]: https://img-blog.csdnimg.cn/f10d7c82b3bb4d708d7a7291ecbdd2c1.png
[JavaFX Label]: https://jenkov.com/tutorials/javafx/label.html
[JavaFX Button]: https://jenkov.com/tutorials/javafx/button.html
[JavaFX ImageView]: https://jenkov.com/tutorials/javafx/imageview.html