淡化过渡不透明度调节器

时间:2018-05-07 07:18:53

标签: java javafx slider opacity

此代码的目的是从filechooser中选择一个图像,将该图像加载到ImageView中,并使用一个滑块来调整该图像的不透明度。

我目前正试图弄清楚我的代码有什么问题。我正在尝试为学校的作业完成这个程序,但我想我错过了一行代码。如果有人能解释我的错误是什么,那将非常感激。

package opacityadjuster;

import javafx.application.Application;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.animation.FadeTransition;
import javafx.embed.swing.SwingFXUtils;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Slider;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.VBox;
import javafx.stage.FileChooser;
import javafx.stage.Stage;

public class OpacityAdjuster extends Application{   

ImageView myImageView;

public static void main(String[] args){
    launch(args);
}     

@Override
public void start(Stage primaryStage){

  final double MIN = 0.0, MAX = 1.0, INITIAL = .50;
  final double MAJOR_TICK_UNIT = .1;
  final int MINOR_TICK_COUNT = 1;
  final double SLIDER_WIDTH = 300.0;

  Button button = new Button("Search for Image");
  Slider slider = new Slider(MIN, MAX, INITIAL);
  slider.setMajorTickUnit(MAJOR_TICK_UNIT);
  slider.setMinorTickCount(MINOR_TICK_COUNT);
  slider.setShowTickMarks(true);
  slider.setShowTickLabels(true);
  slider.setSnapToTicks(true);
  slider.setPrefWidth(SLIDER_WIDTH);

  button.setOnAction(e ->
  {
    FileChooser fileChooser = new FileChooser();

    FileChooser.ExtensionFilter extFilterJPG = 
        new FileChooser.ExtensionFilter("JPG files (*.JPG)", "*.JPG");
    FileChooser.ExtensionFilter extFilterjpg = 
        new FileChooser.ExtensionFilter("jpg files (*.jpg)", "*.jpg");
    FileChooser.ExtensionFilter extFilterPNG = 
        new FileChooser.ExtensionFilter("PNG files (*.PNG)", "*.PNG");
    FileChooser.ExtensionFilter extFilterpng = 
        new FileChooser.ExtensionFilter("png files (*.png)", "*.png");
    fileChooser.getExtensionFilters()
        .addAll(extFilterJPG, extFilterjpg, extFilterPNG, extFilterpng);

    File file = fileChooser.showOpenDialog(null);


       try {BufferedImage bufferedImage = ImageIO.read(file);
            Image image = SwingFXUtils.toFXImage(bufferedImage, null);
            myImageView.setImage(image);
       } 
       catch (IOException ex) {

        Logger.getLogger(OpacityAdjuster.class.getName()).log(Level.SEVERE, null, ex);
        }
    });

    FadeTransition ft = new FadeTransition();


    slider.valueProperty().addListener((observable, oldvalue, newvalue) ->{
           ft.setFromValue(oldvalue.doubleValue());
           ft.setToValue(newvalue.doubleValue());
           ft.play();
    });

    myImageView = new ImageView();  
    myImageView.setFitWidth(500);
    myImageView.setPreserveRatio(true);

    VBox vBox = new VBox(10);
    vBox.getChildren().addAll(button, slider, myImageView);
    vBox.setAlignment(Pos.TOP_CENTER);
    Scene scene = new Scene(vBox, 800, 800);

    primaryStage.setTitle("Opacity Adjuster");
    primaryStage.setScene(scene);
    primaryStage.show();

    }
 }

这就是我所做的。我读过我的书,问同学,我的教授,Reddit,甚至用Google搜索出来的问题,正好寻找我遗失的最后一部分。

1 个答案:

答案 0 :(得分:0)

您的代码几乎是完美的。你必须建立一种关系"在ImageView和FadeTransition之间,代码变得完美。如下更改您的代码,它们将完美运作

...
myImageView = new ImageView();  
myImageView.setFitWidth(500);
myImageView.setPreserveRatio(true);

button.setOnAction(e ->
{
  ...
});

FadeTransition ft = new FadeTransition(Duration.millis(1000), myImageView);

enter image description here