颜色 – JavaFX ProgressBar：如何改变栏颜色？

您的问题中的代码应显示两个不同的彩色进度条,事实上它不是JavaFX css处理系统中的错误.在这里记录运行时项目的错误：http://javafx-jira.kenai.com.

作为解决方法,而不是在进度条上调用setStyle,定义用于对样式表中的进度条进行颜色的重音颜色,并将样式类添加到进度条.然后,您可以在同一应用程序中创建多个进度条,全部具有不同的颜色.

正如Uluk指出的那样,您可以使用JavaFX 2.2 caspian.css与JavaFX 2 css reference guide和JavaFX 2 css tutorial一起来确定如何对事物进行风格化.

这里是一些基于这些引用中的信息自定义进度条的示例代码.

示例css：

/** progress.css
    place in same directory as 
    ColoredProgressBarStyleSheet.java or SimpleColoredProgressBar.java
    ensure build system copies the css file to the build output path */

.root { -fx-background-color: cornsilk; -fx-padding: 15; }

.progress-bar { -fx-box-border: goldenrod; }

.green-bar  { -fx-accent: green;  }
.yellow-bar { -fx-accent: yellow; }
.orange-bar { -fx-accent: orange; }
.red-bar    { -fx-accent: red;    }

简单示例程序：

import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

// shows multiple progress bars drawn in different colors.
public class SimpleColoredProgressBar extends Application {
     public static void main(String[] args) { launch(args); }

     @Override public void start(Stage stage) {
         final VBox layout = new VBox(10);
         layout.setAlignment(Pos.CENTER);
         layout.getChildren().setAll(
             new ColoredProgressBar("red-bar",0.2),new ColoredProgressBar("orange-bar",0.4),new ColoredProgressBar("yellow-bar",0.6),new ColoredProgressBar("green-bar",0.8)
         );
         layout.getStylesheets().add(getClass().getResource("progress.css").toExternalForm());
         stage.setScene(new Scene(layout));
         stage.show();
    }

    class ColoredProgressBar extends ProgressBar {
        ColoredProgressBar(String styleClass,double progress) {
            super(progress);
            getStyleClass().add(styleClass);
        }
    }
}

简单的示例程序输出：

更复杂的示例程序与单个动画进度条,根据进度量动态地更改颜色：

import javafx.animation.*;
import javafx.application.Application;
import javafx.beans.value.*;
import javafx.event.*;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Duration;

// shows a progress bar whose bar changes color depending on the amount of progress.
public class ColoredProgressBarStyleSheet extends Application {
  public static void main(String[] args) { launch(args); }

  private static final String RED_BAR    = "red-bar";
  private static final String YELLOW_BAR = "yellow-bar";
  private static final String ORANGE_BAR = "orange-bar";
  private static final String GREEN_BAR  = "green-bar";
  private static final String[] barColorStyleClasses = { RED_BAR,ORANGE_BAR,YELLOW_BAR,GREEN_BAR };

  @Override public void start(Stage stage) {
    final ProgressBar bar = new ProgressBar();

    final Timeline timeline = new Timeline(
      new KeyFrame(Duration.millis(0),new KeyValue(bar.progressProperty(),0)),new KeyFrame(Duration.millis(3000),1))
    );

    Button reset = new Button("Reset");
    reset.setOnAction(new EventHandler<ActionEvent>() {
      @Override public void handle(ActionEvent event) {
        timeline.playFromStart();
      }
    });

    bar.progressProperty().addListener(new ChangeListener<Number>() {
      @Override public void changed(ObservableValue<? extends Number> observable,Number oldValue,Number newValue) {
        double progress = newValue == null ? 0 : newValue.doubleValue();
        if (progress < 0.2) {
          setBarStyleClass(bar,RED_BAR);
        } else if (progress < 0.4) {
          setBarStyleClass(bar,ORANGE_BAR);
        } else if (progress < 0.6) {
          setBarStyleClass(bar,YELLOW_BAR);
        } else {
          setBarStyleClass(bar,GREEN_BAR);
        }
      }

      private void setBarStyleClass(ProgressBar bar,String barStyleClass) {
        bar.getStyleClass().removeAll(barColorStyleClasses);
        bar.getStyleClass().add(barStyleClass);
      }
    });    

    final VBox layout = new VBox(10);
    layout.setAlignment(Pos.CENTER);
    layout.getChildren().setAll(bar,reset);
    layout.getStylesheets().add(getClass().getResource("progress.css").toExternalForm());
    stage.setScene(new Scene(layout));
    stage.show();

    timeline.play();
  }    
}

更复杂的示例程序输出：