保存JavaFX快照时获取黑色图像
我设置了一个后台任务,在给定的面板/图表可见后等待几秒钟。这是通过在后台非GUI线程上运行保存JavaFX快照时获取黑色图像,java,javafx,save-image,Java,Javafx,Save Image,我设置了一个后台任务,在给定的面板/图表可见后等待几秒钟。这是通过在后台非GUI线程上运行sleep,然后在唤醒时运行 Platform.runLater 创建快照和映像 在保存图像的真正“操作”发生之前,我们可以看到窗口出现: 在渲染图像时,我们有一个任务使其休眠的背景代码。5000毫秒后,后台任务唤醒并启动Platform.runLater将场景/窗格/图表保存到文件中 import java.awt.Graphics2D; import java.awt.image.BufferedI
sleep
,然后在唤醒时运行
Platform.runLater
创建快照和映像
在保存图像的真正“操作”发生之前,我们可以看到窗口出现:
在渲染图像时,我们有一个任务
使其休眠的背景代码。5000毫秒后,后台任务唤醒并启动Platform.runLater
将场景/窗格/图表保存到文件中
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javafx.animation.PauseTransition;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.image.Image;
import javafx.scene.image.WritableImage;
import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.util.Duration;
import javax.imageio.ImageIO;
public class AutoSnapshot extends Application {
private static String fileName = "c:/temp/image.jpg";
private static Color backgroundColor = Color.WHITE;
@Override
public void start(Stage primaryStage) {
AnchorPane root = new AnchorPane();
// dummy chart
final NumberAxis xAxis = new NumberAxis();
final NumberAxis yAxis = new NumberAxis();
xAxis.setLabel("Number of Month");
final LineChart<Number, Number> lineChart = new LineChart<Number, Number>(xAxis, yAxis);
lineChart.setTitle("Stock Monitoring, 2010");
XYChart.Series series = new XYChart.Series();
series.setName("My portfolio");
series.getData().add(new XYChart.Data(1, 23));
series.getData().add(new XYChart.Data(2, 14));
series.getData().add(new XYChart.Data(3, 15));
series.getData().add(new XYChart.Data(4, 24));
lineChart.getData().add(series);
root.getChildren().add( lineChart);
Scene scene = new Scene(root, 800, 600, backgroundColor);
primaryStage.setScene(scene);
primaryStage.show();
Duration delay = Duration.seconds(5);
PauseTransition pt = new PauseTransition(delay);
pt.setOnFinished(e -> {
saveSnapshot(lineChart);
});
pt.play();
}
public static Image createImage(Node node) {
WritableImage wi;
SnapshotParameters parameters = new SnapshotParameters();
parameters.setFill(backgroundColor);
int imageWidth = (int) node.getBoundsInLocal().getWidth();
int imageHeight = (int) node.getBoundsInLocal().getHeight();
wi = new WritableImage(imageWidth, imageHeight);
node.snapshot(parameters, wi);
return wi;
}
private static void saveSnapshot(Node node) {
Image image = createImage(node);
// save image !!! has bug because of transparency (use approach below) !!!
// ImageIO.write(SwingFXUtils.fromFXImage( selectedImage.getImage(), null), "jpg", file);
// save image (without alpha)
BufferedImage bufImageARGB = SwingFXUtils.fromFXImage(image, null);
BufferedImage bufImageRGB = new BufferedImage(bufImageARGB.getWidth(), bufImageARGB.getHeight(), BufferedImage.OPAQUE);
Graphics2D graphics = bufImageRGB.createGraphics();
graphics.drawImage(bufImageARGB, 0, 0, null);
try {
ImageIO.write(bufImageRGB, "jpg", new File(fileName));
} catch (IOException e) {
e.printStackTrace();
}
graphics.dispose();
System.out.println( "Image saved: " + fileName);
}
public static void main(String[] args) {
launch(args);
}
}
以下是快照和图像代码:
所有这些都是通过提交到线程池的任务在后台线程上发生的
Thread.sleep(5000) // Wait for images to be rendered -
// they are visually confirmed to be available at about 1000 ms actually
javafx.application.Platform.runLater(new Runnable() {
override def run() = {
// val snapShot = chart.snapshot(null)
// val snapShot = scene.snapshot(null)
val snapShot = pane.snapshot(null,null)
ImageIO.write(SwingFXUtils.fromFXImage(snapShot, null),
"jpg", new File(fileName))
正如您所看到的(从注释掉的行中)-我对用于创建快照的对象感到困惑:已经尝试了以上三种方法:
- 图表
- 场面
- 窗格玻璃
结果始终是黑色图像。OOC我还尝试通过
snapshotParameters.setFill(Color.WHITE)
那没有效果
正确的程序是什么
更新我还尝试了回调
方法:
pane.snapshot( // Also tried scene and chart here ..
new Callback[SnapshotResult, Void]() {
override def call(result: SnapshotResult): Void = {
ImageIO.write(SwingFXUtils.fromFXImage(result.getImage, null),
"jpg", new File(fileName))
latch.countDown
null
}
},p,null)
同样-仍然是黑色图像 使用这种启发式是相当危险的。但是,您没有提供完整的MCVE。如果您想这样做,可以使用PauseTransition,快照任何节点,然后将图像保存到文件中
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javafx.animation.PauseTransition;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.image.Image;
import javafx.scene.image.WritableImage;
import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.util.Duration;
import javax.imageio.ImageIO;
public class AutoSnapshot extends Application {
private static String fileName = "c:/temp/image.jpg";
private static Color backgroundColor = Color.WHITE;
@Override
public void start(Stage primaryStage) {
AnchorPane root = new AnchorPane();
// dummy chart
final NumberAxis xAxis = new NumberAxis();
final NumberAxis yAxis = new NumberAxis();
xAxis.setLabel("Number of Month");
final LineChart<Number, Number> lineChart = new LineChart<Number, Number>(xAxis, yAxis);
lineChart.setTitle("Stock Monitoring, 2010");
XYChart.Series series = new XYChart.Series();
series.setName("My portfolio");
series.getData().add(new XYChart.Data(1, 23));
series.getData().add(new XYChart.Data(2, 14));
series.getData().add(new XYChart.Data(3, 15));
series.getData().add(new XYChart.Data(4, 24));
lineChart.getData().add(series);
root.getChildren().add( lineChart);
Scene scene = new Scene(root, 800, 600, backgroundColor);
primaryStage.setScene(scene);
primaryStage.show();
Duration delay = Duration.seconds(5);
PauseTransition pt = new PauseTransition(delay);
pt.setOnFinished(e -> {
saveSnapshot(lineChart);
});
pt.play();
}
public static Image createImage(Node node) {
WritableImage wi;
SnapshotParameters parameters = new SnapshotParameters();
parameters.setFill(backgroundColor);
int imageWidth = (int) node.getBoundsInLocal().getWidth();
int imageHeight = (int) node.getBoundsInLocal().getHeight();
wi = new WritableImage(imageWidth, imageHeight);
node.snapshot(parameters, wi);
return wi;
}
private static void saveSnapshot(Node node) {
Image image = createImage(node);
// save image !!! has bug because of transparency (use approach below) !!!
// ImageIO.write(SwingFXUtils.fromFXImage( selectedImage.getImage(), null), "jpg", file);
// save image (without alpha)
BufferedImage bufImageARGB = SwingFXUtils.fromFXImage(image, null);
BufferedImage bufImageRGB = new BufferedImage(bufImageARGB.getWidth(), bufImageARGB.getHeight(), BufferedImage.OPAQUE);
Graphics2D graphics = bufImageRGB.createGraphics();
graphics.drawImage(bufImageARGB, 0, 0, null);
try {
ImageIO.write(bufImageRGB, "jpg", new File(fileName));
} catch (IOException e) {
e.printStackTrace();
}
graphics.dispose();
System.out.println( "Image saved: " + fileName);
}
public static void main(String[] args) {
launch(args);
}
}
导入java.awt.Graphics2D;
导入java.awt.image.buffereImage;
导入java.io.File;
导入java.io.IOException;
导入javafx.animation.PauseTransition;
导入javafx.application.application;
导入javafx.embed.swing.SwingFXUtils;
导入javafx.scene.Node;
导入javafx.scene.scene;
导入javafx.scene.Snapshot参数;
导入javafx.scene.chart.LineChart;
导入javafx.scene.chart.NumberAxis;
导入javafx.scene.chart.XYChart;
导入javafx.scene.image.image;
导入javafx.scene.image.WritableImage;
导入javafx.scene.layout.ancorpane;
导入javafx.scene.paint.Color;
导入javafx.stage.stage;
导入javafx.util.Duration;
导入javax.imageio.imageio;
公共类AutoSnapshot扩展了应用程序{
私有静态字符串fileName=“c:/temp/image.jpg”;
私有静态颜色backgroundColor=Color.WHITE;
@凌驾
公共无效开始(阶段primaryStage){
锚烷根=新锚烷();
//虚拟图表
最终数字axis xAxis=新数字axis();
最终数字axis yAxis=新数字axis();
xAxis.setLabel(“月数”);
最终线形图线形图=新线形图(xAxis,yAxis);
线形图.setTitle(“库存监控,2010年”);
XYChart.Series系列=新的XYChart.Series();
series.setName(“我的投资组合”);
series.getData().add(新的XYChart.Data(1,23));
series.getData().add(新的XYChart.Data(2,14));
series.getData().add(新的XYChart.Data(3,15));
series.getData().add(新的XYChart.Data(4,24));
lineChart.getData().add(系列);
root.getChildren().add(折线图);
场景=新场景(根,800600,背景色);
初级阶段。场景(场景);
primaryStage.show();
持续时间延迟=持续时间。秒(5);
PauseTransition pt=新的PauseTransition(延迟);
零件设置完成(e->{
保存快照(折线图);
});
pt.play();
}
公共静态映像createImage(节点){
可写图像;
SnapshotParameters=新的SnapshotParameters();
参数设置填充(背景色);
int imageWidth=(int)node.getBoundsInLocal().getWidth();
int imageHeight=(int)node.getBoundsInLocal().getHeight();
wi=新的可写图像(图像宽度、图像高度);
节点快照(参数,wi);
返回wi;
}
私有静态void saveSnapshot(节点){
Image Image=createImage(节点);
//保存图像!!!由于透明度问题出现错误(使用下面的方法)!!!
//write(SwingFXUtils.fromFXImage(selectedImage.getImage(),null),“jpg”,文件);
//保存图像(不带alpha)
buffereImage bufImageARGB=SwingFXUtils.fromFXImage(image,null);
buffereImage bufImageRGB=新的buffereImage(bufImageRGB.getWidth(),bufImageRGB.getHeight(),buffereImage.不透明);
Graphics2D graphics=bufImageRGB.createGraphics();
graphics.drawImage(bufImageARGB,0,0,null);
试一试{
write(bufImageRGB,“jpg”,新文件(文件名));
}捕获(IOE异常){
e、 printStackTrace();
}
graphics.dispose();
System.out.println(“保存的图像:“+文件名”);
}
公共静态void main(字符串[]args){
发射(args);
}
}
毕竟。。答案是“jpg”根本不起作用。“png”格式工作正常。您的代码有以下内容:“保存图像!!!由于透明度而存在错误(使用下面的方法)”。注释掉的代码就是我目前使用的代码。我将首先替换为您的saveSnapshot。该代码只会为您提供错误的颜色,但不会提供黑色图像。我认为问题出在你的线程上。请尝试暂停转换。在替换saveSnapshot/createImage后,我确实看到了白色背景和一些图表。不透明不存在:是否应替换为BuffereImage.TYPE\u BYTE\u BINARY?顺便说一句,我将添加暂停转换。好吧,任何适合你的东西,尽管不透明应该存在。这是Java标准。我发布的代码对我来说很有用。顺便说一句,如果你想要透明度,你需要使用Color.TRANSPARENT作为快照填充参数。我正在向上投票,因为这很有帮助(尽管还有很长的路要走)。JDK8上的java.awt.buffereImage不具有不透明性。