我试图写一个类打开一个外部程序,使一个阶段,说"请等待"与进度指示器,等待它完成,然后退出阶段。如果我使用primaryStage.showAndWait();
,程序工作,但如果我使用primaryStage.show();
,程序冻结,不会继续,直到类关闭。任何帮助都将非常感激。
package application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import java.io.IOException;
public class Wait {
public static void display(String prog, String progPath){
Stage primaryStage=new Stage();
primaryStage.setTitle("Please Wait");
primaryStage.setMinWidth(350);
ProgressIndicator indicator = new ProgressIndicator();
Label label1=new Label();
label1.setText("Please wait for "+prog+" to finish...");
HBox layout=new HBox(20);
layout.getChildren().addAll(indicator, label1);
layout.setAlignment(Pos.CENTER);
layout.setPadding(new Insets(20,20,20,20));
Scene scene =new Scene(layout);
primaryStage.setScene(scene);
primaryStage.show();// WHY U NO WORK?!?!?!?!
try {
Process p = Runtime.getRuntime().exec(progPath);
p.waitFor();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
primaryStage.close();
}
}
假设Wait.display()
正在FX应用程序线程上执行(这是必需的,因为它创建并显示Stage
),您的代码通过调用p.waitFor()
来阻塞FX应用程序线程。由于FX应用程序线程被阻塞,它不能做任何常规工作,如渲染UI或响应用户输入。
你需要在后台线程中管理进程。一旦后台进程完成,使用Task
将使在FX应用线程上执行代码变得容易:
public static void display(String prog, String progPath){
Stage primaryStage=new Stage();
primaryStage.setTitle("Please Wait");
primaryStage.setMinWidth(350);
ProgressIndicator indicator = new ProgressIndicator();
Label label1=new Label();
label1.setText("Please wait for "+prog+" to finish...");
HBox layout=new HBox(20);
layout.getChildren().addAll(indicator, label1);
layout.setAlignment(Pos.CENTER);
layout.setPadding(new Insets(20,20,20,20));
Scene scene =new Scene(layout);
primaryStage.setScene(scene);
primaryStage.show();
Task<Void> task = new Task<Void>() {
@Override
public Void call() throws Exception {
try {
Process p = Runtime.getRuntime().exec(progPath);
p.waitFor();
} catch (IOException | InterruptedException e) {
e.printStackTrace();
}
return null;
};
task.setOnSucceeded(e -> primaryStage.close());
Thread thread = new Thread(task);
thread.setDaemon(true); // thread will not prevent application from exiting
thread.start();
}