这些代码段中的一个有效,而另一个无效,但我不知道为什么。我试过调试一个无效的程序。代码的本质是相同的,我将其复制粘贴。可行的程序来自一个稍大的程序,该程序最初显示两个阶段。教授希望我们扩展原始程序的一部分,因此我认为最好创建一个新项目,以使其更易于阅读和上传。问题是新的不起作用。
This One Works
***int num1 = (int) (Math.random()*61);
int num2 = (int) (Math.random()*61);
int num3 = (int) (Math.random()*61);
Stage Tiles = new Stage();
Tiles.setTitle("Tiles");
FlowPane tilePane = new FlowPane();
System.out.println(num1 +" " + num2 + " " + num3);
ImageView image1 = new ImageView(String.valueOf(num1)+".png");
ImageView image2 = new ImageView(String.valueOf(num2)+".png");
ImageView image3 = new ImageView(String.valueOf(num3)+".png");
tilePane.getChildren().addAll(image1,image2,image3);
Scene secondScene = new Scene(tilePane);
Tiles.setScene(secondScene);
Tiles.show();
} ***
This One Does Not Work
public class Case_lab6a extends Application
{@Override
public void start(Stage main)
{
int num1 = (int) (Math.random()*61);
int num2 = (int) (Math.random()*61);
int num3 = (int) (Math.random()*61);
main.setTitle("Tiles v2");
FlowPane tilePane = new FlowPane();
System.out.println(num1 +" " + num2 + " " + num3);
ImageView image1 = new ImageView(String.valueOf(num1)+".png");
ImageView image2 = new ImageView(String.valueOf(num2)+".png");
ImageView image3 = new ImageView(String.valueOf(num3)+".png");
tilePane.getChildren().addAll(image1,image2,image3);
Scene secondScene = new Scene(tilePane);
main.setScene(secondScene);
main.show();
}
基于错误,我得到此问题与编译器无法识别图像有关。我知道我的结构方式很奇怪,并且可能有更好的方法,但是我有61张图像全部存储在src文件中。
编辑:非功能性细分市场的进口:
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
该工作部门的进口:
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.ImageView;
import static javafx.scene.layout.BackgroundPosition.CENTER;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
非功能程序的输出:
23 35 22
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$155(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: Invalid URL: Invalid URL or resource not found
at javafx.scene.image.Image.validateUrl(Image.java:1118)
at javafx.scene.image.Image.<init>(Image.java:620)
at javafx.scene.image.ImageView.<init>(ImageView.java:166)
at lab6a.Case_lab6a.start(Case_lab6a.java:35)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
... 1 more
Caused by: java.lang.IllegalArgumentException: Invalid URL or resource not found
at javafx.scene.image.Image.validateUrl(Image.java:1110)
... 12 more
Exception running application lab6a.Case_lab6a
C:\Users\Kindness\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 1 second)
Stage Tiles = new Stage();
[而另一个(您说的那个不起作用)希望您在调用Stage
方法时传递start()
对象。
[Aside:Tiles
变量应为tiles
以遵循Java命名约定。类名以大写字母开头,变量应为camelCase。]您说错误与图像有关。包括确切的错误消息(以及完整的堆栈跟踪,如果可能)将对您有所帮助。
您应注意的一件事是,当您使用
Math.random()
时,它可能会返回0
。您的图片编号从0到60?如果没有,也许它会时不时地(随机)找不到图像文件。顺便说一句,要生成随机整数,最好使用:
Random rand = new Random(); int num1 = rand.nextInt(61); int num2 = rand.nextInt(61); int num3 = rand.nextInt(61);
此外,您可以将String.valueOf(num1)+".png"
简化为num1 + ".png"
。整数附加到字符串后会自动转换为字符串。您已经在System.out.println(num1 + " " + num2 + " " + num3)
行中完成了此操作。