JavaFX 图像错误 [重复]

Question

我正在尝试制作一个简单的程序，它随机选择 1 到 52 之间的一个数字，并根据该数字抽一张牌。该卡片将由 JavaFX 显示。但是，每当我运行任何东西时，都会遇到一大堆错误。

到目前为止，我的主要想法是我的项目找不到图像。我创建了一个名为“resources”的文件夹，它们存储在那里，并直接在桌面上的文件夹中引用它们。还是没有运气。

代码如下：

(Imports removed for brevity)...

 public class Draw5 extends Application {
  @Override // Override the start method in the Application class
  public void start(Stage primaryStage) throws IOException {
    // Create a list of card numbers
    ArrayList<Integer> cards = getCards();
    // Create a HBox pane
    HBox pane = new HBox(5);
    pane.setPadding(new Insets(5, 5, 5, 5));

    // Add nodes to pane
    for (int i = 0; i < 5; i++) {

        pane.getChildren().add(new ImageView(new Image("C:\\Users\\Matthew\\Desktop\\card\\" +
                cards.get(i) + ".png")));

    }

    // Create a scene and place it in the stage
    Scene scene = new Scene(pane);
    primaryStage.setTitle("Exercise_14_03"); // Set the stage title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage
}

/** Returns a list with numbers 1-52 stored in random order */
private ArrayList<Integer> getCards() {
    ArrayList<Integer> cards = new ArrayList<>();
    for (int i = 0; i < 52; i++) {
        cards.add(i + 1);
    }
    java.util.Collections.shuffle(cards);
    return cards;
}


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

}

就像我说的，我觉得这个项目找不到卡片的 52 个 .png 图像，这很有趣。如果有人有任何建议，请告诉我。

为了记录，卡片是随机选择的，因此为什么 "cards.get(i) + ".png" "

这是我在启动时遇到的错误：

Exception in Application start method
Exception in thread "main" java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)


Caused by: java.lang.RuntimeException: Exception in Application start method
 at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
 at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(Unknown Source)
 at java.base/java.lang.Thread.run(Unknown Source)



Caused by: java.lang.IllegalArgumentException: Invalid URL: unknown protocol: c
at javafx.graphics/javafx.scene.image.Image.validateUrl(Unknown Source)
at javafx.graphics/javafx.scene.image.Image.<init>(Unknown Source)
at thibodeau14.Draw5.start(Draw5.java:31)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(Unknown Source)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(Unknown Source)
... 1 more
Caused by: java.net.MalformedURLException: unknown protocol: c
at java.base/java.net.URL.<init>(Unknown Source)
at java.base/java.net.URL.<init>(Unknown Source)
at java.base/java.net.URL.<init>(Unknown Source)
... 12 more

Answer 1

Image 类构造函数需要一个表示 URL 的字符串，当用一个用于文件的字符串表示 URL 时，将“file///”添加到 URL。

所以这个：

pane.getChildren().add(new ImageView(new Image("C:\\Users\\Matthew\\Desktop\\card\\" +
               cards.get(i) + ".png")));

变成：

pane.getChildren().add(new ImageView(new 
Image("file:\\\C:\\Users\\Matthew\\Desktop\\card\\" +
                cards.get(i) + ".png")));`