java - 尝试将图像转换为 BufferedImage

Question

我正在为游戏编写 Java 代码，在创建健康栏时，我看到了一个异常，这让我非常困惑。代码和堆栈如下:

代码:

package com.teamanubiz.pixelhero;

import java.awt.Graphics;
import java.awt.Image;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import com.teamanubiz.gameapi.gfx.Sprite;

public class GUIRenderLayer {

  public void renderStatBar(GUIPosition pos, Graphics g, int health, int maxHealth, int mana, int maxMana) {

    Sprite healthBar = null;
    try {
        healthBar = new Sprite(ImageIO.read(new File("res\\gui\\bar.png")));
    } catch (IOException e2) {
        // TODO Auto-generated catch block
        e2.printStackTrace();
    }
    healthBar.crop(0, 0, 128, 32);
    healthBar.scale(256, 32);
    Sprite manaBar = null;
    try {
        manaBar = new Sprite(ImageIO.read(new File("res\\gui\\bar.png")));
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    manaBar.crop(0, 32, 128, 32);
    manaBar.scale(265, 16);
    Sprite temp = null;
    try {
        temp = new Sprite(ImageIO.read(new File("res\\gui\\bar.png")));
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    temp.crop(0, 64, 128, 32);
    temp.scale(256, 32);
    Sprite emptyHealth = new Sprite(temp.getCurrent());
    temp.scale(256, 16);
    Sprite emptyMana = new Sprite(temp.getCurrent());

    if (pos == GUIPosition.BOTTOM) {

      double percent_h = health / maxHealth;
      double percent_m = mana / maxMana;

      healthBar.crop(0, 0, (int) ((int) 256 * percent_h), 32);
      manaBar.crop(0, 0, (int) ((int) 256 * percent_m), 16);

      g.drawImage(emptyMana.getCurrent(), 100, 464, null);
      g.drawImage(emptyHealth.getCurrent(), 100, 432, null);
      g.drawImage(healthBar.getCurrent(), 100, 432, null);
      g.drawImage(manaBar.getCurrent(), 100, 464, null);

    }

  }

}

此类引用包含 Sprite 类的自定义库。由于某种原因，我试图在 Sprite.java 的以下方法中将 ToolkitImage 转换为 BufferedImage。

public void crop(int xOffset, int yOffset, int width, int height) {

    BufferedImage temp = (BufferedImage) source;

    temp = temp.getSubimage(xOffset, yOffset, width, height);

    source = temp;

}

变量source是Image的一个实例，它是Sprite.java中的一个字段

下面的堆栈声称我正在创建一个 ToolkitImage，尽管 new ImageIcon("res\\gui\\bar.png").getImage() 仅返回一个图像。我不会在代码中将 Image 转换为 ToolkitImage 。这使得它非常困惑。

堆栈跟踪:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: sun.awt.image.ToolkitImage cannot be cast to java.awt.image.BufferedImage
    at com.teamanubiz.gameapi.gfx.Sprite.crop(Sprite.java:48)
    at com.teamanubiz.pixelhero.GUIRenderLayer.renderStatBar(GUIRenderLayer.java:55)
    at com.teamanubiz.pixelhero.GameWindow.tick(GameWindow.java:14)
    at com.teamanubiz.gameapi.Display.paint(Display.java:95)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.access$1300(Unknown Source)
    at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: sun.awt.image.ToolkitImage cannot be cast to java.awt.image.BufferedImage
    at com.teamanubiz.gameapi.gfx.Sprite.crop(Sprite.java:48)
    at com.teamanubiz.pixelhero.GUIRenderLayer.renderStatBar(GUIRenderLayer.java:55)
    at com.teamanubiz.pixelhero.GameWindow.tick(GameWindow.java:14)
    at com.teamanubiz.gameapi.Display.paint(Display.java:95)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.access$1300(Unknown Source)
    at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: sun.awt.image.ToolkitImage cannot be cast to java.awt.image.BufferedImage
    at com.teamanubiz.gameapi.gfx.Sprite.crop(Sprite.java:48)
    at com.teamanubiz.pixelhero.GUIRenderLayer.renderStatBar(GUIRenderLayer.java:55)
    at com.teamanubiz.pixelhero.GameWindow.tick(GameWindow.java:14)
    at com.teamanubiz.gameapi.Display.paint(Display.java:95)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at javax.swing.RepaintManager$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.access$1300(Unknown Source)
    at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

BufferedImage 是 Image 的类型，但 Image 不是 BufferedImage 类型，您可以，例如例如，将 BufferedImage 转换为 Image。

不要使用 ImageIcon 加载图像，而是使用 ImageIO.read，它返回一个 BufferedImage

所以而不是...

 Sprite healthBar = new Sprite((Image)new ImageIcon("res\\gui\\bar.png").getImage()); // I Never Instatiated a ToolkitImage!!!!!!!!

注意:ImageIcon 将图像的实际加载委托(delegate)给 Toolkit 并将其包装在 Icon 界面中

使用类似...的东西

Sprite healthBar = new Sprite(ImageIO.read(new File("res\\gui\\bar.png")));