backgroundimage.java

精通Java网络编程代码全部

//源程序清单
import java.awt.*;
import java. applet.*;
public class BackgroundImage extends Applet //继承Applet
{
	Image picture;
	boolean ImageLoaded=false;
	public void init()
	{
		picture=getImage(getCodeBase(),"Image.gif"); //装载图像
		Image offScreenImage=createImage(size().width,size().height);
		//用方法createImage创建Image对象
		Graphics offScreenGC=offScreenImage.getGraphics(); //获取Graphics对象
		offScreenGC.drawImage(picture,0,0,this); //显示非屏幕图像
		ImageLoaded=true;
	}
	public void paint(Graphics g)
	{
		if(ImageLoaded)
		{
			g.drawImage(picture,0,0,null); //显示图像，第四参数为null,不是this
			showStatus("Done");
		}
		else
			showStatus("Loading image");
	}
	public boolean imageUpdate(Image img,int infoflags,int x,int y,int w,int h)
	{
		if(infoflags==ALLBITS)
		{
			ImageLoaded=true;
			repaint();
			return false;
		}
		else
			return true;
	}
}