主类是在外国网站上看的，忘了是哪个网站了。直接上主类的代码
package com.doll.decodegif;import net.rim.device.api.ui.UiApplication;import net.rim.device.api.ui.XYRect;import net.rim.device.api.system.GIFEncodedImage;import net.rim.device.api.ui.Graphics;import net.rim.device.api.ui.component.BitmapField;//A field that displays an animated GIF.public class AnimatedGIFField extends BitmapField { private GIFEncodedImage _image; //The image to draw. private int _currentFrame; //The current frame in the animation sequence. private int _width; //The width of the image (background frame). private int _height; //The height of the image (background frame). private AnimatorThread _animatorThread; public AnimatedGIFField(GIFEncodedImage image) { this(image, 0); } public AnimatedGIFField(GIFEncodedImage image, long style) { //Call super to setup the field with the specified style. //The image is passed in as well for the field to configure its required size. super(image.getBitmap(), style); //Store the image and it's dimensions. _image = image; _width = image.getWidth(); _height = image.getHeight(); //Start the animation thread. _animatorThread = new AnimatorThread(this); _animatorThread.start(); } protected void paint(Graphics graphics) { //Call super.paint. This will draw the first background frame and handle any required focus drawing. super.paint(graphics); graphics.clear(this.getExtent()); //Don't redraw the background if this is the first frame. if (true) { //Draw the animation frame. graphics.drawImage(_image.getFrameLeft(_currentFrame), _image.getFrameTop(_currentFrame), _image.getFrameWidth(_currentFrame), _image.getFrameHeight(_currentFrame), _image, _currentFrame, 0, 0); } } //Stop the animation thread when the screen the field is on is //popped off of the display stack. protected void onUndisplay() { _animatorThread.stop(); super.onUndisplay(); } //A thread to handle the animation. private class AnimatorThread extends Thread { private AnimatedGIFField _theField; private boolean _keepGoing = true; private int _totalFrames; //The total number of frames in the image. private int _loopCount; //The number of times the animation has looped (completed). private int _totalLoops; //The number of times the animation should loop (set in the image). public AnimatorThread(AnimatedGIFField theField) { _theField = theField; _totalFrames = _image.getFrameCount(); _totalLoops = _image.getIterations(); } public synchronized void stop() { _keepGoing = false; } public void run() { while(_keepGoing) { //Invalidate the field so that it is redrawn. UiApplication.getUiApplication().invokeAndWait(new Runnable() { public void run() { //UiApplication.getUiApplication().getActiveScreen().invalidate(); _theField.invalidate(); } }); try { //Sleep for the current frame delay before the next frame is drawn. sleep(_image.getFrameDelay(_currentFrame) * 10); } catch (InterruptedException iex) {} //Couldn't sleep. //Increment the frame. ++_currentFrame; if (_currentFrame == _totalFrames) { //Reset back to frame 0 if we have reached the end. _currentFrame = 0; ++_loopCount; //Check if the animation should continue. if (_loopCount == _totalLoops) { _keepGoing = false; } } } } }}附件里面是解析GIF图片的一个Demo工程 （这是在Eclipse上的 在BB自己的IDE里面我也测试过了）