android中播放gif動畫之三

之前寫了些簡單的類基本可以實現gif的播放，主要是使用的Movie類來解決的。今天無意中在網上看到有個開源小項目GifView可以用來解析播放GIF，名字居然跟我寫的控件一樣，呵呵，看了源碼，實現方式跟我的有很大區別，而且他提供了更多接口，可以傳入GIF圖片的資源ID，對應的流，或者二進制byte[]數組，還提供設置gif在解碼過程中的顯示方式，主要有三種方式：邊解析邊顯示、解析完再顯示、解析過程中顯示第一幀。它還提供設置顯示的圖片的大小等等。確實功能強大許多，下面直接上項目源碼：

源碼：

GifView：

package com.ant.liao;

import java.io.InputStream;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

/**
 * GifView

 * 本類可以顯示一個gif動畫，其使用方法和android的其它view（如imageview)一樣。

 * 如果要顯示的gif太大，會出現OOM的問題。
 * 
 * @author liao
 * 
 */
public class GifView extends View implements GifAction {

	/** gif解碼器 */
	private GifDecoder gifDecoder = null;
	/** 當前要畫的幀的圖 */
	private Bitmap currentImage = null;

	private boolean isRun = true;

	private boolean pause = false;

	private int showWidth = -1;
	private int showHeight = -1;
	private Rect rect = null;

	private DrawThread drawThread = null;

	private GifImageType animationType = GifImageType.SYNC_DECODER;

	/**
	 * 解碼過程中，Gif動畫顯示的方式

	 * 如果圖片較大，那麼解碼過程會比較長，這個解碼過程中，gif如何顯示
	 * 
	 * @author liao
	 * 
	 */
	public enum GifImageType {
		/**
		 * 在解碼過程中，不顯示圖片，直到解碼全部成功後，再顯示
		 */
		WAIT_FINISH(0),
		/**
		 * 和解碼過程同步，解碼進行到哪裡，圖片顯示到哪裡
		 */
		SYNC_DECODER(1),
		/**
		 * 在解碼過程中，只顯示第一幀圖片
		 */
		COVER(2);

		GifImageType(int i) {
			nativeInt = i;
		}

		final int nativeInt;
	}

	public GifView(Context context) {
		super(context);

	}

	public GifView(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public GifView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

	}

	/**
	 * 設置圖片，並開始解碼
	 * 
	 * @param gif
	 *            要設置的圖片
	 */
	private void setGifDecoderImage(byte[] gif) {
		if (gifDecoder != null) {
			gifDecoder.free();
			gifDecoder = null;
		}
		gifDecoder = new GifDecoder(gif, this);
		gifDecoder.start();
	}

	/**
	 * 設置圖片，開始解碼
	 * 
	 * @param is
	 *            要設置的圖片
	 */
	private void setGifDecoderImage(InputStream is) {
		if (gifDecoder != null) {
			gifDecoder.free();
			gifDecoder = null;
		}
		gifDecoder = new GifDecoder(is, this);
		gifDecoder.start();
	}

	/**
	 * 以字節數據形式設置gif圖片
	 * 
	 * @param gif
	 *            圖片
	 */
	public void setGifImage(byte[] gif) {
		setGifDecoderImage(gif);
	}

	/**
	 * 以字節流形式設置gif圖片
	 * 
	 * @param is
	 *            圖片
	 */
	public void setGifImage(InputStream is) {
		setGifDecoderImage(is);
	}

	/**
	 * 以資源形式設置gif圖片
	 * 
	 * @param resId
	 *            gif圖片的資源ID
	 */
	public void setGifImage(int resId) {
		Resources r = this.getResources();
		InputStream is = r.openRawResource(resId);
		setGifDecoderImage(is);
	}

	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		if (gifDecoder == null)
			return;
		if (currentImage == null) {
			currentImage = gifDecoder.getImage();
		}
		if (currentImage == null) {
			return;
		}
		int saveCount = canvas.getSaveCount();
		canvas.save();
		canvas.translate(getPaddingLeft(), getPaddingTop());
		if (showWidth == -1) {
			canvas.drawBitmap(currentImage, 0, 0, null);
		} else {
			canvas.drawBitmap(currentImage, null, rect, null);
		}
		canvas.restoreToCount(saveCount);
	}

	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		int pleft = getPaddingLeft();
		int pright = getPaddingRight();
		int ptop = getPaddingTop();
		int pbottom = getPaddingBottom();

		int widthSize;
		int heightSize;

		int w;
		int h;

		if (gifDecoder == null) {
			w = 1;
			h = 1;
		} else {
			w = gifDecoder.width;
			h = gifDecoder.height;
		}

		w += pleft + pright;
		h += ptop + pbottom;

		w = Math.max(w, getSuggestedMinimumWidth());
		h = Math.max(h, getSuggestedMinimumHeight());

		widthSize = resolveSize(w, widthMeasureSpec);
		heightSize = resolveSize(h, heightMeasureSpec);

		setMeasuredDimension(widthSize, heightSize);
	}

	/**
	 * 只顯示第一幀圖片

	 * 調用本方法後，gif不會顯示動畫，只會顯示gif的第一幀圖
	 */
	public void showCover() {
		if (gifDecoder == null)
			return;
		pause = true;
		currentImage = gifDecoder.getImage();
		invalidate();
	}

	/**
	 * 繼續顯示動畫

	 * 本方法在調用showCover後，會讓動畫繼續顯示，如果沒有調用showCover方法，則沒有任何效果
	 */
	public void showAnimation() {
		if (pause) {
			pause = false;
		}
	}

	/**
	 * 設置gif在解碼過程中的顯示方式

	 * 本方法只能在setGifImage方法之前設置，否則設置無效
	 * 
	 * @param type
	 *            顯示方式
	 */
	public void setGifImageType(GifImageType type) {
		if (gifDecoder == null)
			animationType = type;
	}

	/**
	 * 設置要顯示的圖片的大小

	 * 當設置了圖片大小 之後，會按照設置的大小來顯示gif（按設置後的大小來進行拉伸或壓縮）
	 * 
	 * @param width
	 *            要顯示的圖片寬
	 * @param height
	 *            要顯示的圖片高
	 */
	public void setShowDimension(int width, int height) {
		if (width > 0 && height > 0) {
			showWidth = width;
			showHeight = height;
			rect = new Rect();
			rect.left = 0;
			rect.top = 0;
			rect.right = width;
			rect.bottom = height;
		}
	}

	public void parseOk(boolean parseStatus, int frameIndex) {
		if (parseStatus) {
			if (gifDecoder != null) {
				switch (animationType) {
				case WAIT_FINISH:
					if (frameIndex == -1) {
						if (gifDecoder.getFrameCount() > 1) { // 當幀數大於1時，啟動動畫線程
							DrawThread dt = new DrawThread();
							dt.start();
						} else {
							reDraw();
						}
					}
					break;
				case COVER:
					if (frameIndex == 1) {
						currentImage = gifDecoder.getImage();
						reDraw();
					} else if (frameIndex == -1) {
						if (gifDecoder.getFrameCount() > 1) {
							if (drawThread == null) {
								drawThread = new DrawThread();
								drawThread.start();
							}
						} else {
							reDraw();
						}
					}
					break;
				case SYNC_DECODER:
					if (frameIndex == 1) {
						currentImage = gifDecoder.getImage();
						reDraw();
					} else if (frameIndex == -1) {
						reDraw();
					} else {
						if (drawThread == null) {
							drawThread = new DrawThread();
							drawThread.start();
						}
					}
					break;
				}

			} else {
				Log.e(gif, parse error);
			}

		}
	}

	private void reDraw() {
		if (redrawHandler != null) {
			Message msg = redrawHandler.obtainMessage();
			redrawHandler.sendMessage(msg);
		}
	}

	private Handler redrawHandler = new Handler() {
		public void handleMessage(Message msg) {
			invalidate();
		}
	};

	/**
	 * 動畫線程
	 * 
	 * @author liao
	 * 
	 */
	private class DrawThread extends Thread {
		public void run() {
			if (gifDecoder == null) {
				return;
			}
			while (isRun) {
				if (pause == false) {
					// if(gifDecoder.parseOk()){
					GifFrame frame = gifDecoder.next();
					currentImage = frame.image;
					long sp = frame.delay;
					if (redrawHandler != null) {
						Message msg = redrawHandler.obtainMessage();
						redrawHandler.sendMessage(msg);
						SystemClock.sleep(sp);
					} else {
						break;
					}
					// }else{
					// currentImage = gifDecoder.getImage();
					// break;
					// }
				} else {
					SystemClock.sleep(10);
				}
			}
		}
	}

}

GifFrame：

package com.ant.liao;

import android.graphics.Bitmap;

public class GifFrame {
	/**
	 * 構造函數
	 * 
	 * @param im
	 *            圖片
	 * @param del
	 *            延時
	 */
	public GifFrame(Bitmap im, int del) {
		image = im;
		delay = del;
	}

	/** 圖片 */
	public Bitmap image;
	/** 延時 */
	public int delay;
	/** 下一幀 */
	public GifFrame nextFrame = null;
}

GifDecoder：

package com.ant.liao;

import java.io.ByteArrayInputStream;
import java.io.InputStream;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;

public class GifDecoder extends Thread {

	/** 狀態：正在解碼中 */
	public static final int STATUS_PARSING = 0;
	/** 狀態：圖片格式錯誤 */
	public static final int STATUS_FORMAT_ERROR = 1;
	/** 狀態：打開失敗 */
	public static final int STATUS_OPEN_ERROR = 2;
	/** 狀態：解碼成功 */
	public static final int STATUS_FINISH = -1;

	private InputStream in;
	private int status;

	public int width; // full image width
	public int height; // full image height
	private boolean gctFlag; // global color table used
	private int gctSize; // size of global color table
	private int loopCount = 1; // iterations; 0 = repeat forever

	private int[] gct; // global color table
	private int[] lct; // local color table
	private int[] act; // active color table

	private int bgIndex; // background color index
	private int bgColor; // background color
	private int lastBgColor; // previous bg color
	private int pixelAspect; // pixel aspect ratio

	private boolean lctFlag; // local color table flag
	private boolean interlace; // interlace flag
	private int lctSize; // local color table size

	private int ix, iy, iw, ih; // current image rectangle
	private int lrx, lry, lrw, lrh;
	private Bitmap image; // current frame
	private Bitmap lastImage; // previous frame
	private GifFrame currentFrame = null;

	private boolean isShow = false;

	private byte[] block = new byte[256]; // current data block
	private int blockSize = 0; // block size

	// last graphic control extension info
	private int dispose = 0;
	// 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
	private int lastDispose = 0;
	private boolean transparency = false; // use transparent color
	private int delay = 0; // delay in milliseconds
	private int transIndex; // transparent color index

	private static final int MaxStackSize = 4096;
	// max decoder pixel stack size

	// LZW decoder working arrays
	private short[] prefix;
	private byte[] suffix;
	private byte[] pixelStack;
	private byte[] pixels;

	private GifFrame gifFrame; // frames read from current file
	private int frameCount;

	private GifAction action = null;

	private byte[] gifData = null;

	public GifDecoder(byte[] data, GifAction act) {
		gifData = data;
		action = act;
	}

	public GifDecoder(InputStream is, GifAction act) {
		in = is;
		action = act;
	}

	public void run() {
		if (in != null) {
			readStream();
		} else if (gifData != null) {
			readByte();
		}
	}

	/**
	 * 釋放資源
	 */
	public void free() {
		GifFrame fg = gifFrame;
		while (fg != null) {
			fg.image = null;
			fg = null;
			gifFrame = gifFrame.nextFrame;
			fg = gifFrame;
		}
		if (in != null) {
			try {
				in.close();
			} catch (Exception ex) {
			}
			in = null;
		}
		gifData = null;
	}

	/**
	 * 當前狀態
	 * 
	 * @return
	 */
	public int getStatus() {
		return status;
	}

	/**
	 * 解碼是否成功，成功返回true
	 * 
	 * @return 成功返回true，否則返回false
	 */
	public boolean parseOk() {
		return status == STATUS_FINISH;
	}

	/**
	 * 取某幀的延時時間
	 * 
	 * @param n
	 *            第幾幀
	 * @return 延時時間，毫秒
	 */
	public int getDelay(int n) {
		delay = -1;
		if ((n >= 0) && (n < frameCount)) {
			// delay = ((GifFrame) frames.elementAt(n)).delay;
			GifFrame f = getFrame(n);
			if (f != null)
				delay = f.delay;
		}
		return delay;
	}

	/**
	 * 取所有幀的延時時間
	 * 
	 * @return
	 */
	public int[] getDelays() {
		GifFrame f = gifFrame;
		int[] d = new int[frameCount];
		int i = 0;
		while (f != null && i < frameCount) {
			d[i] = f.delay;
			f = f.nextFrame;
			i++;
		}
		return d;
	}

	/**
	 * 取總幀 數
	 * 
	 * @return 圖片的總幀數
	 */
	public int getFrameCount() {
		return frameCount;
	}

	/**
	 * 取第一幀圖片
	 * 
	 * @return
	 */
	public Bitmap getImage() {
		return getFrameImage(0);
	}

	public int getLoopCount() {
		return loopCount;
	}

	private void setPixels() {
		int[] dest = new int[width * height];
		// fill in starting image contents based on last image's dispose code
		if (lastDispose > 0) {
			if (lastDispose == 3) {
				// use image before last
				int n = frameCount - 2;
				if (n > 0) {
					lastImage = getFrameImage(n - 1);
				} else {
					lastImage = null;
				}
			}
			if (lastImage != null) {
				lastImage.getPixels(dest, 0, width, 0, 0, width, height);
				// copy pixels
				if (lastDispose == 2) {
					// fill last image rect area with background color
					int c = 0;
					if (!transparency) {
						c = lastBgColor;
					}
					for (int i = 0; i < lrh; i++) {
						int n1 = (lry + i) * width + lrx;
						int n2 = n1 + lrw;
						for (int k = n1; k < n2; k++) {
							dest[k] = c;
						}
					}
				}
			}
		}

		// copy each source line to the appropriate place in the destination
		int pass = 1;
		int inc = 8;
		int iline = 0;
		for (int i = 0; i < ih; i++) {
			int line = i;
			if (interlace) {
				if (iline >= ih) {
					pass++;
					switch (pass) {
					case 2:
						iline = 4;
						break;
					case 3:
						iline = 2;
						inc = 4;
						break;
					case 4:
						iline = 1;
						inc = 2;
					}
				}
				line = iline;
				iline += inc;
			}
			line += iy;
			if (line < height) {
				int k = line * width;
				int dx = k + ix; // start of line in dest
				int dlim = dx + iw; // end of dest line
				if ((k + width) < dlim) {
					dlim = k + width; // past dest edge
				}
				int sx = i * iw; // start of line in source
				while (dx < dlim) {
					// map color and insert in destination
					int index = ((int) pixels[sx++]) & 0xff;
					int c = act[index];
					if (c != 0) {
						dest[dx] = c;
					}
					dx++;
				}
			}
		}
		image = Bitmap.createBitmap(dest, width, height, Config.ARGB_4444);
	}

	/**
	 * 取第幾幀的圖片
	 * 
	 * @param n
	 *            幀數
	 * @return 可畫的圖片，如果沒有此幀或者出錯，返回null
	 */
	public Bitmap getFrameImage(int n) {
		GifFrame frame = getFrame(n);
		if (frame == null)
			return null;
		else
			return frame.image;
	}

	/**
	 * 取當前幀圖片
	 * 
	 * @return 當前幀可畫的圖片
	 */
	public GifFrame getCurrentFrame() {
		return currentFrame;
	}

	/**
	 * 取第幾幀，每幀包含了可畫的圖片和延時時間
	 * 
	 * @param n
	 *            幀數
	 * @return
	 */
	public GifFrame getFrame(int n) {
		GifFrame frame = gifFrame;
		int i = 0;
		while (frame != null) {
			if (i == n) {
				return frame;
			} else {
				frame = frame.nextFrame;
			}
			i++;
		}
		return null;
	}

	/**
	 * 重置，進行本操作後，會直接到第一幀
	 */
	public void reset() {
		currentFrame = gifFrame;
	}

	/**
	 * 下一幀，進行本操作後，通過getCurrentFrame得到的是下一幀
	 * 
	 * @return 返回下一幀
	 */
	public GifFrame next() {
		if (isShow == false) {
			isShow = true;
			return gifFrame;
		} else {
			if (status == STATUS_PARSING) {
				if (currentFrame.nextFrame != null)
					currentFrame = currentFrame.nextFrame;
				// currentFrame = gifFrame;
			} else {
				currentFrame = currentFrame.nextFrame;
				if (currentFrame == null) {
					currentFrame = gifFrame;
				}
			}
			return currentFrame;
		}
	}

	private int readByte() {
		in = new ByteArrayInputStream(gifData);
		gifData = null;
		return readStream();
	}

	// public int read(byte[] data){
	// InputStream is = new ByteArrayInputStream(data);
	// return read(is);
	// }

	private int readStream() {
		init();
		if (in != null) {
			readHeader();
			if (!err()) {
				readContents();
				if (frameCount < 0) {
					status = STATUS_FORMAT_ERROR;
					action.parseOk(false, -1);
				} else {
					status = STATUS_FINISH;
					action.parseOk(true, -1);
				}
			}
			try {
				in.close();
			} catch (Exception e) {
				e.printStackTrace();
			}

		} else {
			status = STATUS_OPEN_ERROR;
			action.parseOk(false, -1);
		}
		return status;
	}

	private void decodeImageData() {
		int NullCode = -1;
		int npix = iw * ih;
		int available, clear, code_mask, code_size, end_of_information, in_code, old_code, bits, code, count, i, datum, data_size, first, top, bi, pi;

		if ((pixels == null) || (pixels.length < npix)) {
			pixels = new byte[npix]; // allocate new pixel array
		}
		if (prefix == null) {
			prefix = new short[MaxStackSize];
		}
		if (suffix == null) {
			suffix = new byte[MaxStackSize];
		}
		if (pixelStack == null) {
			pixelStack = new byte[MaxStackSize + 1];
		}
		// Initialize GIF data stream decoder.
		data_size = read();
		clear = 1 << data_size;
		end_of_information = clear + 1;
		available = clear + 2;
		old_code = NullCode;
		code_size = data_size + 1;
		code_mask = (1 << code_size) - 1;
		for (code = 0; code < clear; code++) {
			prefix[code] = 0;
			suffix[code] = (byte) code;
		}

		// Decode GIF pixel stream.
		datum = bits = count = first = top = pi = bi = 0;
		for (i = 0; i < npix;) {
			if (top == 0) {
				if (bits < code_size) {
					// Load bytes until there are enough bits for a code.
					if (count == 0) {
						// Read a new data block.
						count = readBlock();
						if (count <= 0) {
							break;
						}
						bi = 0;
					}
					datum += (((int) block[bi]) & 0xff) << bits;
					bits += 8;
					bi++;
					count--;
					continue;
				}
				// Get the next code.
				code = datum & code_mask;
				datum >>= code_size;
				bits -= code_size;

				// Interpret the code
				if ((code > available) || (code == end_of_information)) {
					break;
				}
				if (code == clear) {
					// Reset decoder.
					code_size = data_size + 1;
					code_mask = (1 << code_size) - 1;
					available = clear + 2;
					old_code = NullCode;
					continue;
				}
				if (old_code == NullCode) {
					pixelStack[top++] = suffix[code];
					old_code = code;
					first = code;
					continue;
				}
				in_code = code;
				if (code == available) {
					pixelStack[top++] = (byte) first;
					code = old_code;
				}
				while (code > clear) {
					pixelStack[top++] = suffix[code];
					code = prefix[code];
				}
				first = ((int) suffix[code]) & 0xff;
				// Add a new string to the string table,
				if (available >= MaxStackSize) {
					break;
				}
				pixelStack[top++] = (byte) first;
				prefix[available] = (short) old_code;
				suffix[available] = (byte) first;
				available++;
				if (((available & code_mask) == 0)
						&& (available < MaxStackSize)) {
					code_size++;
					code_mask += available;
				}
				old_code = in_code;
			}

			// Pop a pixel off the pixel stack.
			top--;
			pixels[pi++] = pixelStack[top];
			i++;
		}
		for (i = pi; i < npix; i++) {
			pixels[i] = 0; // clear missing pixels
		}
	}

	private boolean err() {
		return status != STATUS_PARSING;
	}

	private void init() {
		status = STATUS_PARSING;
		frameCount = 0;
		gifFrame = null;
		gct = null;
		lct = null;
	}

	private int read() {
		int curByte = 0;
		try {

			curByte = in.read();
		} catch (Exception e) {
			status = STATUS_FORMAT_ERROR;
		}
		return curByte;
	}

	private int readBlock() {
		blockSize = read();
		int n = 0;
		if (blockSize > 0) {
			try {
				int count = 0;
				while (n < blockSize) {
					count = in.read(block, n, blockSize - n);
					if (count == -1) {
						break;
					}
					n += count;
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
			if (n < blockSize) {
				status = STATUS_FORMAT_ERROR;
			}
		}
		return n;
	}

	private int[] readColorTable(int ncolors) {
		int nbytes = 3 * ncolors;
		int[] tab = null;
		byte[] c = new byte[nbytes];
		int n = 0;
		try {
			n = in.read(c);
		} catch (Exception e) {
			e.printStackTrace();
		}
		if (n < nbytes) {
			status = STATUS_FORMAT_ERROR;
		} else {
			tab = new int[256]; // max size to avoid bounds checks
			int i = 0;
			int j = 0;
			while (i < ncolors) {
				int r = ((int) c[j++]) & 0xff;
				int g = ((int) c[j++]) & 0xff;
				int b = ((int) c[j++]) & 0xff;
				tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b;
			}
		}
		return tab;
	}

	private void readContents() {
		// read GIF file content blocks
		boolean done = false;
		while (!(done || err())) {
			int code = read();
			switch (code) {
			case 0x2C: // image separator
				readImage();
				break;
			case 0x21: // extension
				code = read();
				switch (code) {
				case 0xf9: // graphics control extension
					readGraphicControlExt();
					break;
				case 0xff: // application extension
					readBlock();
					String app = ;
					for (int i = 0; i < 11; i++) {
						app += (char) block[i];
					}
					if (app.equals(NETSCAPE2.0)) {
						readNetscapeExt();
					} else {
						skip(); // don't care
					}
					break;
				default: // uninteresting extension
					skip();
				}
				break;
			case 0x3b: // terminator
				done = true;
				break;
			case 0x00: // bad byte, but keep going and see what happens
				break;
			default:
				status = STATUS_FORMAT_ERROR;
			}
		}
	}

	private void readGraphicControlExt() {
		read(); // block size
		int packed = read(); // packed fields
		dispose = (packed & 0x1c) >> 2; // disposal method
		if (dispose == 0) {
			dispose = 1; // elect to keep old image if discretionary
		}
		transparency = (packed & 1) != 0;
		delay = readShort() * 10; // delay in milliseconds
		transIndex = read(); // transparent color index
		read(); // block terminator
	}

	private void readHeader() {
		String id = ;
		for (int i = 0; i < 6; i++) {
			id += (char) read();
		}
		if (!id.startsWith(GIF)) {
			status = STATUS_FORMAT_ERROR;
			return;
		}
		readLSD();
		if (gctFlag && !err()) {
			gct = readColorTable(gctSize);
			bgColor = gct[bgIndex];
		}
	}

	private void readImage() {
		ix = readShort(); // (sub)image position & size
		iy = readShort();
		iw = readShort();
		ih = readShort();
		int packed = read();
		lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
		interlace = (packed & 0x40) != 0; // 2 - interlace flag
		// 3 - sort flag
		// 4-5 - reserved
		lctSize = 2 << (packed & 7); // 6-8 - local color table size
		if (lctFlag) {
			lct = readColorTable(lctSize); // read table
			act = lct; // make local table active
		} else {
			act = gct; // make global table active
			if (bgIndex == transIndex) {
				bgColor = 0;
			}
		}
		int save = 0;
		if (transparency) {
			save = act[transIndex];
			act[transIndex] = 0; // set transparent color if specified
		}
		if (act == null) {
			status = STATUS_FORMAT_ERROR; // no color table defined
		}
		if (err()) {
			return;
		}
		decodeImageData(); // decode pixel data
		skip();
		if (err()) {
			return;
		}
		frameCount++;
		// create new image to receive frame data
		image = Bitmap.createBitmap(width, height, Config.ARGB_4444);
		// createImage(width, height);
		setPixels(); // transfer pixel data to image
		if (gifFrame == null) {
			gifFrame = new GifFrame(image, delay);
			currentFrame = gifFrame;
		} else {
			GifFrame f = gifFrame;
			while (f.nextFrame != null) {
				f = f.nextFrame;
			}
			f.nextFrame = new GifFrame(image, delay);
		}
		// frames.addElement(new GifFrame(image, delay)); // add image to frame
		// list
		if (transparency) {
			act[transIndex] = save;
		}
		resetFrame();
		action.parseOk(true, frameCount);
	}

	private void readLSD() {
		// logical screen size
		width = readShort();
		height = readShort();
		// packed fields
		int packed = read();
		gctFlag = (packed & 0x80) != 0; // 1 : global color table flag
		// 2-4 : color resolution
		// 5 : gct sort flag
		gctSize = 2 << (packed & 7); // 6-8 : gct size
		bgIndex = read(); // background color index
		pixelAspect = read(); // pixel aspect ratio
	}

	private void readNetscapeExt() {
		do {
			readBlock();
			if (block[0] == 1) {
				// loop count sub-block
				int b1 = ((int) block[1]) & 0xff;
				int b2 = ((int) block[2]) & 0xff;
				loopCount = (b2 << 8) | b1;
			}
		} while ((blockSize > 0) && !err());
	}

	private int readShort() {
		// read 16-bit value, LSB first
		return read() | (read() << 8);
	}

	private void resetFrame() {
		lastDispose = dispose;
		lrx = ix;
		lry = iy;
		lrw = iw;
		lrh = ih;
		lastImage = image;
		lastBgColor = bgColor;
		dispose = 0;
		transparency = false;
		delay = 0;
		lct = null;
	}

	/**
	 * Skips variable length blocks up to and including next zero length block.
	 */
	private void skip() {
		do {
			readBlock();
		} while ((blockSize > 0) && !err());
	}
}

GifAction：

package com.ant.liao;

public interface GifAction {

	/**
	 * gif解碼觀察者
	 * @param parseStatus 解碼是否成功，成功會為true
	 * @param frameIndex 當前解碼的第幾幀，當全部解碼成功後，這裡為-1
	 */
	public void parseOk(boolean parseStatus,int frameIndex);
}

源碼已全部給出。

下面給個測試demo，看看怎麼使用：

MainActivity：

package com.home.testgifview;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;

import com.ant.liao.GifView;
import com.ant.liao.GifView.GifImageType;

public class MainActivity extends Activity implements OnClickListener {
	private GifView gifView1;
	private GifView gifView2;
	private boolean isPlaying = true;// 是否正在播放

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		gifView1 = (GifView) findViewById(R.id.main_gif1);
		// 設置要播放的GIF圖片
		gifView1.setGifImage(R.drawable.animation);
		// 設置點擊監聽器
		gifView1.setOnClickListener(this);

		gifView2 = (GifView) findViewById(R.id.main_gif2);
		// 設置解析過程中顯示方式為只顯示第一幀
		gifView2.setGifImageType(GifImageType.COVER);
		// 設置圖片大小
		gifView2.setShowDimension(300, 300);
		// 設置要播放的GIF圖片
		gifView2.setGifImage(R.drawable.loading);
	}

	@Override
	public void onClick(View v) {
		// 對於gifView1，如果正在播放，點擊則顯示第一幀，如果當前為顯示第一幀，點擊則繼續播放
		if (isPlaying) {
			// 只顯示第一幀
			gifView1.showCover();
			isPlaying = false;
		} else {
			// 繼續播放動畫（該方法在調用showCover後使用才有效）
			gifView1.showAnimation();
			isPlaying = true;
		}
	}

}

布局main.xml：