Android 解码播放GIF图像
Android 播放GIF之前就有过一篇文章是讲述如何使用GIF文件并播放。可以通过 这里 了解关于播放GIF的一种方法。
如果前面有了解过的朋友肯定知道这上面的做法比较麻烦，又要去分解图片，又要写各种麻烦的XML文件，有点郁闷，而且还带来的直接后果是一个比较多动作的GIF图片可能会将项目的体积变大，这点很多朋友都无法接受。不过这样的好处也显而易见，就是运行的速度会比你去解码的速度要快。
以下这种方法是需要解码，但是速度的话保证不了，可能开线程的时候没有处理好吧，以下面这张图片为例做解码播放：
首先，先编写一个GIF解码的帮助类，该类提供了几个操作GIF图片的方法，比如图片的初始化呀，切换图片呀，获得整个GIF的组合数量等等，由于代码量太多，这里就不列出来，后面会提供源码供大家参考。
之后，编写一个用于可显示Gif 的组件，继承自View 并实现了Runable，代码如下：
package com.terry.gif;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
public class TypegifView extends View implements Runnable {
gifOpenHelper gHelper;
private boolean isStop = true ;
int delta;
String title;
Bitmap bmp;
// construct - refer for java
public TypegifView(Context context) {
this (context, null );
}
// construct - refer for xml
public TypegifView(Context context, AttributeSet attrs) {
super(context, attrs);
// 添加属性
TypedArray ta = context.obtainStyledAttributes(attrs,
R.styleable.gifView);
int n = ta.getIndexCount();
for ( int i = 0 ; i < n; i ++ ) {
int attr = ta.getIndex(i);
switch (attr) {
case R.styleable.gifView_src:
int id = ta.getResourceId(R.styleable.gifView_src, 0 );
setSrc(id);
break ;
case R.styleable.gifView_delay:
int idelta = ta.getInteger(R.styleable.gifView_delay, 1 );
setDelta(idelta);
break ;
case R.styleable.gifView_stop:
boolean sp = ta.getBoolean(R.styleable.gifView_stop, false );
if ( ! sp) {
setStop();
}
break ;
}
}
ta.recycle();
}
/* *
* 设置停止
*
* @param stop
*/
public void setStop() {
isStop = false ;
}
/* *
* 设置启动
*/
public void setStart() {
isStop = true ;
Thread updateTimer = new Thread( this );
updateTimer.start();
}
/* *
* 通过下票设置第几张图片显示
* @param id
*/
public void setSrc( int id) {
gHelper = new gifOpenHelper();
gHelper.read(TypegifView. this .getResources().openRawResource(id));
bmp = gHelper.getImage(); // 得到第一张图片
}
public void setDelta( int is ) {
delta = is ;
}
// to meaure its Width & Height
@Override
protected void onMeasure( int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}
private int measureWidth( int measureSpec) {
return gHelper.getWidth();
}
private int measureHeight( int measureSpec) {
return gHelper.getHeigh();
}
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
canvas.drawBitmap(bmp, 0 , 0 , new Paint());
bmp = gHelper.nextBitmap();
}
public void run() {
// TODO Auto-generated method stub
while (isStop) {
try {
this .postInvalidate();
Thread.sleep(gHelper.nextDelay() / delta);
} catch (Exception ex) {
}
}
}
}
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
public class TypegifView extends View implements Runnable {
gifOpenHelper gHelper;
private boolean isStop = true ;
int delta;
String title;
Bitmap bmp;
// construct - refer for java
public TypegifView(Context context) {
this (context, null );
}
// construct - refer for xml
public TypegifView(Context context, AttributeSet attrs) {
super(context, attrs);
// 添加属性
TypedArray ta = context.obtainStyledAttributes(attrs,
R.styleable.gifView);
int n = ta.getIndexCount();
for ( int i = 0 ; i < n; i ++ ) {
int attr = ta.getIndex(i);
switch (attr) {
case R.styleable.gifView_src:
int id = ta.getResourceId(R.styleable.gifView_src, 0 );
setSrc(id);
break ;
case R.styleable.gifView_delay:
int idelta = ta.getInteger(R.styleable.gifView_delay, 1 );
setDelta(idelta);
break ;
case R.styleable.gifView_stop:
boolean sp = ta.getBoolean(R.styleable.gifView_stop, false );
if ( ! sp) {
setStop();
}
break ;
}
}
ta.recycle();
}
/* *
* 设置停止
*
* @param stop
*/
public void setStop() {
isStop = false ;
}
/* *
* 设置启动
*/
public void setStart() {
isStop = true ;
Thread updateTimer = new Thread( this );
updateTimer.start();
}
/* *
* 通过下票设置第几张图片显示
* @param id
*/
public void setSrc( int id) {
gHelper = new gifOpenHelper();
gHelper.read(TypegifView. this .getResources().openRawResource(id));
bmp = gHelper.getImage(); // 得到第一张图片
}
public void setDelta( int is ) {
delta = is ;
}
// to meaure its Width & Height
@Override
protected void onMeasure( int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}
private int measureWidth( int measureSpec) {
return gHelper.getWidth();
}
private int measureHeight( int measureSpec) {
return gHelper.getHeigh();
}
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
canvas.drawBitmap(bmp, 0 , 0 , new Paint());
bmp = gHelper.nextBitmap();
}
public void run() {
// TODO Auto-generated method stub
while (isStop) {
try {
this .postInvalidate();
Thread.sleep(gHelper.nextDelay() / delta);
} catch (Exception ex) {
}
}
}
}
基础功能实现后。可通过view.start()开启GIF的播放，或者view.stop()停止GIF的播放，代码如下：
setContentView(R.layout.main);
Button btn = (Button) findViewById(R.id.Button01);
Button btn2 = (Button) findViewById(R.id.Button02);
final TypegifView view = (TypegifView) findViewById(R.id.gifView1);
btn.setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
view.setStop();
}
});
btn2.setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
view.setStart();
}
});
Button btn = (Button) findViewById(R.id.Button01);
Button btn2 = (Button) findViewById(R.id.Button02);
final TypegifView view = (TypegifView) findViewById(R.id.gifView1);
btn.setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
view.setStop();
}
});
btn2.setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
view.setStart();
}
});
显示效果：
源码参见：gifPlayer
本文转自 terry_龙 51CTO博客，原文链接：http://blog.51cto.com/terryblog/478018，如需转载请自行联系原作者
