Android加载Gif动画实现代码

<?xml version="1.0" encoding="utf-8"?> 
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 android:orientation="vertical" > 
 
 <com.example.gifdemo.gifview 
 android:id="@+id/gif1" 
 android:layout_width="100dp" 
 android:layout_height="100dp" 
 android:layout_gravity="center_horizontal" 
 android:enabled="false" /> 
 
</linearlayout>

 <declare-styleable name="gifview"> 
 <attr name="gif" format="reference" /> 
 <attr name="paused" format="boolean" /> 
 </declare-styleable> 

package com.example.gifdemo; 
 
import android.app.activity; 
import android.os.bundle; 
 
public class mainactivity extends activity { 
 private gifview gif1; 
 
 @override 
 public void oncreate(bundle savedinstancestate) { 
 super.oncreate(savedinstancestate); 
 setcontentview(r.layout.activity_main); 
 gif1 = (gifview) findviewbyid(r.id.gif1); 
 // 设置背景gif图片资源 
 gif1.setmovieresource(r.raw.red); 
 } 
 
} 

package com.example.gifdemo; 
 
import android.annotation.suppresslint; 
import android.content.context; 
import android.content.res.typedarray; 
import android.graphics.canvas; 
import android.graphics.color; 
import android.graphics.movie; 
import android.os.build; 
import android.util.attributeset; 
import android.view.view; 
 
public class gifview extends view { 
 
 /** 
 * 默认为1秒 
 */ 
 private static final int default_movie_duration = 1000; 
 
 private int mmovieresourceid; 
 
 private movie mmovie; 
 
 private long mmoviestart; 
 
 private int mcurrentanimationtime = 0; 
 
 private float mleft; 
 
 private float mtop; 
 
 private float mscale; 
 
 private int mmeasuredmoviewidth; 
 
 private int mmeasuredmovieheight; 
 
 private boolean mvisible = true; 
 
 private volatile boolean mpaused = false; 
 
 /** 
 * 构造函数 
 */ 
 public gifview(context context) { 
 this(context, null); 
 } 
 
 public gifview(context context, attributeset attrs) { 
 this(context, attrs,0); 
 } 
 
 public gifview(context context, attributeset attrs, int defstyle) { 
 super(context, attrs, defstyle); 
 setviewattributes(context, attrs, defstyle); 
 setbackgroundcolor(color.parsecolor("#ffb6c1")); 
 } 
 
 @suppresslint("newapi") 
 private void setviewattributes(context context, attributeset attrs, 
 int defstyle) { 
 if (build.version.sdk_int >= build.version_codes.honeycomb) { 
 setlayertype(view.layer_type_software, null); 
 } 
 // 从描述文件中读出gif的值，创建出movie实例 
 final typedarray array = context.obtainstyledattributes(attrs, 
 r.styleable.gifview); 
 mmovieresourceid = array.getresourceid(r.styleable.gifview_gif, -1); 
 mpaused = array.getboolean(r.styleable.gifview_paused, false); 
 array.recycle(); 
 if (mmovieresourceid != -1) { 
 mmovie = movie.decodestream(getresources().openrawresource( 
  mmovieresourceid)); 
 } 
 } 
 
 /** 
 * 设置gif图资源 
 */ 
 public void setmovieresource(int movieresid) { 
 this.mmovieresourceid = movieresid; 
 mmovie = movie.decodestream(getresources().openrawresource( 
 mmovieresourceid)); 
 requestlayout(); 
 } 
 
 @override 
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) { 
 if (mmovie != null) { 
 //gif动画的宽度、高度 
 int moviewidth = mmovie.width(); 
 int movieheight = mmovie.height(); 
 //控件的宽度 
 int maximumwidth = measurespec.getsize(widthmeasurespec); 
 //gif图片宽/控件宽 
 float scalew = (float) moviewidth / (float) maximumwidth; 
 mscale = 1f / scalew; 
 mmeasuredmoviewidth = maximumwidth; 
 mmeasuredmovieheight = (int) (movieheight * mscale); 
 setmeasureddimension(mmeasuredmoviewidth, mmeasuredmovieheight); 
 } else { 
 setmeasureddimension(getsuggestedminimumwidth(), 
  getsuggestedminimumheight()); 
 } 
 } 
 
// @override 
// protected void onlayout(boolean changed, int l, int t, int r, int b) { 
// super.onlayout(changed, l, t, r, b); 
// mleft = (getwidth() - mmeasuredmoviewidth) / 2f; 
// mtop = (getheight() - mmeasuredmovieheight) / 2f; 
// mvisible = getvisibility() == view.visible; 
// } 
 
 @override 
 protected void ondraw(canvas canvas) { 
 if (mmovie != null) { 
 if (!mpaused) { 
 updateanimationtime(); 
 drawmovieframe(canvas); 
 invalidateview(); 
 } else { 
 drawmovieframe(canvas); 
 } 
 } 
 } 
 private void updateanimationtime() { 
 long now = android.os.systemclock.uptimemillis(); 
 // 如果第一帧，记录起始时间 
 if (mmoviestart == 0) { 
 mmoviestart = now; 
 } 
 // 取出动画的时长 
 int dur = mmovie.duration(); 
 if (dur == 0) { 
 dur = default_movie_duration; 
 } 
 // 算出需要显示第几帧 
 mcurrentanimationtime = (int) ((now - mmoviestart) % dur); 
 } 
 
 
 private void drawmovieframe(canvas canvas) { 
 // 设置要显示的帧，绘制即可 
 mmovie.settime(mcurrentanimationtime); 
 canvas.save(canvas.matrix_save_flag); 
 canvas.scale(mscale, mscale); 
 mmovie.draw(canvas, mleft / mscale, mtop / mscale); 
 canvas.restore(); 
 } 
 
 
 @suppresslint("newapi") 
 private void invalidateview() { 
 if (mvisible) { 
 if (build.version.sdk_int >= build.version_codes.jelly_bean) { 
 postinvalidateonanimation(); 
 } else { 
 invalidate(); 
 } 
 } 
 } 
 
 
 
 
 // --------------------以下方法未调用------------------------------------/ 
 public void setmovie(movie movie) { 
 this.mmovie = movie; 
 requestlayout(); 
 } 
 
 public movie getmovie() { 
 return mmovie; 
 } 
 
 public void setmovietime(int time) { 
 mcurrentanimationtime = time; 
 invalidate(); 
 } 
 
 public void setpaused(boolean paused) { 
 this.mpaused = paused; 
 if (!paused) { 
 mmoviestart = android.os.systemclock.uptimemillis() 
  - mcurrentanimationtime; 
 } 
 invalidate(); 
 } 
 
 public boolean ispaused() { 
 return this.mpaused; 
 } 
 
 @suppresslint("newapi") 
 @override 
 public void onscreenstatechanged(int screenstate) { 
 super.onscreenstatechanged(screenstate); 
 mvisible = screenstate == screen_state_on; 
 invalidateview(); 
 } 
 
 @suppresslint("newapi") 
 @override 
 protected void onvisibilitychanged(view changedview, int visibility) { 
 super.onvisibilitychanged(changedview, visibility); 
 mvisible = visibility == view.visible; 
 invalidateview(); 
 } 
 
 @override 
 protected void onwindowvisibilitychanged(int visibility) { 
 super.onwindowvisibilitychanged(visibility); 
 mvisible = visibility == view.visible; 
 invalidateview(); 
 } 
 // --------------------------------------------------------/ 
}