Android加载Gif动画实现代码

Android加载Gif动画如何实现？相信大家都很好奇，本文就为大家揭晓，内容如下

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<? 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 >

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

主界面

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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); } }

自定义view

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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(); } // --------------------------------------------------------/ }

源码下载：http://xiazai.jb51.net/201610/yuanma/AndroidGifDemo(jb51.net).rar

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