为什么 .gif 动画图像在我的 Android 应用程序中没有动画效果？

Question

我正在尝试在我的应用程序中使用 .gif 动画图像，但该图像没有动画。在 iPhone 上它可以工作......为什么 Android 会阻止动画？有什么解决办法吗？

Answer 1

看起来很多人都希望动画 GIF 仅在 Android 上运行，但他们目前不希望 - 请参阅 Issue 3422 on the Android bug tracker。

根据http://androidosbeginning.blogspot.com/2010/09/gif-animation-in-android.html，您可以通过将动画 GIF 视为电影来做到这一点

类似的问题，有一个可以帮助你的答案：Android: How do a display a large animated gif given a url?

Answer 2

你可以这样做

这里是示例代码。

GIFDemo1.java

import java.io.InputStream;

import android.content.Context;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Movie;
import android.os.Bundle;
import android.view.View;

public class GIFDemo1 extends GraphicsActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new GIFView(this));
    }
    private static class GIFView extends View{

        Movie movie,movie1;
        InputStream is=null,is1=null;
        long moviestart;
        long moviestart1;
        public GIFView(Context context) {
            super(context);
            is=context.getResources().openRawResource(R.drawable.cartoon);
            is1=context.getResources().openRawResource(R.drawable.animated_gif);
            movie=Movie.decodeStream(is);
            movie1=Movie.decodeStream(is1);
            BitmapFactory.Options opts = new BitmapFactory.Options();
            opts.inJustDecodeBounds = true;    // this will request the bm
            opts.inSampleSize = 10;   
            //movie=Movie.decodeFile("C:\\cartoon.gif");
        }

        @Override
        protected void onDraw(Canvas canvas) {
            canvas.drawColor(0xFFCCCCCC);
            super.onDraw(canvas);
            long now=android.os.SystemClock.uptimeMillis();
            System.out.println("now="+now);
             if (moviestart == 0) {   // first time
                 moviestart = now;

             }
             if(moviestart1==0)
             {
                 moviestart1=now;
             }
             System.out.println("\tmoviestart="+moviestart);
             int relTime = (int)((now - moviestart) % movie.duration()) ;
             int relTime1=(int)((now - moviestart1)% movie1.duration());
             System.out.println("time="+relTime+"\treltime="+movie.duration());
             movie.setTime(relTime);
             movie1.setTime(relTime1);
             movie.draw(canvas,10,10);
             movie1.draw(canvas,10,100);
             this.invalidate();
        }
    }
}

GraphicsActivity.java

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

public class GraphicsActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public void setContentView(View view) {
        if (false) { 
            // set to true to test Picture
            ViewGroup vg = new PictureLayout(this);
            vg.addView(view);
            view = vg;
        }

        super.setContentView(view);
    }
}

PictureLayout.java

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;

public class PictureLayout extends ViewGroup {
    private final Picture mPicture = new Picture();

    public PictureLayout(Context context) {
        super(context);
    }

    public PictureLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }    

    @Override
    public void addView(View child) {
        if (getChildCount() > 1) {
            throw new IllegalStateException("PictureLayout can host only one direct child");
        }

        super.addView(child);
    }

    @Override
    public void addView(View child, int index) {
        if (getChildCount() > 1) {
            throw new IllegalStateException("PictureLayout can host only one direct child");
        }

        super.addView(child, index);
    }

    @Override
    public void addView(View child, LayoutParams params) {
        if (getChildCount() > 1) {
            throw new IllegalStateException("PictureLayout can host only one direct child");
        }

        super.addView(child, params);
    }

    @Override
    public void addView(View child, int index, LayoutParams params) {
        if (getChildCount() > 1) {
            throw new IllegalStateException("PictureLayout can host only one direct child");
        }

        super.addView(child, index, params);
    }

    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int count = getChildCount();

        int maxHeight = 0;
        int maxWidth = 0;

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                measureChild(child, widthMeasureSpec, heightMeasureSpec);
            }
        }

        maxWidth += getPaddingLeft() + getPaddingRight();
        maxHeight += getPaddingTop() + getPaddingBottom();

        Drawable drawable = getBackground();
        if (drawable != null) {
            maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
            maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
        }

        setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
                resolveSize(maxHeight, heightMeasureSpec));
    }

    private void drawPict(Canvas canvas, int x, int y, int w, int h,
                          float sx, float sy) {
        canvas.save();
        canvas.translate(x, y);
        canvas.clipRect(0, 0, w, h);
        canvas.scale(0.5f, 0.5f);
        canvas.scale(sx, sy, w, h);
        canvas.drawPicture(mPicture);
        canvas.restore();
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
        mPicture.endRecording();

        int x = getWidth()/2;
        int y = getHeight()/2;

        if (false) {
            canvas.drawPicture(mPicture);
        } else {
            drawPict(canvas, 0, 0, x, y,  1,  1);
            drawPict(canvas, x, 0, x, y, -1,  1);
            drawPict(canvas, 0, y, x, y,  1, -1);
            drawPict(canvas, x, y, x, y, -1, -1);
        }
    }

    @Override
    public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
        location[0] = getLeft();
        location[1] = getTop();
        dirty.set(0, 0, getWidth(), getHeight());
        return getParent();
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = super.getChildCount();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childLeft = getPaddingLeft();
                final int childTop = getPaddingTop();
                child.layout(childLeft, childTop,
                        childLeft + child.getMeasuredWidth(),
                        childTop + child.getMeasuredHeight());

            }
        }
    }
}

希望这对您有所帮助。 它不适用于非常复杂的 gif。