我想在我的应用程序中显示动画GIF图像。 我发现Android本身并不支持GIF动画。

但是它可以使用AnimationDrawable显示动画:

开发>指南>图像和图形>绘图概述

这个例子使用动画保存为框架的应用程序资源,但我需要的是直接显示动画gif。

我的计划是将动画GIF分解为帧,并将每帧添加为可绘制的AnimationDrawable。

有人知道如何从动画GIF中提取帧并将它们转换为可绘制的吗?


当前回答

在Android上显示动画GIF的方法:

电影类。正如上面提到的,它有很多bug。 WebView。使用起来很简单,而且通常很有效。但有时它开始表现不佳,而且总是在一些你没有的晦涩设备上。另外,您不能在任何类型的列表视图中使用多个实例,因为它会对内存产生影响。不过,您可以将其视为主要方法。 自定义代码解码gif为位图,并显示为Drawable或ImageView。我将提到两个库:

https://github.com/koral--/android-gif-drawable -解码器是用C语言实现的,因此非常高效。

https://code.google.com/p/giffiledecoder -解码器是在Java中实现的,所以它更容易使用。即使是大文件,仍然相当高效。

你还会发现许多基于GifDecoder类的库。这也是一个基于java的解码器,但它是通过将整个文件加载到内存中来工作的,因此它只适用于小文件。

其他回答

仅android API (android Pie)28和+使用AnimatedImageDrawable作为

// ImageView from layout
val ima : ImageView = findViewById(R.id.img_gif)
// create AnimatedDrawable 
val decodedAnimation = ImageDecoder.decodeDrawable(
        // create ImageDecoder.Source object
        ImageDecoder.createSource(resources, R.drawable.tenor))
// set the drawble as image source of ImageView
ima.setImageDrawable(decodedAnimation)
// play the animation
(decodedAnimation as? AnimatedImageDrawable)?.start()

XML代码,添加一个ImageView

<ImageView
    android:id="@+id/img_gif"
    android:background="@drawable/ic_launcher_background" <!--Default background-->
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    android:layout_width="200dp"
    android:layout_height="200dp" />

AnimatedImageDrawable是Drawable的子元素,由ImageDecoder.decodeDrawable创建

ImageDecoder. decodedrawable进一步需要ImageDecoder的实例。由ImageDecoder.createSource创建的源。

ImageDecoder。createSource只能将source作为一个名称,ByteBuffer, File, resourceId, URI, ContentResolver来创建source对象,并使用它来创建AnimatedImageDrawable作为Drawable(多态调用)

static ImageDecoder.Source  createSource(AssetManager assets, String fileName)
static ImageDecoder.Source  createSource(ByteBuffer buffer)
static ImageDecoder.Source  createSource(File file)
static ImageDecoder.Source  createSource(Resources res, int resId)
static ImageDecoder.Source  createSource(ContentResolver cr, Uri uri)

注意:你也可以使用ImageDecoder#decodeBitmap创建位图。

输出:

AnimatedDrawable还支持调整大小,帧和颜色操作

public class Test extends GraphicsActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new SampleView(this));
  }

  private static class SampleView extends View {
    private Bitmap mBitmap;
    private Bitmap mBitmap2;
    private Bitmap mBitmap3;
    private Bitmap mBitmap4;
    private Drawable mDrawable;

    private Movie mMovie;
    private long mMovieStart;

    // Set to false to use decodeByteArray
    private static final boolean DECODE_STREAM = true;

    private static byte[] streamToBytes(InputStream is) {
      ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
      byte[] buffer = new byte[1024];
      int len;
      try {
        while ((len = is.read(buffer)) >= 0) {
          os.write(buffer, 0, len);
        }
      } catch (java.io.IOException e) {
      }
      return os.toByteArray();
    }

    public SampleView(Context context) {
      super(context);
      setFocusable(true);

      java.io.InputStream is;
      is = context.getResources().openRawResource(R.drawable.icon);

      BitmapFactory.Options opts = new BitmapFactory.Options();
      Bitmap bm;

      opts.inJustDecodeBounds = true;
      bm = BitmapFactory.decodeStream(is, null, opts);

      // now opts.outWidth and opts.outHeight are the dimension of the
      // bitmap, even though bm is null

      opts.inJustDecodeBounds = false; // this will request the bm
      opts.inSampleSize = 4; // scaled down by 4
      bm = BitmapFactory.decodeStream(is, null, opts);

      mBitmap = bm;

      // decode an image with transparency
      is = context.getResources().openRawResource(R.drawable.icon);
      mBitmap2 = BitmapFactory.decodeStream(is);

      // create a deep copy of it using getPixels() into different configs
      int w = mBitmap2.getWidth();
      int h = mBitmap2.getHeight();
      int[] pixels = new int[w * h];
      mBitmap2.getPixels(pixels, 0, w, 0, 0, w, h);
      mBitmap3 = Bitmap.createBitmap(pixels, 0, w, w, h,
          Bitmap.Config.ARGB_8888);
      mBitmap4 = Bitmap.createBitmap(pixels, 0, w, w, h,
          Bitmap.Config.ARGB_4444);

      mDrawable = context.getResources().getDrawable(R.drawable.icon);
      mDrawable.setBounds(150, 20, 300, 100);

      is = context.getResources().openRawResource(R.drawable.animated_gif);

      if (DECODE_STREAM) {
        mMovie = Movie.decodeStream(is);
      } else {
        byte[] array = streamToBytes(is);
        mMovie = Movie.decodeByteArray(array, 0, array.length);
      }
    }

    @Override
    protected void onDraw(Canvas canvas) {
      canvas.drawColor(0xFFCCCCCC);

      Paint p = new Paint();
      p.setAntiAlias(true);

      canvas.drawBitmap(mBitmap, 10, 10, null);
      canvas.drawBitmap(mBitmap2, 10, 170, null);
      canvas.drawBitmap(mBitmap3, 110, 170, null);
      canvas.drawBitmap(mBitmap4, 210, 170, null);

      mDrawable.draw(canvas);

      long now = android.os.SystemClock.uptimeMillis();
      if (mMovieStart == 0) { // first time
        mMovieStart = now;
      }
      if (mMovie != null) {
        int dur = mMovie.duration();
        if (dur == 0) {
          dur = 1000;
        }
        int relTime = (int) ((now - mMovieStart) % dur);
        mMovie.setTime(relTime);
        mMovie.draw(canvas, getWidth() - mMovie.width(), getHeight()
            - mMovie.height());
        invalidate();
      }
    }
  }
}

class GraphicsActivity extends Activity {
  // set to true to test Picture
  private static final boolean TEST_PICTURE = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  }

  @Override
  public void setContentView(View view) {
    if (TEST_PICTURE) {
      ViewGroup vg = new PictureLayout(this);
      vg.addView(view);
      view = vg;
    }

    super.setContentView(view);
  }
}

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.MATCH_PARENT,
        LayoutParams.MATCH_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());

      }
    }
  }
}

类似于@Leonti说的,但更有深度:

为了解决同样的问题,我所做的是打开GIMP,隐藏除一个层之外的所有层,将其导出为其自己的图像,然后隐藏该层并取消隐藏下一个层,等等,直到每个层都有单独的资源文件。然后我可以在AnimationDrawable XML文件中使用它们作为框架。

滑翔

Image Loader Library for Android,由谷歌推荐。

Glide和毕加索的很相似,但比毕加索的快得多。 Glide比毕加索消耗的内存要少。

格莱德有而毕加索没有的东西

能够将GIF动画加载到一个简单的ImageView可能是Glide最有趣的功能。是的,你不能这样对待毕加索。 一些重要的环节-

https://github.com/bumptech/glide http://inthecheesefactory.com/blog/get-to-know-glide-recommended-by-google/en

我解决了这个问题,在将gif动画保存到手机之前将其分割成帧,这样我就不必在Android中处理它了。

然后我把每一帧下载到手机上,从中创建Drawable,然后创建AnimationDrawable -非常类似于我的问题中的例子