Android如何在做帧动画的同时减小内存大小

Question

我正在执行帧动画和使用具有550*360分辨率的图像。我在某个地方读到，大图像应该被缩放到最小的大小和分辨率，因为1像素会将4字节的空间放入内存中。

我是一帧一帧地执行动画，但是当我从android内存分析器工具中检查它时，这会导致内存的大幅度增长，有时它会因为内存不足而崩溃。

，我知道这是由于图像的巨大大小，它被加载到内存中，但问题如下:

1. 怎样才能安全地将图像加载到内存中，而不占用太多的空间。
2. 如何在没有OOM错误的情况下进行帧动画？
3. 假设我正在使用的动画虽然占用了太多的内存空间，但是动画最终没有任何问题，所以在执行动画之后，我如何从内存中卸载图像，因为它们已经完成了动画任务，现在它们是无用的？

请告诉我的方法，并提供源代码，如果你不能回答，那么请至少告诉我如何做我已经说过的第3点。因为这是容易的。

编辑这里是我是如何做我的动画(帧一帧)

public abstract class AnimationDrawableCallback implements Drawable.Callback {


private Drawable mLastFrame;


private Drawable.Callback mWrappedCallback;

/**
 * Flag to ensure that {@link #onAnimationComplete()} is called only once, since
 * {@link #invalidateDrawable(Drawable)} may be called multiple times.
 */
private boolean mIsCallbackTriggered = false;


public AnimationDrawableCallback(AnimationDrawable animationDrawable, Drawable.Callback callback) {
    mLastFrame = animationDrawable.getFrame(animationDrawable.getNumberOfFrames() - 1);
    mWrappedCallback = callback;
}

@Override
public void invalidateDrawable(Drawable who) {
    if (mWrappedCallback != null) {
        mWrappedCallback.invalidateDrawable(who);
    }

    if (!mIsCallbackTriggered && mLastFrame != null && mLastFrame.equals(who.getCurrent())) {
        mIsCallbackTriggered = true;
        onAnimationComplete();
    }
}

@Override
public void scheduleDrawable(Drawable who, Runnable what, long when) {
    if (mWrappedCallback != null) {
        mWrappedCallback.scheduleDrawable(who, what, when);
    }
}

@Override
public void unscheduleDrawable(Drawable who, Runnable what) {
    if (mWrappedCallback != null) {
        mWrappedCallback.unscheduleDrawable(who, what);
    }
}




public abstract void onAnimationComplete();

}

对话框类，因为我在Dialog.中显示我的动画

    public class AnimationDialog extends Dialog  {


    public Activity c;
  //  public Dialog dialog;
//    public Button yes, no;
    ImageView mImageView;
    int mDrawable;
    AnimationDrawable countdownAnimation;
    Animation animationFalling;
    public AnimationDialog(Activity a, int drawable) {
        super(a);
        // TODO Auto-generated constructor stub
        this.c = a;
        this.mDrawable = drawable;
        getWindow().setWindowAnimations(R.style.DialogAnimation);
       // AnimationDialog.this.getWindow().getAttributes().windowAnimations = R.style.DialogSlideAnim;
    }

    @Override
    public void setOnCancelListener(OnCancelListener listener) {
        super.setOnCancelListener(listener);
        countdownAnimation = null;
        animationFalling = null;
        mImageView = null;
        c = null;
    }

    @Override
    public void dismiss() {
        super.dismiss();
        countdownAnimation = null;
        animationFalling = null;
        mImageView = null;
        c = null;
 //       dialog = null;



    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.custom_dialog);
        getWindow().setBackgroundDrawableResource(android.R.color.transparent);
        getWindow().setLayout(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        getWindow().setGravity(Gravity.TOP);

        //this.setCancelable(false);

        mImageView = (ImageView) findViewById(R.id.iv_animation);

        mImageView.setBackgroundResource(mDrawable);

        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                //Do something after 100ms
                ((AnimationDrawable) mImageView.getBackground()).start();
                countdownAnimation = (AnimationDrawable) mImageView.getBackground();
                countdownAnimation.setCallback(new AnimationDrawableCallback(countdownAnimation, mImageView) {
                    @Override
                    public void onAnimationComplete() {
                        // TODO Do something.
//                        Toast.makeText(c, "Animation Ended", Toast.LENGTH_SHORT).show();
                        TextView tv = (TextView) findViewById(R.id.tv);
                        Button btn = (Button) findViewById(R.id.close);
                        RelativeLayout rl = (RelativeLayout) findViewById(R.id.secondry_frame);
                        animationFalling = AnimationUtils.loadAnimation(c, R.anim.anim_falling);
                        rl.startAnimation(animationFalling);
                        tv.setVisibility(View.VISIBLE);
                        btn.setVisibility(View.VISIBLE);
                        btn.setOnClickListener(new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {

                                countdownAnimation = null;
                                animationFalling=null;
                                countdownAnimation = null;
                                AnimationDialog.this.cancel();
                                dismiss();
                               // AnimationDialog.this.dismiss();
//                                countdownAnimation = null;

                            }
                        });
                    }
                });
                countdownAnimation.start();

                // Toast.makeText(Alif.this,"Please start from the word Top",Toast.LENGTH_SHORT).show();
            }
        }, 1500);
   }
  }

和可绘图：

<?xml version="1.0" encoding="utf-8"?>

​

<item
    android:drawable="@drawable/rolling_1"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_2"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_3"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_4"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_5"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_6"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_7"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_8"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_9"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_10"
    android:duration="300" />
<item
    android:drawable="@drawable/rolling_11"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_12"
    android:duration="300" />
<item
    android:drawable="@drawable/rolling_13"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_14"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_15"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_16"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_17"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_18"
    android:duration="300" />

<item
    android:drawable="@drawable/rolling_19"
    android:duration="300" />

​

，在活动中，我称之为

 animationDialog = new AnimationDialog(Main.this, R.drawable.my_animation);
                            animationDialog.show();

Answer 1

您应该在onDestroy方法上实现一些东西。我的意思是，您应该在onDestroy中将动画的引用设置为null。这就是我现在想的，因为你没有提供适当的细节。

@Override
    protected void onDestroy() {

//set your refernce of animation class or what ever you using to null

}

Answer 2

您应该释放旧的映像来释放内存，并且只在它们即将显示时加载它们。例如，默认情况下，Android中的ViewPager只在内存中加载3页:可见的页面、前一个页面和下一个页面。当你滑动到下一页时，前一页将被删除，新的-下一页将被加载。

此外，您能提供如何加载图像和如何执行动画的来源吗？