旋转图像。动画列表还是动画旋转?(安卓)

Rotate drawable Praveen的建议不会让你控制帧数。假设您希望实现一个自定义加载程序,它由8个部分组成:

animation-list 方法,您需要创建8个旋转的帧 45*frameNumber 手动角度。或者,可以使用第1帧并为其设置旋转动画:

文件 res/anim/progress_anim.xml :

<?xml version="1.0" encoding="utf-8"?>
<rotate
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360"
    android:pivotX="50%"
    android:pivotY="50%"
    android:repeatCount="infinite" />

文件 MainActivity.java

Animation a = AnimationUtils.loadAnimation(getContext(), R.anim.progress_anim);
a.setDuration(1000);
imageView.startAnimation(a);

这将为您提供平滑的动画,而不是8步。要解决此问题,我们需要实现自定义插值器:

a.setInterpolator(new Interpolator() {
    private final int frameCount = 8;

    @Override
    public float getInterpolation(float input) {
        return (float)Math.floor(input*frameCount)/frameCount;
    }
});

文件 res/values/attrs.xml :

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ProgressView">
        <attr name="frameCount" format="integer"/>
        <attr name="duration" format="integer" />
    </declare-styleable>
</resources>

文件 ProgressView.java

public class ProgressView extends ImageView {

    public ProgressView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setAnimation(attrs);
    }

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

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

    private void setAnimation(AttributeSet attrs) {
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ProgressView);
        int frameCount = a.getInt(R.styleable.ProgressView_frameCount, 12);  
        int duration = a.getInt(R.styleable.ProgressView_duration, 1000);
        a.recycle();

        setAnimation(frameCount, duration);
    }

    public void setAnimation(final int frameCount, final int duration) {
        Animation a = AnimationUtils.loadAnimation(getContext(), R.anim.progress_anim);
        a.setDuration(duration);
        a.setInterpolator(new Interpolator() {

            @Override
            public float getInterpolation(float input) {
                return (float)Math.floor(input*frameCount)/frameCount;
            }
        });
        startAnimation(a);
    }
}

activity_main.xml :

<com.example.widget.ProgressView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_progress" 
    app:frameCount="8"
    app:duration="1000"/>

文件 res/anim/progress_anim.xml文件

必须创建一个可绘制的xml文件,如下所示:

代码:

<animated-rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:pivotX="50%" android:pivotY="50%" android:fromDegrees="0"
android:toDegrees="360" android:drawable="@drawable/imagefile_to_rotate" />

我发现沃基兰的答案是最好的一个创建一个不错的阶梯/交错动画。我采纳了他的最后建议,制作了一个自定义小部件,我遇到的唯一问题是设置可见性不起作用,因为它是动画的,因此总是可见的。。。

我调整了他的代码(ProgressView.java,我将其重命名为staggeddprogress.java),如下所示:

public class StaggeredProgress extends ImageView {

private Animation staggered;

public StaggeredProgress(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    setAnimation(attrs);
}

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

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

private void setAnimation(AttributeSet attrs) {
    TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.StaggeredProgress);
    int frameCount = a.getInt(R.styleable.StaggeredProgress_frameCount, 12);  
    int duration = a.getInt(R.styleable.StaggeredProgress_duration, 1000);
    a.recycle();

    setAnimation(frameCount, duration);
}

public void setAnimation(final int frameCount, final int duration) {
    Animation a = AnimationUtils.loadAnimation(getContext(), R.anim.progress_anim);
    a.setDuration(duration);
    a.setInterpolator(new Interpolator() {

        @Override
        public float getInterpolation(float input) {
            return (float)Math.floor(input*frameCount)/frameCount;
        }
    });
    staggered = a;
    //startAnimation(a);
}

@Override
public void setVisibility(int visibility) {
    super.setVisibility(visibility);
    if( visibility == View.VISIBLE )
        startAnimation(staggered);
    else
        clearAnimation();

}


}

这样设置视图的可见性可以根据需要启动和停止动画…再次感谢vokilam!

参见此处的示例 http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/view/index.html

进度条

1. 增量 演示可以以单位递增或递减的大小旋转进度指示器。
2. 光滑的 演示用于指示一般“忙”消息的大小连续旋转进度指示器。
3. 对话框 演示ProgressDialog,它是一个弹出式对话框,承载一个进度条。这个例子演示了确定的和不确定的进度指标。
4. 演示通过设置WindowPolicy的进度指示器功能加载进度指示器的活动屏幕。

萨克的解决方案肯定有效。另一个解决方案是 <animated-rotate> 就像在讨论中一样 android:framesCount="12" android:frameDuration="100"

但是,我还没有想出如何控制动画的速度:(。

谢谢@vokilam。类似的解决方案(自动旋转的自定义视图)使用 <animation-list>

public class FramesAnimatorView extends AppCompatImageView {
    private int framesCount;
    private int duration;
    private Bitmap frameBitmap;

    public FramesAnimatorView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs);
    }

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

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

    private void init(Context context, AttributeSet attrs) {
        final TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.FramesAnimatorView);
        framesCount = typedArray.getInt(R.styleable.FramesAnimatorView_framesCount, 12);
        duration = typedArray.getInt(R.styleable.FramesAnimatorView_duration, 1200);
        typedArray.recycle();

        // Method 1: Use <rotate> as Animation (RotateAnimation) and startAnimation() (Rotate view itself).
        //method1(framesCount, duration);

        // Method 2: Use <rotate> as Drawable (RotateDrawable) and ObjectAnimator. Usable for API 21+ (because of using RotateDrawable.setDrawable).
        //method2();

        // Method 3 (Recommended): Use <animation-list> (AnimationDrawable) dynamically.
        final int frameDuration = this.duration / framesCount;
        final AnimationDrawable animationDrawable = (AnimationDrawable) getDrawable();

        for (int i = 0; i < framesCount; i++)
            animationDrawable.addFrame(
                    new RotatedDrawable(frameBitmap, i * 360f / framesCount, getResources()),
                    frameDuration);

        animationDrawable.start();
    }

    @Override public void setImageResource(int resId) { //info();
        frameBitmap = BitmapFactory.decodeResource(getResources(), resId);
        super.setImageDrawable(new AnimationDrawable());
    }

    @Override public void setImageDrawable(@Nullable Drawable drawable) { //info();
        frameBitmap = drawableToBitmap(drawable);
        super.setImageDrawable(new AnimationDrawable());
    }

    @Override public void setImageBitmap(Bitmap bitmap) { //info();
        frameBitmap = bitmap;
        super.setImageDrawable(new AnimationDrawable());
    }

    /**
     * See <a href="https://stackoverflow.com/a/21376008/5318303">@android-developer's answer on stackoverflow.com</a>.
     */
    private static class RotatedDrawable extends BitmapDrawable {
        private final float degrees;
        private int pivotX;
        private int pivotY;

        RotatedDrawable(Bitmap bitmap, float degrees, Resources res) {
            super(res, bitmap);
            pivotX = bitmap.getWidth() / 2;
            pivotY = bitmap.getHeight() / 2;
            this.degrees = degrees;
        }

        @Override public void draw(final Canvas canvas) {
            canvas.save();
            canvas.rotate(degrees, pivotX, pivotY);
            super.draw(canvas);
            canvas.restore();
        }
    }

    /**
     * See <a href="https://stackoverflow.com/a/10600736/5318303">@André's answer on stackoverflow.com</a>.
     */
    @NonNull private static Bitmap drawableToBitmap(Drawable drawable) {
        final Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        final Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);
        return bitmap;
    }
}

见 Android-FramesAnimatorView on GitHub 对于完整的(可能更新更多的)源代码。