主要思想是用mMatrix设置旋转中心和旋转角度，然后在onDraw(Canvas canvas) 中用canvas.drawBitmap(mForeBitmap, mMatrix, null) 画出图片；并且更新角度，调用postInvalidate()，反复循环触发onDraw(Canvas canvas) ，从而使图片动起来。

使用示例：

1. 在main_layout.xml 加入如下控件

2. 在java 代码中调用

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main_layout);

RotationLoadingView mItemLoadingImage = (RotationLoadingView) findViewById(R.id.item_loading_image);

mItemLoadingImage.startRotationAnimation();

}3. RotationLoadingView.java

package com.test.mytest;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Bitmap;

import android.graphics.Canvas;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.graphics.PaintFlagsDrawFilter;

import android.graphics.drawable.BitmapDrawable;

import android.util.AttributeSet;

import android.view.View;

/**

* 转菊花控件-->loading

*/

public class RotationLoadingView extends View {

private Context mContext;

private boolean mIsAnimation;

private int rotate;

private final int ROTATE_STEP = 10;

private int mWidth;

private int mHeight;

/** 菊花 **/

private Bitmap mForeBitmap;

/** 旋转矩阵 **/

private Matrix mMatrix = new Matrix();

/** 是否逆时针转动，默认是 **/

private boolean mClockwise = true;

private PaintFlagsDrawFilter mPaintFlagsDrawFilter;

/**

* 构造函数，初始化前景图片和背景图片

*/

public RotationLoadingView(Context context) {

super(context);

mContext = context;

init();

}

public RotationLoadingView(Context context, AttributeSet attrs) {

super(context, attrs);

mContext = context;

init();

}

/**

* 设置控件width、height

*/

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

super.onMeasure(widthMeasureSpec, heightMeasureSpec);

mWidth = mForeBitmap.getWidth();

mHeight = mForeBitmap.getHeight();

setMeasuredDimension(mWidth, mHeight);

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

// 如果位图资源已经被回收，则再重新创建一次，然后再绘图

if (mForeBitmap.isRecycled() && mIsAnimation) {

init();

}

// 如果位图资源存在，则直接绘图

if (!(mForeBitmap.isRecycled())) {

// 设置旋转中心及旋转角度

mMatrix.setRotate(rotate, mForeBitmap.getWidth() / 2, mForeBitmap.getHeight() / 2);

// 消除canvas因图片旋转所产生的锯齿

canvas.setDrawFilter(mPaintFlagsDrawFilter);

canvas.drawBitmap(mForeBitmap, mMatrix, null); // 绘制前景图

if (mIsAnimation) {

rotate = rotate + ROTATE_STEP > 360 ? 0 : rotate + ROTATE_STEP;

rotate = mClockwise ? rotate : -rotate;

postInvalidate();

}

}

}

/** 开始动画 **/

public void startRotationAnimation() {

mIsAnimation = true;

invalidate();

}

/** 停止动画 **/

public void stopRotationAnimation() {

mIsAnimation = false;

}

/**

* 覆盖父类方法 以免外部忘记调用stopRotationAnimation(), 导致内存泄漏

*/

protected void onDeAttachedToWindow() {

stopRotationAnimation();

super.onDetachedFromWindow();

}

private void init() {

mPaintFlagsDrawFilter = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);

mForeBitmap = ((BitmapDrawable) mContext.getResources().getDrawable(getResID())).getBitmap();

invalidate();

}

private int getResID() {

return R.drawable.icon_dengdai;

}

}icon_dengdai.png