public class MeiTuanRefreshFirstStepView extends View{

    private Bitmap initialBitmap;

    private int measuredWidth;

    private int measuredHeight;

    private Bitmap endBitmap;

    private float mCurrentProgress;

    private Bitmap scaledBitmap;

    public MeiTuanRefreshFirstStepView(Context context, AttributeSet attrs,

            int defStyle) {

        super(context, attrs, defStyle);

        init(context);

    }

    public MeiTuanRefreshFirstStepView(Context context, AttributeSet attrs) {

        super(context, attrs);

        init(context);

    }

    public MeiTuanRefreshFirstStepView(Context context) {

        super(context);

        init(context);

    }

    private void init(Context context) {

        //这个就是那个椭圆形图片

        initialBitmap = Bitmap.createBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.pull_image));

        //这个是第二个状态娃娃的图片，之所以要这张图片，是因为第二个状态和第三个状态的图片的大小是一致的，而第一阶段

        //椭圆形图片的大小与第二阶段和第三阶段不一致，因此我们需要根据这张图片来决定第一张图片的宽高，来保证

        //第一阶段和第二、三阶段的View的宽高一致

        endBitmap = Bitmap.createBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.pull_end_image_frame_05));

    }

    /**

     * 重写onMeasure方法主要是设置wrap_content时 View的大小

     * @param widthMeasureSpec

     * @param heightMeasureSpec

     */

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        //根据设置的宽度来计算高度  设置为符合第二阶段娃娃图片的宽高比例

        setMeasuredDimension(measureWidth(widthMeasureSpec),measureWidth(widthMeasureSpec)*endBitmap.getHeight()/endBitmap.getWidth());

    }

    /**

     * 当wrap_content的时候，宽度即为第二阶段娃娃图片的宽度

     * @param widMeasureSpec

     * @return

     */

    private int measureWidth(int widMeasureSpec){

        int result = 0;

        int size = MeasureSpec.getSize(widMeasureSpec);

        int mode = MeasureSpec.getMode(widMeasureSpec);

        if (mode == MeasureSpec.EXACTLY){

            result = size;

        }else{

            result = endBitmap.getWidth();

            if (mode == MeasureSpec.AT_MOST){

                result = Math.min(result,size);

            }

        }

        return result;

        }

    /**

     * 在onLayout里面获得测量后View的宽高

     * @param changed

     * @param left

     * @param top

     * @param right

     * @param bottom

     */

    @Override

    protected void onLayout(boolean changed, int left, int top, int right,

            int bottom) {

        super.onLayout(changed, left, top, right, bottom);

        measuredWidth = getMeasuredWidth();

        measuredHeight = getMeasuredHeight();

        //根据第二阶段娃娃宽高  给椭圆形图片进行等比例的缩放

        scaledBitmap = Bitmap.createScaledBitmap(initialBitmap, measuredWidth,measuredWidth*initialBitmap.getHeight()/initialBitmap.getWidth(), true);

    }

    @Override

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        //这个方法是对画布进行缩放，从而达到椭圆形图片的缩放，第一个参数为宽度缩放比例，第二个参数为高度缩放比例，

        canvas.scale(mCurrentProgress, mCurrentProgress, measuredWidth/2, measuredHeight/2);

        //将等比例缩放后的椭圆形画在画布上面

        canvas.drawBitmap(scaledBitmap,0,measuredHeight/4,null);

    }

    /**

     * 设置缩放比例，从0到1  0为最小 1为最大

     * @param currentProgress

     */

    public void setCurrentProgress(float currentProgress){

        mCurrentProgress = currentProgress;

    }

public class MainActivity extends Activity implements OnMeiTuanRefreshListener{

    private MeiTuanListView mListView;

    private List<string> mDatas;

    private ArrayAdapter<string> mAdapter;

    private final static int REFRESH_COMPLETE = 0;

    /**

     * mHandler运行在主线程，因为setOnRefreshComplete需要改变ui，必须在主线程去改变ui

     * 所以在handleMessage中调用mListView.setOnRefreshComplete();

     */

    private Handler mHandler = new Handler(){

        public void handleMessage(android.os.Message msg) {

            switch (msg.what) {

            case REFRESH_COMPLETE:

                mListView.setOnRefreshComplete();

                mAdapter.notifyDataSetChanged();

                mListView.setSelection(0);

                break;

            default:

                break;

            }

        };

    };

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mListView = (MeiTuanListView) findViewById(R.id.listview);

        String[] data = new String[]{hello world,hello world,hello world,hello world,

                hello world,hello world,hello world,hello world,hello world,

                hello world,hello world,hello world,hello world,hello world,};

        mDatas = new ArrayList<string>(Arrays.asList(data));

        mAdapter = new ArrayAdapter<string>(this, android.R.layout.simple_list_item_1,mDatas);

        mListView.setAdapter(mAdapter);

        mListView.setOnMeiTuanRefreshListener(this);

    }

    @Override

    public void onRefresh() {

        new Thread(new Runnable() {

            @Override

            public void run() {

                try {

                    Thread.sleep(3000);

                    mDatas.add(0, new data);

                    mHandler.sendEmptyMessage(REFRESH_COMPLETE);

                } catch (InterruptedException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

        }).start();

    }

}