自定义View-圆球进度的实现（仿360波浪进度）

一般最常用的方法就是 画线的方式，先绘sin线或贝塞尔曲线，然后从左到右绘制竖线，然后再裁剪圆区域。

今天我这用图片bitmap的方式,大概的方法原理是：

（1）首先用clipPath裁剪园区域，

（2）然后用4张图来不断绘制到画布上，再用偏移量来控制移动的速度，从而形成波浪动态效果。

（3）有一点需要注意的是，裁剪圆的时候用到的clipPath这个方法，在android 4.1，和4.2等某些系统上，裁剪出来不是圆，而是矩形，针对这些系统 需要在manifest.xml文件的activity中将硬件加速关掉，因为默认是开启的。即添加这个：android:hardwareAccelerated="false"

（1）自定义波浪View的实现：

/**
 * 
 * @author hjy
 * 用波浪效果实现横滚动画
 */
public class SinkingView extends FrameLayout {
    private static final int DEFAULT_TEXTCOLOT = 0xFFFFFFFF;

    private static final int DEFAULT_TEXTSIZE = 25;

    private float mPercent;

    private Paint mPaint = new Paint();

    private Bitmap mBitmap;

    private Bitmap mScaledBitmap;

    private float mLeft;

    private int mSpeed = 15;

    private int mRepeatCount = 0;

    private Status mFlag = Status.NONE;

    private int mTextColor = DEFAULT_TEXTCOLOT;

    private int mTextSize = DEFAULT_TEXTSIZE;

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

    public void setTextColor(int color) {
        mTextColor = color;
    }

    public void setTextSize(int size) {
        mTextSize = size;
    }

    public void setPercent(float percent) {
        mFlag = Status.RUNNING;
        mPercent = percent;
        postInvalidate();

    }

    public void setStatus(Status status) {
        mFlag = status;
    }

    public void clear() {
        mFlag = Status.NONE;
        if (mScaledBitmap != null) {
            mScaledBitmap.recycle();
            mScaledBitmap = null;
        }

        if (mBitmap != null) {
            mBitmap.recycle();
            mBitmap = null;
        }
    }
    
    @Override
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(canvas);
        int width = getWidth();
        int height = getHeight();
        
        //裁剪成圆区域
        Path path = new Path();
        canvas.save();
        path.reset();
        canvas.clipPath(path);
        path.addCircle(width / 2, height / 2, width / 2, Direction.CCW);
        canvas.clipPath(path, Op.REPLACE);//UNION REPLACE REVERSE_DIFFERENCE XOR
        
        if (mFlag == Status.RUNNING) {
            if (mScaledBitmap == null) {
                mBitmap = BitmapFactory.decodeResource(getContext().getResources(), R.drawable.wave4);
                mScaledBitmap = Bitmap.createScaledBitmap(mBitmap, mBitmap.getWidth(), getHeight(), false);
                mBitmap.recycle();
                mBitmap = null;
                mRepeatCount = (int) Math.ceil(getWidth() / mScaledBitmap.getWidth() + 0.5) + 1;
            }
            for (int idx = 0; idx < mRepeatCount; idx++) {
                canvas.drawBitmap(mScaledBitmap, mLeft + (idx - 1) * mScaledBitmap.getWidth(), (1-mPercent) * getHeight(), null);
            }
//            String str = (int) (mPercent * 100) + "%";
//            mPaint.setColor(mTextColor);
//            mPaint.setTextSize(mTextSize);
//            mPaint.setStyle(Style.FILL);
//            canvas.drawText(str, (getWidth() - mPaint.measureText(str)) / 2, getHeight() / 2 + mTextSize / 2, mPaint);

            mLeft += mSpeed;
            if (mLeft >= mScaledBitmap.getWidth())
                mLeft = 0;
            // 绘制外圆环
//            mPaint.setStyle(Paint.Style.STROKE);
//            mPaint.setStrokeWidth(1);
//            mPaint.setAntiAlias(true);
//            mPaint.setColor(Color.parseColor("#03f0ee"));
//            canvas.drawCircle(width / 2, height / 2, width / 2 - 2, mPaint);

            postInvalidateDelayed(20);
        }
        canvas.restore();

    }

    public enum Status {
        RUNNING, NONE
    }
}

（2）布局文件的实现：

（3）如何使用自定义波浪View：

    private SinkingView sv_menu_pitchs = (SinkingView) findViewById(R.id.sv_menu_pitchs);
    private float percent = 0;
	percent = 1.50f;
	sv_menu_pitchs.setPercent(percent);