MyProgressBar.java

package com.letv.watchball.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

public class MyProgressBar extends View {

	private float x = 0;
	private float y = 0;
	private static final float offset = 0.75f;
	private ProgressBarCallBack progressBarCallBack;

	public MyProgressBar(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
	}

	public MyProgressBar(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

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

	@Override
	protected void onDraw(Canvas canvas) {

		// TODO Auto-generated method stub
		super.onDraw(canvas);

		// 首先定义一个paint
		Paint paint = new Paint();

		paint.setColor(Color.WHITE);

		paint.setStyle(Paint.Style.STROKE); // 设置空心

		/**
		 * 画最外层的大圆环
		 */
		int centre = getWidth() / 2; // 获取圆心的x坐标
		int radius = (int) (centre - 7); // 圆环的半

		paint.setStrokeWidth(5); // 设置圆环的宽度

		paint.setAntiAlias(true); // 消除锯齿

		RectF rf1 = new RectF(centre - radius, centre - radius,
				centre + radius, centre + radius);
		canvas.drawArc(rf1, x - 90, y, false, paint);
		super.onDraw(canvas);
	}

	@Override
	protected void onVisibilityChanged(View changedView, int visibility) {
		super.onVisibilityChanged(changedView, visibility);
		if (visibility == View.VISIBLE) {
			progressBarCallBack.start();
		} else {
			progressBarCallBack.stop();
		}

	}

	public void updatePosition() {
		if (y < 0)
			return;
		y += offset;
		if (y >= 360)
			y = 0;
		postInvalidate();
	}

	public int getPositon() {
		return (int) y;

	}

	public void resetProgressBar() {
		y = 0;
		updatePosition();
	}

	public interface ProgressBarCallBack {
		void start();

		void stop();
	}

	public void setProgressBarCallBack(ProgressBarCallBack progressBarCallBack) {
		this.progressBarCallBack = progressBarCallBack;
	}
}