进度条加载

package com.baway.a1509a_view.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.baway.a1509a_view.R;

import java.util.Timer;
import java.util.TimerTask;

/**
 * 
 */

public class MyPb extends View {

    private float cx;
    private float cy;
    private float radius;
    private Paint paint;
    private int sweepAngle;
    private int color;

    public MyPb(Context context) {
        this(context, null);
    }

    public MyPb(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        //获取自定义的属性
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyPb);
        //获取颜色
        color = a.getColor(R.styleable.MyPb_circle_color, Color.BLACK);
        radius = a.getDimension(R.styleable.MyPb_circle_radius, 20);
        cx = a.getDimension(R.styleable.MyPb_circle_x, 100);
        cy = a.getDimension(R.styleable.MyPb_circle_y, 100);
        //需要回收
        a.recycle();

        paint = new Paint();
        paint.setAntiAlias(true);

        paint.setStyle(Paint.Style.STROKE);


        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
                           @Override
                           public void run() {
                               if (sweepAngle > 360) {
                                   return;
                               }
                               sweepAngle += 1;
                               //刷新View
                               //这个方法只能在主线程刷新UI
//                        invalidate();
                               //这个方法,也是刷新UI，并且可以在子线程刷新
                               postInvalidate();

                           }
                       }
                , 1000, 20);


    }


    @Override
    protected void onDraw(Canvas canvas) {
        paint.setColor(color);
        paint.setStrokeWidth(5);
        canvas.drawCircle(cx, cy, radius, paint);

        paint.setColor(Color.RED);
        RectF rectF = new RectF(cx - radius, cy - radius, cx + radius, cy + radius);
        canvas.drawArc(rectF, -90, sweepAngle, false, paint);

        //绘制文字
        int progress = (int) (sweepAngle / 360f * 100);

        paint.setStrokeWidth(0);
        paint.setColor(Color.BLACK);
        paint.setTextSize(15);
        canvas.drawText(progress + "%", cx - 5, cy, paint);
    }


}

　　

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyPb">
<attr name="circle_color" format="color"></attr>
<attr name="circle_radius" format="dimension"></attr>
<attr name="circle_x" format="dimension"></attr>
<attr name="circle_y" format="dimension"></attr>
</declare-styleable>
</resources>