Android 사용자 정의 View 간단 한 원형 Progress 효과 구현

package com.yztc.customprogressview;
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.util.AttributeSet;
import android.view.View;
/**
*     
*/
public class ProgressView extends View {
private int sweepStep = 10;//       (    )
private int padding = 40;//             
private int circleColor = Color.GRAY;//     
private int sweepColor = Color.BLUE;//    
private int startAngle = 90;//    
//           
private int storke = 20;
private int sweepAngle = 0;//     
private static final int DEFAULT_WIDTH = 200;
private static final int DEFAULT_HEIGHT = 200;
public ProgressView(Context context) {
super(context);
}
//    xml           ，              
//               ，         AttributeSet  
public ProgressView(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.ProgressView);
if (array != null) {
//     xml           
sweepStep = array.getInteger(R.styleable.ProgressView_sweepStep, sweepStep);
padding = array.getInteger(R.styleable.ProgressView_padding, padding);
circleColor = array.getColor(R.styleable.ProgressView_circleColor, circleColor);
sweepColor = array.getColor(R.styleable.ProgressView_sweepColor, sweepColor);
startAngle = array.getInteger(R.styleable.ProgressView_startAngle, startAngle);
//  TypeArray  
array.recycle();
}
}
/**
*        －－    
*
* @param canvas
*/
@Override
protected void onDraw(Canvas canvas) {
Paint mPaint = new Paint();
mPaint.setAntiAlias(true); //     
//       
mPaint.setColor(circleColor);
mPaint.setStrokeWidth(storke);
mPaint.setStyle(Paint.Style.STROKE);//         
//         Height Width，  Heigh Width        ，      
canvas.drawCircle(getWidth() / 2, getWidth() / 2, getWidth() / 2 - storke / 2, mPaint);
// Log.d("tag", "onDraw: "+getWidth());
invalidate();//      view
//       
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setColor(sweepColor);
/*
drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter,Paint paint)
RectF oval                        
float startAngle          
float sweepAngle                  
boolean useCenter      true              ，               （  ），
     false，        
Paint paint         
public RectF(float left, float top, float right, float bottom)
float left       (   ) x  
float top      (   ) y   
float right,       (   ) x  
float bottom       (   ) y  
*/
//RectF      ，                
RectF rectF = new RectF(padding + storke, padding + storke, getWidth() - padding - storke, getWidth() - padding - storke);
canvas.drawArc(rectF, startAngle, sweepAngle, true, mPaint);
sweepAngle += sweepStep;//           
sweepAngle = sweepAngle > 360 ? 0 : sweepAngle;
invalidate();//  view
}
//        View     View，  onMeasure()     
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int wMode = MeasureSpec.getMode(widthMeasureSpec);
int hMode = MeasureSpec.getMode(heightMeasureSpec);
int wSize = MeasureSpec.getSize(widthMeasureSpec);
int hSize = MeasureSpec.getSize(heightMeasureSpec);
//       ，                   。
switch (wMode) {
case MeasureSpec.AT_MOST://android:layout_width="warp_content"
//      
float density = getResources().getDisplayMetrics().density;
wSize = (int) (DEFAULT_WIDTH * density);
hSize = (int) (DEFAULT_HEIGHT * density);
break;
//  xml         match_parent          ，      
case MeasureSpec.EXACTLY://android:layout_width="match_parent" android:layout_width="40dp"
wSize = hSize = Math.min(wSize, hSize);
break;
}
//    onMeasure()  ，         ，     
setMeasuredDimension(wSize, hSize);
}
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.yztc.customprogressview.MainActivity">
<com.yztc.customprogressview.ProgressView
android:id="@+id/pv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#0000ff"
app:padding="20"
app:circleColor="#aa0000"
app:sweepColor="#00aa00"
app:sweepStep="1"
app:startAngle="180"
/>
</RelativeLayout>