Android 实现自定义圆形进度条的实例代码

<?xml version="1.0" encoding="utf-8"?>
<resources>

  <attr name="circlecolor" format="color"></attr>
  <attr name="half" format="dimension"></attr>

  <declare-styleable name="myCircleImage">
    <attr name="circlecolor"></attr>
    <attr name="half"></attr>
  </declare-styleable>

</resources>

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class CirclePro extends View {

 private Paint paint;
 private int circleBack;//圆的背景色
 private int mschedual = 0;//用于控制动态变化
 float circleHalf; //圆的半径
 String percent = "";//绘制百分比的字符串

 @SuppressLint("Recycle")
 public CirclePro(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 paint = new Paint();
 TypedArray array = context.getTheme().obtainStyledAttributes(attrs, R.styleable.myCircleImage, defStyleAttr,0);
 @SuppressWarnings("unused")
 int leng = array.length();
 //获取自定义的属性，这里注意是R.styleable.myCircleImage_circlecolor而不是R.attr.circlecolor
 circleBack = array.getColor(R.styleable.myCircleImage_circlecolor,Color.GREEN);
 circleHalf = array.getDimension(R.styleable.myCircleImage_half,200.f);
 System.out.println(circleBack);

 }

 /**
 * 这个构造参数，当在布局文件中引用该view的时候，必须重写该构造函数
 * @param context
 * @param attrs
 */
 public CirclePro(Context context, AttributeSet attrs) {
 this(context, attrs, 0);//调用自己的构造函数

 }

 /**
 * 根据文本的
 * @param text
 * @param textSize
 * @return
 */
 public float getTextWidth(String text,float textSize) {

 TextPaint textPaint = new TextPaint();
 textPaint.setTextSize(textSize);
 return textPaint.measureText(text);
 }

 @Override
 protected void onDraw(Canvas canvas) {
 // TODO Auto-generated method stub
 super.onDraw(canvas);

 float height = getHeight();
 float width = getWidth();
// float circleHalf = (float) (width*0.7/2);

 paint.setColor(circleBack);
 paint.setAntiAlias(true);
 paint.setStyle(Paint.Style.FILL);
 canvas.drawCircle(width/2,height/2,circleHalf, paint);//画实心圆

 if (mschedual <= 100) {//，如果当前进度小于100，画实心矩形
  paint.setColor(Color.WHITE);
  canvas.drawRect(width/2-circleHalf,height/2-circleHalf,width/2+circleHalf,height/2+circleHalf - mschedual*circleHalf/50, paint);
 }

 //画当前进度的字符串
 paint.setColor(Color.BLACK);
 paint.setTextSize(30.f);
 percent = mschedual+" %";
 canvas.drawText(percent, width/2-getTextWidth(percent,30)/2,height/2+paint.getTextSize()*3/8, paint);//字体的高度=paint.getTextSize()*3/4

 //画空心圆
 paint.setColor(circleBack);
 paint.setStyle(Paint.Style.STROKE);
 canvas.drawCircle(width/2,height/2,circleHalf, paint);

 if (mschedual < 100) {//更改当前进度值，并重绘
  mschedual++;
  invalidate();
 }
 }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  xmlns:liu="http://schemas.android.com/apk/res/com.example.androidcirclepro"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".MainActivity" >

  <com.example.androidcirclepro.CirclePro
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    liu:half="90dp"
    liu:circlecolor="#fff0f0"
    />

</RelativeLayout>