首先看一下运行效果图，程序的下拉刷新参考了视频，在视频页面也提供了源码下载，
http://www.imooc.com/learn/135
本篇主要说在此基础上增加了进度条的快速旋转和递增递减处理，在文章最后也会给出源码，这里主要描述一下所用的一个类
RoundProgressBar
package com.cayden.listview;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;
/**
* 带进度的进度条，线程安全的View，可直接在线程中更新进度
* @author cuiran
*
*/
public class RoundProgressBar extends View {
/**
* 画笔对象的引用
*/
private Paint paint;
/**
* 圆环的颜色
*/
private int roundColor;
/**
* 圆环进度的颜色
*/
private int roundProgressColor;
/**
* 中间进度百分比的字符串的颜色
*/
private int textColor;
/**
* 中间进度百分比的字符串的字体
*/
private float textSize;
/**
* 圆环的宽度
*/
private float roundWidth;
/**
* 最大进度
*/
private int max;
/**
* 当前进度
*/
private int progress;
/**
* 是否显示中间的进度
*/
private boolean textIsDisplayable;
/**
* 进度的风格，实心或者空心
*/
private int style;
public static final int STROKE = 0;
public static final int FILL = 1;
/**是否循环**/
public boolean isSpinning = false;
public RoundProgressBar(Context context) {
this(context, null);
}
public RoundProgressBar(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public RoundProgressBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
paint = new Paint();
TypedArray mTypedArray = context.obtainStyledAttributes(attrs,
R.styleable.RoundProgressBar);
//获取自定义属性和默认值
roundColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundColor, Color.RED);
roundProgressColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundProgressColor, Color.GREEN);
textColor = mTypedArray.getColor(R.styleable.RoundProgressBar_textColor, Color.GREEN);
textSize = mTypedArray.getDimension(R.styleable.RoundProgressBar_textSize, 15);
roundWidth = mTypedArray.getDimension(R.styleable.RoundProgressBar_roundWidth, 5);
max = mTypedArray.getInteger(R.styleable.RoundProgressBar_max, 360);
textIsDisplayable = mTypedArray.getBoolean(R.styleable.RoundProgressBar_textIsDisplayable, true);
style = mTypedArray.getInt(R.styleable.RoundProgressBar_style, 0);
mTypedArray.recycle();//必须Recycle
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
/**
* 画最外层的大圆环
*/
int centre = getWidth()/2; //获取圆心的x坐标
int radius = (int) (centre - roundWidth/2); //圆环的半径
paint.setColor(roundColor); //设置圆环的颜色
paint.setStyle(Paint.Style.STROKE); //设置空心
paint.setStrokeWidth(roundWidth); //设置圆环的宽度
paint.setAntiAlias(true); //消除锯齿
canvas.drawCircle(centre, centre, radius, paint); //画出圆环
/**
* 画进度百分比 现已去掉改成画图片
*/
// paint.setStrokeWidth(0);
// paint.setColor(textColor);
// paint.setTextSize(textSize);
// paint.setTypeface(Typeface.DEFAULT_BOLD); //设置字体
// int percent = (int)(((float)progress / (float)max) * 100); //中间的进度百分比，先转换成float在进行除法运算，不然都为0
// float textWidth = paint.measureText(percent + "%"); //测量字体宽度，我们需要根据字体的宽度设置在圆环中间
//
// if(textIsDisplayable && percent != 0 && style == STROKE){
// canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, paint); //画出进度百分比
// }
if(isSpinning){
/**
* 画图片
*/
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.loading02);
int width=bitmap.getWidth();
int height=bitmap.getHeight();
canvas.drawBitmap(bitmap, centre-width/2, centre-height/2 , paint);
bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.loading06);
width=bitmap.getWidth();
height=bitmap.getHeight();
canvas.drawBitmap(bitmap, centre-width/2, centre-height/2 , paint);
/**
* 画圆弧 ，画圆环的进度
*/
//设置进度是实心还是空心
paint.setStrokeWidth(roundWidth); //设置圆环的宽度
paint.setColor(roundProgressColor); //设置进度的颜色
RectF oval = new RectF(centre - radius, centre - radius, centre
+ radius, centre + radius); //用于定义的圆弧的形状和大小的界限
paint.setStyle(Paint.Style.STROKE);
canvas.drawArc(oval, progress-90, 320 , false, paint); //根据进度画圆弧
}else{
/**
* 画图片
*/
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.loading02);
int width=bitmap.getWidth();
int height=bitmap.getHeight();
canvas.drawBitmap(bitmap, centre-width/2, centre-height/2 , paint);
bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.loading05);
width=bitmap.getWidth();
height=bitmap.getHeight();
canvas.drawBitmap(bitmap, centre-width/2, centre-height/2 , paint);
/**
* 画圆弧 ，画圆环的进度
*/
//设置进度是实心还是空心
paint.setStrokeWidth(roundWidth); //设置圆环的宽度
paint.setColor(roundProgressColor); //设置进度的颜色
RectF oval = new RectF(centre - radius, centre - radius, centre
+ radius, centre + radius); //用于定义的圆弧的形状和大小的界限
paint.setStyle(Paint.Style.STROKE);
canvas.drawArc(oval, -90, progress , false, paint); //根据进度画圆弧
}
}
public synchronized int getMax() {
return max;
}
/**
* 设置进度的最大值
* @param max
*/
public synchronized void setMax(int max) {
if(max < 0){
throw new IllegalArgumentException("max not less than 0");
}
this.max = max;
}
/**
* 获取进度.需要同步
* @return
*/
public synchronized int getProgress() {
return progress;
}
/**
* Reset the count (in increment mode)
*/
public void resetCount() {
progress = 0;
invalidate();
}
/**
* Turn off spin mode
*/
public void stopSpinning() {
isSpinning = false;
progress = 0;
spinHandler.removeMessages(0);
}
/**
* Puts the view on spin mode
*/
public void spin() {
isSpinning = true;
spinHandler.sendEmptyMessage(0);
}
/**
* Increment the progress by 1 (of 360)
*/
public void incrementProgress() {
isSpinning = false;
if (progress > 360)
progress = 0;
spinHandler.sendEmptyMessage(0);
}
private Handler spinHandler = new Handler() {
/**
* This is the code that will increment the progress variable
* and so spin the wheel
*/
@Override
public void handleMessage(Message msg) {
invalidate();
if(isSpinning){
progress += 10;
if (progress > 360) {
progress = 0;
}
spinHandler.sendEmptyMessageDelayed(0, 0);
}
//super.handleMessage(msg);
}
};
/**
* 设置进度，此为线程安全控件，由于考虑多线的问题，需要同步
* 刷新界面调用postInvalidate()能在非UI线程刷新
* @param progress
*/
public synchronized void setProgress(int progress) {
if(progress < 0){
throw new IllegalArgumentException("progress not less than 0");
}
if(progress > max){
progress = max;
}
if(progress <= max){
this.progress = progress;
postInvalidate();
}
}
public int getCricleColor() {
return roundColor;
}
public void setCricleColor(int cricleColor) {
this.roundColor = cricleColor;
}
public int getCricleProgressColor() {
return roundProgressColor;
}
public void setCricleProgressColor(int cricleProgressColor) {
this.roundProgressColor = cricleProgressColor;
}
public int getTextColor() {
return textColor;
}
public void setTextColor(int textColor) {
this.textColor = textColor;
}
public float getTextSize() {
return textSize;
}
public void setTextSize(float textSize) {
this.textSize = textSize;
}
public float getRoundWidth() {
return roundWidth;
}
public void setRoundWidth(float roundWidth) {
this.roundWidth = roundWidth;
}
}
canvas.drawArc(oval, progress-90, 320 , false, paint); //根据进度画圆弧
canvas.drawArc(oval, -90, progress , false, paint); //根据进度画圆弧
可以看一下canvas.drawArc方法
public void drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter, Paint paint)
http://blog.sina.com.cn/s/blog_783ede0301012im3.html
最后给出项目的源码:
https://github.com/cayden/ListViewDemo
原文地址：http://blog.csdn.net/cuiran/article/details/42786401
