Android自定义View实现圆环进度条

本文实例为大家分享了android自定义view实现圆环进度条的具体代码，供大家参考，具体内容如下

效果展示

动画效果

view实现

1.底层圆环是灰色背景
2.上层圆环是红色背景
3.使用动画画一条弧线

view

/**
 * 圆环进度条
 */
public class roundprogressbar extends view {
 //绘制矩形区域
 private rectf rectf;
 //起始角度
 private float startangle;
 //扫过角度
 private float sweepangle;
 //画笔
 private paint paint;
 //默认控件大小
 private int defoutsize;
 //默认线条宽度
 private int defoutline;
 private int strokewidth;

 private pointf pointf = new pointf();


 public roundprogressbar(context context) {
  super(context);
  initdata();
 }

 public roundprogressbar(context context, attributeset attrs) {
  super(context, attrs);
  initdata();
 }

 /**
  * 参数初始化
  */
 private void initdata() {
  startangle = 0;
  sweepangle = 0;
  defoutsize = 400;
  defoutline = 20;
  strokewidth = 20;

  rectf = new rectf();

  //抗锯齿画笔
  paint = new paint(paint.anti_alias_flag);
  paint.setcolor(color.gray);
  paint.setstrokewidth(defoutline);
  //笔帽样式
  paint.setstrokecap(paint.cap.round);
  paint.setstyle(paint.style.stroke);
 }

 /**
  * xml -----> 提供可绘制位置
  *
  * @param widthmeasurespec 宽
  * @param heightmeasurespec 高
  */
 @override
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
  super.onmeasure(widthmeasurespec, heightmeasurespec);
  setmeasureddimension(defoutsize, defoutsize);
 }

 /**
  * 当大小时改变回调
  *
  * @param w
  * @param h
  * @param oldw
  * @param oldh
  */
 @override
 protected void onsizechanged(int w, int h, int oldw, int oldh) {
  super.onsizechanged(w, h, oldw, oldh);

  pointf.x = w >> 1;
  pointf.y = h >> 1;

  rectf.top = strokewidth >> 1;
  rectf.bottom = h - (strokewidth >> 1);
  rectf.left = strokewidth >> 1;
  rectf.right = w - (strokewidth >> 1);

 }

 /**
  * 绘制
  *
  * @param canvas
  */
 @override
 protected void ondraw(canvas canvas) {
  super.ondraw(canvas);

  //画布旋转
  paint.setcolor(color.gray);
  canvas.rotate(135, pointf.x, pointf.y);
  //绘制圆环
  canvas.drawarc(rectf, startangle, 270, false, paint);

  paint.setcolor(color.red);
  canvas.drawarc(rectf, startangle, sweepangle, false, paint);

 }

 public void setprogress(float index) {
 //防止数值越界
  if (index > 1 || index < 0) {
   return;
  }
  valueanimator valueanimator = valueanimator.offloat(0, index);
  valueanimator.setduration(3000);
  valueanimator.setinterpolator(new decelerateinterpolator());
  valueanimator.addupdatelistener(new valueanimator.animatorupdatelistener() {
   @override
   public void onanimationupdate(valueanimator animation) {
    sweepangle = (float) animation.getanimatedvalue() * 270;
    //重写绘制
    invalidate();
   }
  });
  valueanimator.start();

 }
}

最后在activity中使用setprogress方法赋值进度条的进度来实现效果

progressview.setprogress(0.8f);

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。