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免费资源网。
