IOS实战 (2) 之 环形渐变色 进度展示条

实现效果图

实现思路

自定义 View

添加 Label

使用 CAShapeLayer 绘制两个同心圆

加动画

核心代码

1.设置 圆形 路径

[UIBezierPath bezierPathWithArcCenter:<(CGPoint)> radius:<(CGFloat)> startAngle:<(CGFloat)> endAngle:<(CGFloat)> clockwise:<(BOOL)>

这个工厂方法用于画弧，参数说明如下：
center: 弧线中心点的坐标
radius: 弧线所在圆的半径
startAngle: 弧线开始的角度值
endAngle: 弧线结束的角度值
clockwise: 是否顺时针画弧线

2.创建 CAshapeLayer(绘制两个同心圆)

self.garyCircleLayer = [CAShapeLayer layer];
self.garyCircleLayer.frame = self.bounds;
self.garyCircleLayer.fillColor = [[UIColor            clearColor] CGColor];
//圆形边界颜色
self.garyCircleLayer.strokeColor = [[UIColor  colorWithHex:0xd5e0e2] CGColor] ;
self.garyCircleLayer.opacity = 0.5;
self.garyCircleLayer.lineCap = kCALineCapRound;
self.garyCircleLayer.lineWidth = _grayCircleLineWidth;
self.garyCircleLayer.path = [garypath CGPath];
[self.layer addSublayer:self.garyCircleLayer];

3.设置渐变图层

self.gradientLayer = [CAGradientLayer layer];
self.gradientLayer.frame = self.bounds;
[self.gradientLayer setColors:[NSArray arrayWithObjects: (id)[[UIColor colorWithHex:0xe2962c] CGColor], (id)[[UIColor colorWithHex:0xf5eb70 ] CGColor],nil]];
[self.gradientLayer setLocations:@[@0.2, @0.5, @0.7, @1]];
[self.gradientLayer setStartPoint:CGPointMake(0, 0)];
[self.gradientLayer setEndPoint:CGPointMake(1, 0)];
[self.gradientLayer setMask:self.progressLayer];

4.设置动画

// 复原
[CATransaction begin];
[CATransaction setDisableActions:NO];
[CATransaction setAnimationTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
[CATransaction setAnimationDuration:0];
self.progressLayer.strokeEnd = 0;
[CATransaction commit];

[CATransaction begin];
[CATransaction setDisableActions:NO];
[CATransaction setAnimationTimingFunction:[CAMediaTimingFunction   functionWithName:kCAMediaTimingFunctionLinear]];
[CATransaction   setAnimationDuration:kAnimationTime];
self.progressLayer.strokeEnd = _percent ;
[CATransaction commit];

总结

注意为了适应在 Xib 中创建 的View,需要在 layoutSubview 重新去设置 View 的 Frame.

源码下载

源码下载链接