其中CPSectorView 是定义的扇形视图，它什么都没干，只是将这个扇形画出来，其.h文件如下：
@interface CPSectorView : UIView
- (instancetype)initWithRadius:(CGFloat)radius degree:(CGFloat)degree;
@end
radius 表示扇形的半径，degree表示扇形的弧度。其m文件如下：
@interface CPSectorView ()
@property (nonatomic, assign) CGFloat radius;
@property (nonatomic, assign) CGFloat degree;
@end
@implementation CPSectorView
- (instancetype)initWithRadius:(CGFloat )radius degree:(CGFloat)degree {
self = [super initWithFrame:CGRectMake(0, 0, 2 radius, 2 radius)];
if (self) {
_degree = degree;
_radius = radius;
}
self.backgroundColor = [UIColor clearColor];
return self;
}
- (void)drawRect:(CGRect)rect {
// CGContextRef context = UIGraphicsGetCurrentContext();
// UIColor *aColor = [UIColor colorWithHexString:@"ff4e7d" alpha:0.5];
// CGContextSetRGBStrokeColor(context, 1, 1, 1, 0);
// CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
// CGContextSetFillColorWithColor(context, aColor.CGColor);//填充颜色
//
// CGContextMoveToPoint(context, center.x, center.y);
// CGContextAddArc(context,center.x, center.y, _radius, _degree / 2.0, -_degree / 2.0, 1);
// CGContextClosePath(context);
// CGContextDrawPath(context, kCGPathFillStroke); //绘制路径
CGContextRef ctx = UIGraphicsGetCurrentContext();
UIGraphicsBeginImageContext(rect.size);
CGContextRef imgCtx = UIGraphicsGetCurrentContext();
CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
CGContextMoveToPoint(imgCtx, center.x,center.y);
CGContextSetFillColor(imgCtx, CGColorGetComponents([UIColor blackColor].CGColor));
CGContextAddArc(imgCtx, center.x, center.y, _radius, _degree / 2.0, -_degree / 2.0, 1);
CGContextFillPath(imgCtx);//画扇形遮罩
CGImageRef mask = CGBitmapContextCreateImage(UIGraphicsGetCurrentContext());
UIGraphicsEndImageContext();
CGContextClipToMask(ctx, self.bounds, mask);
CGFloat components[8]={
1.0, 0.306, 0.49, 0.5, //start color(r,g,b,alpha)
0.992, 0.937, 0.890, 0.5 //end color
};
//为扇形增加径向渐变色
CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
CGGradientRef gradient = CGGradientCreateWithColorComponents(space, components, NULL,2);
CGColorSpaceRelease(space),space=NULL;//release
CGPoint start = center;
CGPoint end = center;
CGFloat startRadius = 0.0f;
CGFloat endRadius = _radius;
CGContextRef graCtx = UIGraphicsGetCurrentContext();
CGContextDrawRadialGradient(graCtx, gradient, start, startRadius, end, endRadius, 0);
CGGradientRelease(gradient),gradient=NULL;//release
}
如果对扇形不做径向颜色渐变直接用注释的代码即可。具体代码就不解释了，注释和函数名字都很清晰。
以上就是对IOS 雷达效果的资料整理，后续继续补充相关资料，谢谢大家对本站的支持！
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