尝试以下方法,我的一个应用程序也具有相同的功能,并且我使用以下方法完成了它。
-(void)addDashedBorder
{
//border definitions
CGFloat cornerRadius = 0;
CGFloat borderWidth = 1;
NSInteger dashPattern1 = 4;
NSInteger dashPattern2 = 4;
UIColor *lineColor = [UIColor blackColor];
//drawing
CGRect frame = view.bounds;
CAShapeLayer *_shapeLayer = [CAShapeLayer layer];
//creating a path
CGMutablePathRef path = CGPathCreateMutable();
//drawing a border around a view
CGPathMoveToPoint(path, NULL, 0, frame.size.height - cornerRadius);
CGPathAddLineToPoint(path, NULL, 0, cornerRadius);
CGPathAddArc(path, NULL, cornerRadius, cornerRadius, cornerRadius, M_PI, -M_PI_2, NO);
CGPathAddLineToPoint(path, NULL, frame.size.width - cornerRadius, 0);
CGPathAddArc(path, NULL, frame.size.width - cornerRadius, cornerRadius, cornerRadius, -M_PI_2, 0, NO);
CGPathAddLineToPoint(path, NULL, frame.size.width, frame.size.height - cornerRadius);
CGPathAddArc(path, NULL, frame.size.width - cornerRadius, frame.size.height - cornerRadius, cornerRadius, 0, M_PI_2, NO);
CGPathAddLineToPoint(path, NULL, cornerRadius, frame.size.height);
CGPathAddArc(path, NULL, cornerRadius, frame.size.height - cornerRadius, cornerRadius, M_PI_2, M_PI, NO);
//path is set as the _shapeLayer object's path
_shapeLayer.path = path;
CGPathRelease(path);
_shapeLayer.backgroundColor = [[UIColor clearColor] CGColor];
_shapeLayer.frame = frame;
_shapeLayer.masksToBounds = NO;
[_shapeLayer setValue:[NSNumber numberWithBool:NO] forKey:@"isCircle"];
_shapeLayer.fillColor = [[UIColor clearColor] CGColor];
_shapeLayer.strokeColor = [lineColor CGColor];
_shapeLayer.lineWidth = borderWidth;
_shapeLayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:dashPattern1], [NSNumber numberWithInt:dashPattern2], nil];
_shapeLayer.lineCap = kCALineCapRound;
//_shapeLayer is added as a sublayer of the view, the border is visible
[view.layer addSublayer:_shapeLayer];
view.layer.cornerRadius = cornerRadius;
}