自定义UITableViewCell 上面的控件设置圆角 自定义cell的drawRect 方法,并在该方法里面设置圆角

-(void)drawRect:(CGRect)rect {

  [super drawRect:rect];

  self.avada.layer.cornerRadius = self.avada.width * 0.5;
  self.avada.layer.borderColor = [UIColor whiteColor].CGColor;
  self.avada.layer.borderWidth = 2;
  self.avada.layer.masksToBounds =  YES;
}

🌰section分组设置圆角

 // 1:tableview 分组圆角

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{
if ([cell respondsToSelector:@selector(tintColor)]) {
    //        if (tableView == self.tableView) {
    CGFloat cornerRadius = 10.f;
    cell.backgroundColor = UIColor.clearColor;
    CAShapeLayer *layer = [[CAShapeLayer alloc] init];
    CGMutablePathRef pathRef = CGPathCreateMutable();
    CGRect bounds = CGRectInset(cell.bounds, 10, 0);
    BOOL addLine = NO;
    if (indexPath.row == 0 && indexPath.row == [tableView numberOfRowsInSection:indexPath.section]-1) {
        CGPathAddRoundedRect(pathRef, nil, bounds, cornerRadius, cornerRadius);
    } else if (indexPath.row == 0) {

        CGPathMoveToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds));
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds), CGRectGetMidX(bounds), CGRectGetMinY(bounds), cornerRadius);
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds), CGRectGetMaxX(bounds), CGRectGetMidY(bounds), cornerRadius);
        CGPathAddLineToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds));
        addLine = YES;
        
    } else if (indexPath.row == [tableView numberOfRowsInSection:indexPath.section]-1) {
        CGPathMoveToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds));
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds), CGRectGetMidX(bounds), CGRectGetMaxY(bounds), cornerRadius);
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds), CGRectGetMaxX(bounds), CGRectGetMidY(bounds), cornerRadius);
        CGPathAddLineToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds));
    } else {
        CGPathAddRect(pathRef, nil, bounds);
        addLine = YES;
    }
    layer.path = pathRef;
    CFRelease(pathRef);
    //颜色修改
    layer.fillColor = [UIColor colorWithWhite:1.f alpha:0.5f].CGColor;
    layer.strokeColor=[UIColor blackColor].CGColor;
    if (addLine == YES) {
        CALayer *lineLayer = [[CALayer alloc] init];
        CGFloat lineHeight = (1.f / [UIScreen mainScreen].scale);
        lineLayer.frame = CGRectMake(CGRectGetMinX(bounds)+10, bounds.size.height-lineHeight, bounds.size.width-10, lineHeight);
        lineLayer.backgroundColor = tableView.separatorColor.CGColor;
        [layer addSublayer:lineLayer];
    }
    UIView *testView = [[UIView alloc] initWithFrame:bounds];
    [testView.layer insertSublayer:layer atIndex:0];
    testView.backgroundColor = UIColor.clearColor;
    cell.backgroundView = testView;
}
 //    }
}

2:collection 设置分组圆角

- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath{

 if ([cell respondsToSelector:@selector(tintColor)]) {
    //        if (tableView == self.tableView) {
    CGFloat cornerRadius = 6.f;
    cell.backgroundColor = UIColor.clearColor;
    CAShapeLayer *layer = [[CAShapeLayer alloc] init];
    CGMutablePathRef pathRef = CGPathCreateMutable();
    CGRect bounds = CGRectInset(cell.bounds, 10, 0);
    BOOL addLine = NO;

    //只设置最后一行圆角(如需要设置整个section为圆角,参考tableview Section 设置)
    if (indexPath.row == [collectionView numberOfItemsInSection:indexPath.section]-1 || (indexPath.row == 0 && indexPath.row == [collectionView numberOfItemsInSection:indexPath.section]-1)) {
        
        CGPathMoveToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds));
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds), CGRectGetMidX(bounds), CGRectGetMaxY(bounds), cornerRadius);
        CGPathAddArcToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds), CGRectGetMaxX(bounds), CGRectGetMidY(bounds), cornerRadius);
        CGPathAddLineToPoint(pathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds));
    } else {//其他行为举行
        CGPathAddRect(pathRef, nil, bounds);
        addLine = YES;
    }
    
    layer.path = pathRef;
    CFRelease(pathRef);
    
    //颜色修改
    layer.fillColor = [UIColor whiteColor].CGColor;
    layer.strokeColor=[UIColor clearColor].CGColor;
    
    if (addLine == YES) {
        
        CALayer *lineLayer = [[CALayer alloc] init];
        CGFloat lineHeight = (1.f / [UIScreen mainScreen].scale);
        lineLayer.frame = CGRectMake(CGRectGetMinX(bounds)+10, bounds.size.height-lineHeight, bounds.size.width-10, lineHeight);
        lineLayer.backgroundColor = BackgroundLightGray.CGColor;
        
        [layer addSublayer:lineLayer];
    }
    UIView *testView = [[UIView alloc] initWithFrame:bounds];
    [testView.layer insertSublayer:layer atIndex:0];
    testView.backgroundColor = BackGround_COLOR;
    cell.backgroundView = testView;
  }
}

🌰UIView设置某个圆角:以设置上面两个为圆角例

//设置上面两个为圆角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect: _contentView.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(6,6)];
//创建 layer
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = _contentView.bounds;
//赋值
maskLayer.path = maskPath.CGPath;
_contentView.layer.mask = maskLayer;