为你的tableView的自定义cell加上圆角

有的时候自己自定义了一个cell，这个cell是撑满全屏的，但是有些时候我们想要这个cell距左边10 据右边10的宽度处显示圆角，而不是整个cell

那你就需要tableView的代理方法：

#pragma mark - 
#pragma mark 设置圆角
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([cell respondsToSelector:@selector(tintColor)]) {
        if (tableView == self.tableView) {
            CGFloat cornerRadius = 5.0f;
            cell.backgroundColor = UIColor.clearColor;
            CAShapeLayer *layer = [[CAShapeLayer alloc] init];
            CGMutablePathRef pathRef = CGPathCreateMutable();
            CGRect bounds = CGRectInset(cell.bounds, 5, 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);
            layer.fillColor = [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 = 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;
        }
    }
}