在iOS7上实现圆角TableView

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([cell respondsToSelector:@selector(tintColor)]) {
        if (tableView == self.tableView) {
            CGFloat cornerRadius = 5.f;
            cell.backgroundColor = UIColor.clearColor;
            CAShapeLayer *layer = [[CAShapeLayer alloc] init]; //填充显示cell填充
            CAShapeLayer *borderLayer = [[CAShapeLayer alloc] init]; //用于显示边框
            CAShapeLayer *backgroundLayer = [[CAShapeLayer alloc] init]; //显示选中
            
            CGMutablePathRef pathRef = CGPathCreateMutable();
            CGMutablePathRef borderPathRef = CGPathCreateMutable(); //用于画边框
            
            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);
                CGPathAddRoundedRect(borderPathRef, nil, bounds, cornerRadius, cornerRadius);
            } else if (indexPath.row == 0) {
                //最顶端的Cell
                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));
                
                CGPathMoveToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds));
                CGPathAddArcToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds), CGRectGetMidX(bounds), CGRectGetMinY(bounds), cornerRadius);
                CGPathAddArcToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds), CGRectGetMaxX(bounds), CGRectGetMidY(bounds), cornerRadius);
                CGPathAddLineToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds));
                
                addLine = YES;
            } else if (indexPath.row == [tableView numberOfRowsInSection:indexPath.section]-1) {
                //最底端的Cell
                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));
                
                CGPathMoveToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds));
                CGPathAddArcToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds), CGRectGetMidX(bounds), CGRectGetMaxY(bounds), cornerRadius);
                CGPathAddArcToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds), CGRectGetMaxX(bounds), CGRectGetMidY(bounds), cornerRadius);
                CGPathAddLineToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds));
            } else {
                //中间的Cell
                CGPathAddRect(pathRef, nil, bounds);
                
                CGPathMoveToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMinY(bounds));
                CGPathAddLineToPoint(borderPathRef, nil, CGRectGetMinX(bounds), CGRectGetMaxY(bounds));
                
                CGPathMoveToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMinY(bounds));
                CGPathAddLineToPoint(borderPathRef, nil, CGRectGetMaxX(bounds), CGRectGetMaxY(bounds));
                
                addLine = YES;
            }
            layer.path = pathRef;
            backgroundLayer.path = pathRef;
            CFRelease(pathRef);
            layer.fillColor = [UIColor colorWithWhite:1.f alpha:0.8f].CGColor; //填充颜色
            
            borderLayer.path = borderPathRef;
            CFRelease(borderPathRef);
            borderLayer.fillColor = [UIColor clearColor].CGColor;   //f
            borderLayer.lineWidth = 1/[[UIScreen mainScreen] scale];
            borderLayer.strokeColor = tableView.separatorColor.CGColor;       //绘制边缘
            
            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-20, lineHeight);
                lineLayer.backgroundColor = tableView.separatorColor.CGColor; //绘制中间间隔线
                [layer addSublayer:lineLayer];
            }
            UIView *testView = [[UIView alloc] initWithFrame:bounds];
            [testView.layer insertSublayer:layer atIndex:0];
            [testView.layer insertSublayer:borderLayer above:layer];
            testView.backgroundColor = UIColor.clearColor;
            cell.backgroundView = testView;
            
            //以上方法存在缺陷当点击cell时还是出现cell方形效果，因此还需要添加以下方法
            UIView *selectedBackgroundView = [[UIView alloc] initWithFrame:bounds];
            backgroundLayer.fillColor = tableView.separatorColor.CGColor;
            [selectedBackgroundView.layer insertSublayer:backgroundLayer atIndex:0];
            selectedBackgroundView.backgroundColor = UIColor.clearColor;
            cell.selectedBackgroundView = selectedBackgroundView;
        }
    }
}