在iOS7中让表视图变成iOS6的圆角矩形与纯汉字文本的cell高度自适应

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([cell respondsToSelector:@selector(tintColor)]) {
        if (tableView == self.aTableView) {
            
            CGFloat cornerRadius = 5.f;
            cell.backgroundColor = UIColor.clearColor;
            CAShapeLayer *layer = [[CAShapeLayer alloc] init];
            CGMutablePathRef pathRef = CGPathCreateMutable();
            
            CGRect frame = cell.bounds;
            frame.origin.x = frame.origin.x+5;
            frame.size.width = frame.size.width-20;
            CGRect bounds = frame;
            
            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 colorWithWhite:1.f alpha:0.8f].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;

        }
    }
}

/**
 *  计算方式:
    step1：数一下一行能显示几个汉字
    step2:算一下一共几行
    step3:如果汉字不满一行按一行一算
    step4:用行数乘以行高
 */

    int lineCount = 20;
    CGFloat lbContentHeight = lbQ.text.length / lineCount;
    if (lbQ.text.length % lineCount) {
        lbContentHeight++;
    }
    lbContentHeight *= 20;