CAShapeLayer UIBezierPath給label加圓角，應該是最好方案

//調用上面的方法，擷取 字型的 Size
    CGSize size = [self sizeWithText: @"此處是測試字型此處是測試字型" font:[UIFont systemFontOfSize:] maxSize:CGSizeMake(MAXFLOAT, MAXFLOAT)];
    UILabel * noDataLab = [[UILabel alloc]initWithFrame:CGRectMake(, , size.width+, size.height+)];
    noDataLab.text = @"此處是測試字型此處是測試字型此處是測試字型";
    noDataLab.textAlignment = NSTextAlignmentCenter;
    noDataLab.font = [UIFont systemFontOfSize:];
    noDataLab.textColor = [UIColor grayColor];
    noDataLab.layer.cornerRadius = ;
    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:noDataLab.bounds byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(, )];
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
    maskLayer.frame = noDataLab.bounds;
    maskLayer.path = maskPath.CGPath;
    noDataLab.layer.mask = maskLayer;
    //    繪制園
    [self.view addSubview:noDataLab];
    noDataLab.layer.borderWidth = ;
           

調用根據字型多少調整label的寬度

- (CGSize)sizeWithText:(NSString *)text font:(UIFont *)font maxSize:(CGSize)maxSize
{
    NSDictionary *attrs = @{NSFontAttributeName : font};
    return [text boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:attrs context:nil].size;
}