计算UILable的宽度

UILabel+Size.m

        myLable=[[UILabel alloc] initWithFrame:CGRectMake(0, 23, 175, 33)]; 
        [myLable setFont:[UIFont fontWithName:@"Helvetica" size:10.0]]; 
        [myLable setNumberOfLines:0]; 
        [myLable setBackgroundColor:[UIColor clearColor]]; 
        [myAdView addSubview:myLable];
        
        UIFont *font = [UIFont fontWithName:@"Helvetica" size:10.0]; 
        CGSize size = [text sizeWithFont:font constrainedToSize:CGSizeMake(175.0f, 2000.0f) lineBreakMode:UILineBreakModeWordWrap]; 
        CGRect rect=myLable.frame; 
        rect.size=size; 
        [myLable setFrame:rect]; 
        [myLable setText:text];