获取固定宽度字符串的高度,适用于自适应UILabel TableViewCell
+(CGFloat)getStringHight:(NSString*)l_str_input font:(UIFont*)l_font width:(CGFloat)l_width
{
if (l_str_input == nil || l_font == nil || l_width <= 0) {
return0.0f;
}
CGSize l_size = CGSizeMake(l_width, MAXFLOAT);
if ( [[[UIDevicecurrentDevice] systemVersion] floatValue]>=7.0 )
{
NSDictionary *attributesDictionary = [NSDictionarydictionaryWithObjectsAndKeys:
l_font, NSFontAttributeName,
nil];
CGSize textSize = [l_str_input boundingRectWithSize:l_size//用于计算文本绘制时占据的矩形块
options:NSStringDrawingUsesLineFragmentOrigin//文本绘制时的附加选项
attributes:attributesDictionary// 文字的属性
context:nil].size;
return textSize.height;
}else{
CGSize textSize = [l_str_input sizeWithFont:l_font
constrainedToSize:l_size
lineBreakMode:NSLineBreakByWordWrapping];
return textSize.height;
}
}