在iOS 7之前，常用下面这个方法计算文本高度
sizeWithFont:constrainedToSize:lineBreakMode:（Deprecated in iOS 7.0）
但是到了iOS 7 之后，这个方法就不建议使用了。提示用下面这个方法：
boundingRectWithSize:options:attributes:context:（Available in iOS 7.0 and later.）
1 -(CGSize)GetHeightDyanamic:(UILabel*)lbl 2 { 3 NSRange range = NSMakeRange(0, [lbl.text length]); 4 CGSize constraint; 5 constraint= CGSizeMake(287 ,MAXFLOAT); 6 CGSize size; 7 NSString *ver = [[UIDevice currentDevice] systemVersion]; 8 float ver_float = [ver floatValue]; 9 if (ver_float>6.0) {//版本 10 NSDictionary *attributes = [lbl.attributedText attributesAtIndex:0 effectiveRange:&range]; 11 CGSize boundingBox = [lbl.text boundingRectWithSize:constraint options: NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil].size; 12 13 size = CGSizeMake(ceil(boundingBox.width), ceil(boundingBox.height)); 14 } 15 else{ 16 17 18 size = [lbl.text sizeWithFont:[UIFont fontWithName:@"Helvetica" size:14] constrainedToSize:constraint lineBreakMode:NSLineBreakByWordWrapping]; 19 } 20 return size; 21 }
//使用方法 UILabel *_lblSelectedCountryNames;
1 _lblSelectedCountryNames.text=[ArryData componentsJoinedByString:@" "]; 2 CGSize size=[self GetHeightDyanamic:_lblSelectedCountryNames]; 3 _lblSelectedCountryNames.frame=CGRectMake(16, 240, 287, size.height);