IOS計算文字高度

1.計算文字長度

 

   NSString* str = @"你好";

　const float kFontSize = 18.f;

    NSStringDrawingOptions options =  NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading;

    CGRect rect = [str boundingRectWithSize:CGSizeMake(MAXFLOAT,MAXFLOAT) options:options attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:kFontSize]} context:nil];

    CGFloat realHeight = ceilf(rect.size.height);

2.如果限制文字的寬度或高度，則將CGSizeMake(MAXFLOAT,MAXFLOAT)中的相應參數修改成具體的值