IOS 字符串高度

- (void)testStrFrame
{
NSString  *ContentStr = @"ennghjkjhgfdfghjkjhgfwertyuiowertyuioertyuqwertyuiedrtyuiwertyuwertywertyyuiowertyuioertyuqwertyuiedrtyuiwertyuwertywerty";

CGSize size = [ContentStr getSizeWithFont:[UIFont systemFontOfSize:15] constrainedToSize:CGSizeMake(320, MAXFLOAT)];

UILabel *_labelTest = [[UILabel alloc]init];
_labelTest.numberOfLines = 0;
_labelTest.font = [UIFont systemFontOfSize:15];
_labelTest.frame = CGRectMake(0, 64, 320,size.height);
_labelTest.text = ContentStr;

[self.view addSubview:_labelTest];

}