UILable自适应frame

UILabel *textlab = [[UILabel alloc]initWithFrame:CGRectMake(20, 10,ScrollView.frame.size.width - 40,260)];

textlab.text = @"测试用的随便写写ffffffffeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";

textlab.backgroundColor = [UIColor clearColor];

textlab.textColor = [UIColor blackColor];

/* 设置字号大小*/

textlab.font = [UIFont systemFontOfSize:16.0];

textlab.textAlignment = NSTextAlignmentLeft;

/* 字符串太长自动换行 */

textlab.numberOfLines = 0;

textlab.lineBreakMode =NSLineBreakByWordWrapping;

//添加此项可以设置自适应

CGSize size = CGSizeMake(280,2000);//宽度高度上限

CGSize labelsize = [textlab.text sizeWithFont:textlab.font constrainedToSize:size lineBreakMode:NSLineBreakByWordWrapping];

[textlab setFrame:CGRectMake(20, 20, labelsize.width, labelsize.height)];

[ScrollView addSubview:textlab];