UILabel *textLabel = [[UILabel alloc] init];
textLabel.font = [UIFont systemFontOfSize:16];
NSString *str = @"222222222222222222222222222222222222222222";
textLabel.text = str;
textLabel.backgroundColor = [UIColor redColor];
textLabel.numberOfLines = 0;//根據(jù)最大行數(shù)需求來(lái)設(shè)置
textLabel.lineBreakMode = NSLineBreakByTruncatingTail;
CGSize maximumLabelSize = CGSizeMake(100, 9999);//labelsize的最大值
//關(guān)鍵語(yǔ)句
CGSize expectSize = [textLabel sizeThatFits:maximumLabelSize];
//別忘了把frame給回label，如果用xib加了約束的話可以只改一個(gè)約束的值
textLabel.frame = CGRectMake(20, 70, expectSize.width, expectSize.height);
[self.view addSubview:textLabel];
