1 - (void)setupLabel { 2 //准備工作 3 UILabel *textLabel = [[UILabel alloc] init]; 4 textLabel.font = [UIFont systemFontOfSize:16]; 5 NSString *str = @"222222222222222222222222222222222222222222"; 6 textLabel.text = str; 7 textLabel.backgroundColor = [UIColor redColor]; 8 textLabel.numberOfLines = 0;//根據最大行數需求來設置 9 textLabel.lineBreakMode = NSLineBreakByTruncatingTail; 10 CGSize maximumLabelSize = CGSizeMake(100, 9999);//labelsize的最大值 11 //關鍵語句 12 CGSize expectSize = [textLabel sizeThatFits:maximumLabelSize]; 13 //別忘了把frame給回label，如果用xib加了約束的話可以只改一個約束的值 14 textLabel.frame = CGRectMake(20, 70, expectSize.width, expectSize.height); 15 [self.view addSubview:textLabel]; 16 }