UIAlert with％@

Question

我正在学习Objective - C，我想用一个单词替换警告中的％@。这是我的代码：

NSString *myString = @"John";
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"Welcome:%@", myString message:...

有人可以修复代码吗？谢谢！

Answer 1

UIAlertView *myAlert = [[UIAlertView alloc] initWithTitle:[@"Welcome " stringByAppendingString:myString] ...];

Answer 2

通常当你的字符串有%@时，意味着某种字符串会替换它

您需要使用stringWithFormat:方法NSString *查看Apple Documentation for NSString *

对你而言，你只需要做以下

 NSString *myString = @"John";
 UIAlertView *myAlert = [[UIAlertView alloc] initWithTitle:[NSString stringWithFormat:@"Welcome: %@", myString]
                                                  message:@"Some Message"
                                                 delegate:self
                                        cancelButtonTitle:@"Cancel"
                                        otherButtonTitles:@"OK", nil];

您可以使{1}}中的%@替换为您的字符串（stringWithFormat:）