如何将NSString插入NSMutableString？

Question

我有一个NSMutableString，我需要在两个地方插入另一个NSString。我的NSMutableString是

NSMutableString *webServiceLinkWithResponses = [[NSMutableString alloc] initWithString:@"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=&ansValue="];

我需要在“question_num =”之后插入一个String（一个），在“ansValue =”之后插入另一个字符串（One），所以我的最后一个字符串应该像

http://lmsstaging.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=One&ansValue=One

对此有何建议？

Answer 1

以下内容将创建一个未经取消的NSMutableString：

NSMutableString *webServiceLinkWithResponses = [NSMutableString stringWithFormat:@"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@", stringOne, stringTwo];

如果您需要保留它，只需使用[[NSMutableString alloc] initWithFormat:@"..."]：

NSMutableString *webServiceLinkWithResponses = [[NSMutableString alloc] initWithFormat:@"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@", stringOne, stringTwo];

你真的需要它成为一个可变的字符串，你是否会在创建后更改它？如果不是简单地将NSMutableString更改为NSString，例如（这会返回自动释放的NSString，如果您需要保留，则使用[NSString alloc] initWithFormat:]：

NSString *webServiceLinkWithResponses = [NSString stringWithFormat:@"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@", stringOne, stringTwo];

Answer 2

试试这个：

NSMutableString *webServiceLinkWithResponses = [[NSMutableString alloc] initWithString:[NSString stringWithFormat: @"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@",yourFirstString,yourSecondString];

告诉我它是否有帮助！

Answer 3

我的方式是：

NSMutableString *webServiceLinkWithResponses = [[[NSString stringWithFormat: @"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@",yourFirstString,yourSecondString] mutableCopy] autorelease];

根据dreamlax的提示，你也可以使用：

NSMutableString *webServiceLinkWithResponses = [NSMutableString stringWithFormat:@"http://lmsstaging.2xprime.com/services/ParticipantService.cfc?method=setVideoExamResults&student_id=10082&course_id=VRT_TRA&lesson=904&examtype=r&question_num=%@&ansValue=%@", stringOne, stringTwo];