ASIHTTPRequest 网络发送数据为空

在项目用模拟器发现服务器收到客户端的内容为空。经过调试发现需要增加以下代码：

request = [[ASIHTTPRequest requestWithURL:[NSURL URLWithString:t_URL]] retain];

    [request setDelegate:self];

[request appendPostData:[t_Register dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES]];

[request setRequestMethod:@"POST"];

[request addRequestHeader:@"Content-Type" value:@"application/json"];

[request setShouldAttemptPersistentConnection:NO];

[request setDidFinishSelector:@selector(requestDone:)];

[request setDidFailSelector:@selector(requestWentWrong:)];

[request startAsynchronous];