NSMutableDictionary始终为null

Question

我正在开发一个简单的程序，它使用NSMutableDictionary为参数创建SOAP消息。我不明白为什么我从其他类调用的NSMutableDictionary变量总是返回null值，即使我已经添加了值。我直接尝试了setObject：forKey但它也不起作用。

这是我的代码：

SOAPLib.h    @property（nonatomic，retain）NSMutableDictionary * parameters;

Calculator.m SOAPLib * createSoap = [[SOAPLib alloc] init];

createSoap.Envelope = @"http://schemas.xmlsoap.org/soap/envelope/";
createSoap.MethodName = @"add";
createSoap.ServiceNameSpace = @"http://calculator.me.org/";

NSMutableDictionary *parameters = [[NSMutableDictionary alloc]init];
[parameters setObject:[NSNumber numberWithInt:2] forKey:@"i"];
[parameters setObject:[NSNumber numberWithInt:3] forKey:@"j"];

NSLog(@"Calc parameters: %@",parameters);  <--- returns i = 2, j = 3

[createSoap.parameters setDictionary:parameters]; <--- set

NSLog(@"create soap param: %@", createSoap.parameters); <--- returns null

Answer 1

请致电：

createSoap.parameters = parameters;

而不是

[createSoap.parameters setDictionary:parameters];