NSInvocation对象未获得分配的iphone sdk

我在做什么

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

但即使在处理了这一行之后，我的操作对象仍然是nil

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

这里的选择器实际上是我正在编写的一个函数，类似于：

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

-(void)initParsersetId:(NSInteger)_id_ type:(NSString *)_type_
{   
NSString *urlStr = [NSString stringWithFormat:@"apimediadetails?id=624&type=report"];
NSString *finalURLstr = [urlStr stringByAppendingString:URL];
NSURL *url = [[NSURL alloc] initWithString:finalURLstr];

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];

//Initialize the delegate.
DetailedViewObject *parser = [[DetailedViewObject alloc] initDetailedViewObject];

//Set delegate
[xmlParser setDelegate:parser];

//Start parsing the XML file.
BOOL success = [xmlParser parse];

if(success)
    NSLog(@"No Errors");
else
    NSLog(@"Error Error Error!!!"); 

}

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

谁能指出我哪里出了错吗

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

---

Thanx。选择器的名称是

initWithParserId:type:

，因此正确的行是

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:type:) object:paramObj];

---

您的

@选择器

与您的方法签名不匹配，这就是它返回nil的原因。此外，不能使用便利构造函数传递多个参数。您必须创建一个

NSInvocation

并使用

initWithInvocation:

添加参数

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];

---

不，它仍然没有得到分配。：（我已经浏览了您提供的链接，但是在initWithTarget:selector:object:，我不能直接在nsdictionary对象中传递参数吗？我必须为多达10个不同的NSInvocationObject和Scott Stevenson的方法执行此过程[这太棒了]，我想在我的例子中会引入冗余吗？而且在更改方法签名后它不会被分配。您不能在

NSDictionary

NSInvocation

中传递参数对象是可变的，因此您可以为10个不同的方法调用中的每一个编辑相同的对象。

        NSString *_type_ = @"report";
        NSNumber *_id_ = [NSNumber numberWithInt:report.reportId];

        NSDictionary *paramObj = [NSDictionary dictionaryWithObjectsAndKeys:
                                _id_, @"bla1", _type_, @"bla2",nil];

_operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(initParsersetId:) object:paramObj];