调用方法时属性访问导致未使用错误

Posted 2023-03-16

【中文标题】调用方法时属性访问导致未使用错误

【英文标题】：Property access result unused error while invoking a method

【发布时间】：2016-03-23 10:32:14

【问题描述】：

我使用下面的代码来调用一个方法，

APIRequest *apiRequest = [[APIRequest alloc]init];
apiRequest.pendingShipmentDetails ;

我收到以下警告，

属性访问结果未使用的 getter 不应用于 side 效果

这是什么意思？

该方法同时被调用两次

以下是我的方法，

-(void)pendingShipmentDetails

    keyChain = [[KeyChainItemWrapper alloc] initWithIdentifier:@"LoginController" accessGroup:nil];
    NSString *username = [keyChain objectForKey:(__bridge id)(kSecAttrLabel)];

    NSString *bodyString = [NSString stringWithFormat:@"\"method\":\"pending_shipment_details\",\"data\":\"username\":\"%@\"",username];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"url"]];
    NSData *postData = [bodyString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
    [request setHTTPBody:postData];
    [request setHTTPMethod:@"POST"];
    NSString *postLength = [NSString stringWithFormat:@"%lu", (unsigned long)[postData length]];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];

    NSOperationQueue *queue = [[NSOperationQueue alloc] init];

    [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError)
     
         if ([data length] > 0 && connectionError == nil)
         
             [self receivedPendingShipmentDetailsData:data];
             NSString* pendingResponse = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
             NSData *jsonData = [pendingResponse dataUsingEncoding:NSUTF8StringEncoding];
             NSDictionary *jsonDic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments error:nil];
             NSDictionary *valueDict = [jsonDic objectForKey:@"value"];

             NSArray *details = [valueDict objectForKey:@"details"];

             NSMutableArray* arrayList = [[NSMutableArray alloc] init];

             for (NSDictionary *response in details) 
                 NSString *invoiceNo = [response valueForKey:@"invoice_no"];
                 NSString *shipmentNumber = [response valueForKey:@"shipment_no"];
                 NSString *invoiceDate = [response valueForKey:@"invoice_date"];
                 NSString *proformaInvoiceNumber = [response valueForKey:@"proforma_invoice_no"];
                 NSString *proformaInvoiceDate = [response valueForKey:@"proforma_invoice_date"];
                 NSString *plannedShipmentDates = [response valueForKey:@"planned_shipment_dates"];
                 NSString *pointOfContact =[[response objectForKey:@"point_of_contact"] valueForKey:@"empid"];
                 NSString *pendingStatus = [response valueForKey:@"status"];
                 NSDictionary *productName = [response valueForKey:@"products"];
                 NSDictionary *quantity = [response valueForKey:@"quantity"];
                 NSDictionary *rate = [response valueForKey:@"rate"];
                 NSDictionary *amount = [response valueForKey:@"amount"];
                 NSDictionary *productImages = [response valueForKey:@"product_image"];
                 NSDictionary *point_of_contact = [response valueForKey:@"point_of_contact"];

                 NSString *qty;
                 NSString *rte;
                 NSString *img;
                 NSString *address;
                 NSString *name;
                 NSString *amt;

                 for (int i = 0; i < [productName count]; i++) 
                     //  NSLog(@"product name %@",[productName valueForKey:[NSString stringWithFormat:@"%d",i ]]);
                     name = [productName valueForKey:[NSString stringWithFormat:@"%d",i ]];
                 

                 for (int i = 0; i < [quantity count]; i++) 
                     //  NSLog(@"quantity %@",[quantity valueForKey:[NSString stringWithFormat:@"%d",i ]]);
                     qty = [quantity valueForKey:[NSString stringWithFormat:@"%d",i ]];
                 

                 for (int i = 0; i < [rate count]; i++) 
                     //  NSLog(@"rate %@",[rate valueForKey:[NSString stringWithFormat:@"%d",i ]]);
                     rte = [rate valueForKey:[NSString stringWithFormat:@"%d",i ]];
                 

                 for (int i = 0; i < [amount count]; i++) 
                     // NSLog(@"amount %@",[amount valueForKey:[NSString stringWithFormat:@"%d",i ]]);
                     amt = [amount valueForKey:[NSString stringWithFormat:@"%d",i ]];
                 


                 for (int i = 0; i < [productImages count]; i++) 
                     // NSLog(@"product image %@",[productImages valueForKey:[NSString stringWithFormat:@"%d",i ]]);
                     img = [productImages valueForKey:[NSString stringWithFormat:@"%d",i ]];
                 

                 for (int i = 0; i < [point_of_contact count]; i++) 
                     //  NSLog(@"pt of ct %@",[point_of_contact valueForKey:[NSString stringWithFormat:@"empid" ]]);
                     address = [point_of_contact valueForKey:[NSString stringWithFormat:@"empid" ]];
                 


                 NSManagedObjectContext *context = [self managedObjectContext];

                 //update
                 if((self.pendingShipmentDAO) ) 
                     NSLog(@"update");
                     [self.pendingShipmentDAO setValue:shipmentNumber forKey:@"shipmentno"];
                     [self.pendingShipmentDAO setValue:proformaInvoiceNumber forKey:@"proforma_invoice_no"];
                     [self.pendingShipmentDAO setValue:proformaInvoiceDate forKey:@"proforma_invoice_date"];
                     [self.pendingShipmentDAO setValue:invoiceNo forKey:@"invoice_no"];
                     [self.pendingShipmentDAO setValue:invoiceDate forKey:@"invoice_date"];
                     [self.pendingShipmentDAO setValue:plannedShipmentDates forKey:@"planned_shipment_date"];
                     [self.pendingShipmentDAO setValue:address forKey:@"point_of_contact"];
                     [self.pendingShipmentDAO setValue:address forKey:@"empid"];
                     [self.pendingShipmentDAO setValue:name forKey:@"products"];
                     [self.pendingShipmentDAO setValue:qty forKey:@"quantity"];
                     [self.pendingShipmentDAO setValue:rte forKey:@"rate"];
                     [self.pendingShipmentDAO setValue:amt forKey:@"amount"];
                     [self.pendingShipmentDAO setValue:img forKey:@"product_image"];
                     [self.pendingShipmentDAO setValue:pendingStatus forKey:@"status"];
                 else 

                     NSLog(@"create");

                     NSManagedObject *pendingShipment = [NSEntityDescription insertNewObjectForEntityForName:@"PendingShipmentDetails" inManagedObjectContext:context];

                     // [self deleteAllPreviousData];
                     [pendingShipment setValue:shipmentNumber forKey:@"shipmentno"];
                     [pendingShipment setValue:proformaInvoiceNumber forKey:@"proforma_invoice_no"];
                     [pendingShipment setValue:proformaInvoiceDate forKey:@"proforma_invoice_date"];
                     [pendingShipment setValue:invoiceNo forKey:@"invoice_no"];
                     [pendingShipment setValue:invoiceDate forKey:@"invoice_date"];
                     [pendingShipment setValue:plannedShipmentDates forKey:@"planned_shipment_date"];
                     [pendingShipment setValue:address forKey:@"point_of_contact"];
                     [pendingShipment setValue:address forKey:@"empid"];
                     [pendingShipment setValue:name forKey:@"products"];
                     [pendingShipment setValue:qty forKey:@"quantity"];
                     [pendingShipment setValue:rte forKey:@"rate"];
                     [pendingShipment setValue:amt forKey:@"amount"];
                     [pendingShipment setValue:img forKey:@"product_image"];
                     [pendingShipment setValue:pendingStatus forKey:@"status"];


                 
             
         

         else if ([data length] == 0 && connectionError == nil)
         
             [self emptyReply];
         
         else if (connectionError != nil && connectionError.code == NSURLErrorTimedOut)
         
             [self timedOut];
         
         else if (connectionError != nil)
         
             [self downloadError:connectionError];
         
     ];

【问题讨论】：

显示类声明（@interface位）；在某处一定有一个@property SomeType *pendingShipmentDetails;...

@interface MyOrdersController () @property (strong) NSMutableArray *devices; @end

【参考方案1】：

点符号用于属性（获取或设置）它们。所以这里编译器知道你想调用pendingShipmentDetails的getter，但事实并非如此。您必须使用[] 来调用方法。将apiRequest.pendingShipmentDetails 替换为[apiRequest pendingShipmentDetails]，警告应该会消失。

【讨论】：

行得通。你能帮我纠正第二个错误吗？

else 循环正在执行两次

“你想调用setter”你的意思是getter也许吗？

我实际上是在解析 json 并将这些内容添加到核心数据的实体中。然后，我创建一个 NSManagedObject 实例，如果以前不存在这样的实例。如果它存在，我试图用新获取的数据更新实体，但它没有发生。 :(

self.pendingShipmentDAO的值在哪里设置？