为NsObject键 - 表达式不可分配添加值
我正在尝试添加一个从API调用到Objective-C中的对象的值。我在Xcode中遇到了一个错误，说“表达是不可分配的”，不明白为什么。在我的carobj中，我有一个名为保证计划的对象，带有nil值，我正在尝试为prants> prants> prants> prants> prants> prants> pranantsplan value设置值代码>。我在这种方法中做错了什么？
NSArray *carUUIDs = [carData valueForKeyPath:@"uuid"];
NSString *ownerUUID = ownerRecord[@"uuid"];
if (ownerID) {
NSManagedObjectContext *context = [DataCenter viewContext];
NSObject *carObj = [context objectsForEntityName:[CarObject entityName] matchingUUIDs:carUUIDs];
for (id carID in carUUIDs){
[WarrantyPlansService getWarrantyPlansForCarWithCarID:carID ownerID:ownerUUID completion:^(NSArray* response, NSError* error){
//attach the response to the carData
NSLog(@"%@", [carObj valueForKeyPath:@"warrantyPlans"]);
[carObj valueForKeyPath:@"warrantyPlans"] = response;
}];
}
I’m trying to add a value I get back from an API call to an object in Objective-C. I get an error in Xcode saying “Expression is not assignable” and don’t understand why. In my carObj I have an object called warrantyPlan with a nil value and I’m trying to set the value for warrantyPlan. What am I doing wrong in this method?
NSArray *carUUIDs = [carData valueForKeyPath:@"uuid"];
NSString *ownerUUID = ownerRecord[@"uuid"];
if (ownerID) {
NSManagedObjectContext *context = [DataCenter viewContext];
NSObject *carObj = [context objectsForEntityName:[CarObject entityName] matchingUUIDs:carUUIDs];
for (id carID in carUUIDs){
[WarrantyPlansService getWarrantyPlansForCarWithCarID:carID ownerID:ownerUUID completion:^(NSArray* response, NSError* error){
//attach the response to the carData
NSLog(@"%@", [carObj valueForKeyPath:@"warrantyPlans"]);
[carObj valueForKeyPath:@"warrantyPlans"] = response;
}];
}
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[Carobj valueforkeypath：@“ warrantyplans”]是 expression ，其具有类似于42的值是具有值的表达式。它不是foo的表达式，它的变量为42，可以通过在平等符号的左侧使用它来更改。要更改它，您想要：
[Carobj SetValue：响应forkeypath：@“ prantyplans”]这两个称为通用 getter
valueforkey：and code>通用 settersetValue：forkey：在KEYVALUECODING指南中： https://developer.apple.com/library/archive/archive/documentation/cocoa/cocoa/coneptual/coneptual/keyvaluecoding/index.htex.html[carObj valueForKeyPath:@"warrantyPlans"]is an expression that has a value like literally42is an expression that has a value. It's not an expression likefoothat is a variable that has a value of 42 and can be changed by using it on the left hand side of an equals sign.To change it you want:
[carObj setValue:response forKeyPath:@"warrantyPlans"]These two are called the generic getter
valueForKey:and the generic settersetValue:forKey:in the KeyValueCoding guide: https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/KeyValueCoding/index.html