Question

我是iOS的新手，我面临着在Core数据中保存数组重新生成数据的问题。如图所示

我从表格视图中选择了一个按钮，它在核心数据中保存了值

为此，我的代码就像这样

 NSString *FailString=@"";
    NSString *WarningString=@"";

    NSManagedObjectContext *context = [self managedObjectContext];
    NSError *error;

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    [request setEntity:[NSEntityDescription entityForName:@"AuditPost" inManagedObjectContext:context]];

    //  NSError *error = nil;
    NSArray *results = [context executeFetchRequest:request error:&error];
    NSLog(@"Result =%@",results);

    int imageSize   = imgData.length;
    NSLog(@"size of image in KB: %d ", imageSize/1024);
    int OCS=imageSize/1024;

    NSLog(@"OCS Image Size =%d",OCS);

    if(OCS<2)
    {
        AuditImageString=@"";
    }

    ComplareArray=[devices valueForKey:@"checkpointid"];

    BOOL contains = [ComplareArray containsObject:String2];

    if(contains == NO)
    {
        if (self.device) {
            // Update existing device
            [device setValue:Audit forKey:@"auditnameId"];
            [device setValue:String forKey:@"checklistid"];
            [device setValue:String2 forKey:@"checkpointid"];
            [device setValue:FailString forKey:@"failreason"];
            [device setValue:WarningString forKey:@"warningreason"];
            [device setValue:AuditStartDate forKey:@"starttimedate"];
            [device setValue:userid forKey:@"userid"];
            [device setValue:AuditImageString forKey:@"auditimage"];

            NSError *error = nil;
            // Save the object to persistent store
            if (![context save:&error]) {
                NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
            }

        } else {
            // Create a new device
            NSManagedObject *newDevice = [NSEntityDescription insertNewObjectForEntityForName:@"AuditPost" inManagedObjectContext:context];
            [newDevice setValue:Audit forKey:@"auditnameId"];
            [newDevice setValue:String forKey:@"checklistid"];
            [newDevice setValue:String2 forKey:@"checkpointid"];
            [newDevice setValue:FailString forKey:@"failreason"];
            [newDevice setValue:WarningString forKey:@"warningreason"];
            [newDevice setValue:AuditStartDate forKey:@"starttimedate"];
            [newDevice setValue:userid forKey:@"userid"];
            [newDevice setValue:AuditImageString forKey:@"auditimage"];

            NSError *error = nil;
            // Save the object to persistent store
            if (![context save:&error]) {
                NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
            }
        }
    }
    else
    {
        NSError *error = nil;
        // Save the object to persistent store
        if (![context save:&error]) {
            NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
        }

        NSManagedObjectContext *context = [self managedObjectContext];

        NSFetchRequest *request = [[NSFetchRequest alloc] init];
        [request setEntity:[NSEntityDescription entityForName:@"AuditPost" inManagedObjectContext:context]];

        NSArray *results = [context executeFetchRequest:request error:&error];
        NSManagedObject* favoritsGrabbed = [results objectAtIndex:CurrentIndexPath];
        [favoritsGrabbed setValue:String forKey:@"checklistid"];
        // Save the object to persistent store
        if (![context save:&error]) {
            NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
        }
    }

    //example reload table
    dispatch_async(dispatch_get_main_queue(), ^{
        [Audittable reloadData];
    });

要将整个数组保存在核心数据中，我使用的代码如下

if (self.device)
            {
                // Update existing device
                [device setValue:Audit forKey:@"auditnameId"];
                [device setValue:[NSString stringWithFormat:@"%@",Passarray[i]] forKey:@"checklistid"];
                [device setValue:[NSString stringWithFormat:@"%@",CheckpointNameIDArray[i]] forKey:@"checkpointid"];
                [device setValue:FailString forKey:@"failreason"];
                [device setValue:WarningString forKey:@"warningreason"];
                [device setValue:AuditStartDate forKey:@"starttimedate"];
                [device setValue:userid forKey:@"userid"];
                [device setValue:[NSString stringWithFormat:@"%@",AuditImageString] forKey:@"auditimage"];
                NSError *error = nil;
                // Save the object to persistent store
                if (![context save:&error]) {
                    NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
                }
            }
            else
            {
                // Create a new device
                NSManagedObject *newDevice = [NSEntityDescription insertNewObjectForEntityForName:@"AuditPost" inManagedObjectContext:context];
                [newDevice setValue:Audit forKey:@"auditnameId"];
                [newDevice setValue:[NSString stringWithFormat:@"%@",Passarray[i]] forKey:@"checklistid"];
                [newDevice setValue:[NSString stringWithFormat:@"%@",CheckpointNameIDArray[i]] forKey:@"checkpointid"];
                [newDevice setValue:FailString forKey:@"failreason"];
                [newDevice setValue:WarningString forKey:@"warningreason"];
                [newDevice setValue:AuditStartDate forKey:@"starttimedate"];
                [newDevice setValue:userid forKey:@"userid"];
                [newDevice setValue:[NSString stringWithFormat:@"%@",AuditImageString] forKey:@"auditimage"];

                NSError *error = nil;
                // Save the object to persistent store
                if (![context save:&error]) {
                    NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
                }
             }
            }
            for (int i=0; i<PassarrIndexPaths.count; i++)
            {
                AuditNextTableViewCell *cell = [Audittable cellForRowAtIndexPath:[PassarrIndexPaths objectAtIndex:i]];
                DataModel *model = [arrData objectAtIndex:i];
                model.strSelected = @"P";
                [cell.passbtn setBackgroundColor:[UIColor greenColor]];
                [cell.failbtn setBackgroundColor:[UIColor lightGrayColor]];
                [cell.wipbtn setBackgroundColor:[UIColor lightGrayColor]];
                [cell.nabtn setBackgroundColor:[UIColor lightGrayColor]];
            }
//            Passbtn.backgroundColor=[UIColor greenColor];
//            NAbtn.backgroundColor=[UIColor lightGrayColor];
            [Audittable reloadData];

与图像一样如果我单击Mark Pending As PASS，它会将核心数据中的重新数组元素保存为非选择。对于选择，我使用的代码是这样的

NSManagedObjectContext *managedObjectContext = [self managedObjectContext];
            NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"AuditPost"];
            self.devices = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy];

            for (int i=0; i<PassarrIndexPaths.count; i++)
            {
                AuditNextTableViewCell *cell = [Audittable cellForRowAtIndexPath:[PassarrIndexPaths objectAtIndex:i]];
                DataModel *model = [arrData objectAtIndex:i];

                if([model.strSelected isEqualToString:@"P"])
                {

                }
                else if ([model.strSelected isEqualToString:@"W"])
                {

                }
                else if ([model.strSelected isEqualToString:@"F"])
                {

                }
                else if ([model.strSelected isEqualToString:@"NA"])
                {

                }
                else if ([model.strSelected isEqualToString:@"NAA"])
                {

                }
                else
                {
                    model.strSelected = @"PA";
                    [cell.passbtn setBackgroundColor:[UIColor greenColor]];
                    [cell.failbtn setBackgroundColor:[UIColor lightGrayColor]];
                    [cell.wipbtn setBackgroundColor:[UIColor lightGrayColor]];
                    [cell.nabtn setBackgroundColor:[UIColor lightGrayColor]];
                }

我面临的问题是，如果我在核心数据中保存一些数据那么。如何在核心数据中保存数组的重新数据。如果有人这样做了。感谢Adnavce！

Answer 1

如果我是正确的你想要保存数据对象数据库中尚不存在哪个对象那么简单，

-(void)save_UpdateData:(NSArray *)yourArray {

    NSManagedObjectContext *_context = [self getManagedObjectContext];

     for(int i = 0; i < [yourArray count]; i++) {
        NSDictionary *details = [yourArray objectAtIndex:i];
        NSArray *_arrayMappingObjects = [self getSavedDataFromDB];
        //Lets check mapping object exist in current record or not.
        //If not exist then create new one and add the same
        //If already exist, No need to add.
        NSPredicate *_predicate = [NSPredicate predicateWithFormat:@"yourKey_predicate_id=%@",[NSNumber numberWithInt:[[details objectForKey:@"yourKey_predicate_id"] intValue]]];
        _arrayMappingObjects = [_arrayMappingObjects filteredArrayUsingPredicate:_predicate];
        if([_arrayMappingObjects count] > 0) {

          //Object already exist, No need to add the same object.

        } else {
            // Lets create an object add newly created instance
            ModelClass *modelObject = [NSEntityDescription insertNewObjectForEntityForName:@"ModelClass" inManagedObjectContext:_context];
            [modelObject setEntityName1:[details objectForKey:@"key1"]];//If your property is NSString
            [modelObject setEntityName2:[NSNumber numberWithInt:[[details objectForKey:@"key2"] intValue]]];//If your property is NSNumber
            [modelObject setEntityName3:[NSNumber numberWithInt:[[details objectForKey:@"key3"] intValue]]];

            [self saveContext];
        }
    }
}

//获取保存的数据

-(NSMutableArray *)getSavedDataFromDB {

    NSMutableArray *_record = [[NSMutableArray alloc] initWithCapacity:0];

    NSManagedObjectContext *_context =[self getManagedObjectContext];
    NSFetchRequest *_fetchRequest = [[NSFetchRequest alloc]init];
    NSEntityDescription *_entityDesc =[NSEntityDescription entityForName:@"ModelClass" inManagedObjectContext:_context];
    [_fetchRequest setEntity:_entityDesc];

    NSError *_error;
    NSArray *_fetchedOjects = [_context executeFetchRequest:_fetchRequest error:&_error];

    for(int i=0;i<[_fetchedOjects count];i++) {
        ModelClass *modelObject = [_fetchedOjects objectAtIndex:i];
        [_record addObject:modelObject];
    }
    return _record;
}

如何在Objective C中保存核心数据中数组的重新生成数据

1 个答案: