Question

我试图弄清楚如何搜索/查询PFObject而不是用户。这是我迄今为止所做的和它的发现，但没有显示。我找到this post并跟着它，但没有达到运行结果，因为它没有显示结果。我无法弄清楚如何展示PFObject，以便我需要帮助：）

-(void)filterResults:(NSString *)searchTerm {

    [self.searchResults removeAllObjects];

    PFQuery *query = [PFQuery queryWithClassName:@"New"];
    [query whereKeyExists:@"by"];  //this is based on whatever query you are trying to accomplish
    [query whereKeyExists:@"title"]; //this is based on whatever query you are trying to accomplish
    [query whereKey:@"title" containsString:searchTerm];

    NSArray *results  = [query findObjects];

    NSLog(@"%@", results);
   // NSLog(@"%u", results.count);

    [self.searchResults addObjectsFromArray:results];
}

然后我试图在这里显示：

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {

       static NSString *CellIdentifier = @"Cell";
   PFTableViewCell *cell = (PFTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];   


    if (cell == nil) {
        cell = [[PFTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }


    cell.textLabel.text = [object objectForKey:self.textKey];



    if (tableView != self.searchDisplayController.searchResultsTableView) {

      /*  PFObject *title = [PFQuery queryWithClassName:@"title"];
        PFQuery *query = [PFQuery queryWithClassName:@"New"];
        PFObject *searchedUser = [query getObjectWithId:title.objectId]; NSString * usernameString = [searchedUser objectForKey:@"title"]; cell.textLabel.text = [NSString stringWithFormat:@"%@", usernameString];
       */
        PFQuery *query = [PFQuery queryWithClassName:@"New"];
        [query whereKey:@"title" equalTo:@"by"];
        [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
            if (!error) {
                // The find succeeded.
                NSLog(@"Successfully retrieved %d title", objects.count);
                // Do something with the found objects
                for (PFObject *object in objects) {
                    NSLog(@"%@", object.objectId);
                }
            } else {
                // Log details of the failure
                NSLog(@"Error: %@ %@", error, [error userInfo]);
            }
        }];


    }
    if ([tableView isEqual:self.searchDisplayController.searchResultsTableView]) {

        PFQuery *query = [PFQuery queryWithClassName:@"New"];
        [query whereKey:@"title" equalTo:@"by"];
        [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
            if (!error) {
                // The find succeeded.
                NSLog(@"Successfully retrieved %d title", objects.count);
                // Do something with the found objects
                for (PFObject *object in objects) {
                    NSLog(@"%@", object.objectId);
                }
            } else {
                // Log details of the failure
                NSLog(@"Error: %@ %@", error, [error userInfo]);
            }
        }];

       /* //PFObject *obj2 = [self.searchResults objectAtIndex:indexPath.row];
        PFQuery *query = [PFQuery queryWithClassName:@"New"];
        PFObject *searchedUser = [query getObjectWithId:obj2.objectId];
        NSString *first = [searchedUser objectForKey:@"title"];
        NSString *last = [searchedUser objectForKey:@"by"];
        cell.textLabel.text = [first substringToIndex:1];
        NSString *subscript = last;
       // cell.categoryName.text = [searchedUser objectForKey:@"category"];
        */
    }
    return cell;

}

Answer 1

您的代码所做的是，首先，在filterResults中，您将检索包含字段“by”和字段“title”以及“title”包含searchTerm的所有对象。

然后，当你创建一个单元格时，你会做另一个查询（你永远不应该这样做，因为它现在有一个持久的操作来处理所显示的每个单元格。滚动这个视图永远不会工作。除此之外;您正在将标题与字符串@“by”进行比较，我非常确定这不是您的意图。

因此，您的主要问题在于您构建查询的方式，而您的第二个问题是您正在为每个单元格执行此操作。

您需要做的是在第一次搜索时获取所需的所有数据，然后在显示时迭代这些数据。

类似的东西：

- (void)viewDidLoad {        
        PFQuery *query = [PFQuery queryWithClassName:@"TestClass"];
        query.cachePolicy = kPFCachePolicyNetworkOnly;
        query.limit = 50;
        [query whereKey:@"city" equalTo:chosenCity];
        [query whereKey:@"sex" equalTo:@"female"];
        [query findObjectsInBackgroundWithTarget:self selector:@selector(callbackLoadObjectsFromParse:)];

    - (void)callbackLoadObjectsFromParse:(NSArray *)result error:(NSError *)error {
        if (!error) {
            NSLog(@"Successfully fetched %d entries", result.count);

            self.allTestObjects = result;
        } else {
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
    }

然后，稍后在cellForRowAtIndexPath中使用此数组（不再查询）作为数据的数据源：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
        static NSString *CellIdentifier = @"Cell";
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    PFObject * testObject = [self.allTestObjects objectAtIndex:indexPath.row],
    cell.textLabel.text = [testObject objectForKey:@"name"];

    return cell;
    }

使用数据库时，永远不要在tableviewcells中进行查找。首先准备好您的数据，然后以最佳性能呈现它们。

如何搜索PFObject UITableView

1 个答案: