我不明白为什么我得到 '此查询具有出色的网络连接。你必须等到它完成。
因为我只运行一个查询任何人都可以帮忙，因为我是新手解析
- (id)initWithCoder:(NSCoder *)aCoder {
self = [super initWithCoder:aCoder];
if (self) {
// Customize the table
// The className to query on
self.parseClassName = @"Exibitor";
// The key of the PFObject to display in the label of the default cell style
self.textKey = @"name";
// Uncomment the following line to specify the key of a PFFile on the PFObject to display in the imageView of the default cell style
// self.imageKey = @"image";
// Whether the built-in pull-to-refresh is enabled
self.pullToRefreshEnabled = YES;
// Whether the built-in pagination is enabled
self.paginationEnabled = YES;
// The number of objects to show per page
self.objectsPerPage = 25;
}
return self;
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
//self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[super viewDidAppear:animated];
self.canDisplayBannerAds = YES;
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - Parse
- (void)objectsDidLoad:(NSError *)error {
[super objectsDidLoad:error];
// This method is called every time objects are loaded from Parse via the PFQuery
}
- (void)objectsWillLoad {
[super objectsWillLoad];
// This method is called before a PFQuery is fired to get more objects
}
// Override to customize what kind of query to perform on the class. The default is to query for
// all objects ordered by createdAt descending.
- (PFQuery *)queryForTable {
PFQuery *query = [PFQuery queryWithClassName:@"Exibitor"];
[query whereKey:@"Trade" equalTo:@"true"];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (!object) {
NSLog(@"The getFirstObject request failed.");
} else {
// The find succeeded.
NSLog(@"Successfully retrieved the object.");
}
}];
return query;
}
// Override to customize the look of a cell representing an object. The default is to display
// a UITableViewCellStyleDefault style cell with the label being the first key in the object.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell
cell.textLabel.text = [object objectForKey:@"text"];
cell.detailTextLabel.text = [NSString stringWithFormat:@"name: %@", [object objectForKey:@"name"]];
return cell;
}
/*
// Override if you need to change the ordering of objects in the table.
- (PFObject *)objectAtIndex:(NSIndexPath *)indexPath {
return [objects objectAtIndex:indexPath.row];
}
*/
/*
// Override to customize the look of the cell that allows the user to load the next page of objects.
// The default implementation is a UITableViewCellStyleDefault cell with simple labels.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForNextPageAtIndexPath: (NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"NextPage";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.textLabel.text = @"Load more...";
return cell;
}
*/
#pragma mark - Table view data source
/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
*/
/*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle: (UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
*/
/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/
/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the item to be re-orderable.
return YES;
}
*/
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[super tableView:tableView didSelectRowAtIndexPath:indexPath];
}
@end
任何人都可以帮忙解决这个问题我是新来解析的，而且我已经完成了，因为它告诉我在文档中
答案 0 :(得分：5)
在方法queryForTable中，您不应该执行查询，只能配置并返回它。
- (PFQuery *)queryForTable {
PFQuery *query = [PFQuery queryWithClassName:@"Exibitor"];
[query whereKey:@"Trade" equalTo:@"true"];
return query;
}
您正在执行查询，这会导致您遇到的行为，因为表控制器也在尝试执行它。
答案 1 :(得分：1)
PFObject不允许同时对给定对象发出多个网络请求。
只要同时调用同一对象的saveInBackground，getDataInBackground或fetchInBackground，就会发生这种情况。这些方法用于处理异步工作流，但不应同时调用。这些检查旨在帮助开发人员，因为同时下载同一资源只会对应用程序的性能产生负面影响。
此外，如果应用程序可互换地使用两个不同版本的数据，则这两个提取可能下载不同数据（即服务器上的PFObject在调用之间发生更改）的可能性可能会导致应用程序中的细微且痛苦的错误。
您可以使用这些异步函数提供的回调方法或块来确定网络操作何时完成。如果异步保存操作不需要回调，您可能还需要考虑使用saveEventually。您可以在同一个对象上多次调用saveEventually，我们会为您排队等待这些操作。