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我有一个 UITableViewController 用于显示本地业务对象列表的名称。我用过这个 UITableViewController
以前从 .csv 文件中读取信息，这一切都正常工作，并在我的 UITableViewController 中完美地显示了业务名称。
但是，我最近已将所有这些信息移至 Parse.com，现在我正在尝试在我当前的 UITableViewController 中读取和显示来自 Parse.com 的信息。
我正在尝试重构代码，而不是在这里使用 Parse.com 的教程:
https://www.parse.com/docs/ios_guide#ui-tables/iOS
在我的 viewDidLoad 方法中，我调用自己的方法 [self initializeContent] 执行 PFQuery 以检索适合的对象列表一定的标准，然后将对象保存在 NSMutableArray 中。
这执行得很好，我可以看到业务对象正在通过我的 [self initializeContent] 方法中的 NSLogs 检索并保存到 NSMutableArray(数据数组)。
但是，在单步执行代码时，我的 dataArray 在 numberOfSectionsInTableView 方法中为 0。因此，我没有看到 UITableViewController 中显示的业务名称。
numberOfSectionsInTableView 是否在 viewDidLoad 方法之前执行，这意味着我的 dataArray 将始终为 0？
我已单步执行代码，但无法弄清楚我的问题出在哪里。
以下是我的代码 - 我已尽可能多地包含在内，以帮助确定我的问题所在。
BusinessDetailTableViewController.h
#import <UIKit/UIKit.h>
#import < arse/Parse.h>
@interface BusinessDetailTableViewController : UITableViewController
@property (nonatomic, strong) NSMutableArray *dataArray;
@property (nonatomic, strong) NSMutableArray *defaultBusinessArrayMutable;
@property (nonatomic, assign) int tagNumber;
@property (nonatomic, strong) NSString *className;
@end
BusinessDetailTableViewController.m
#import "BusinessDetailTableViewController.h"
#import "BusinessDetailContent.h"
#import "DetailViewController.h"
#import <arse/Parse.h>
@interface BusinessDetailTableViewController ()
@end
@implementation BusinessDetailTableViewController
@synthesize dataArray;
@synthesize defaultBusinessArrayMutable;
@synthesize tagNumber;
@synthesize className;
- (void)viewDidLoad
{
[super viewDidLoad];
[self initializeArrays];
[self initializeContent];
}
- (void) initializeArrays
{
dataArray = [[NSMutableArray alloc] init];
defaultBusinessArrayMutable = [[NSMutableArray alloc] init];
}
- (void) initializeContent
{
NSLog(@"Class Name: %@", className); // Shows the correct className
[self queryParse:className];
}
- (void) queryParse NSString *) className
{
PFQuery *query = [PFQuery queryWithClassName:self.className];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error)
{
if (!error)
{
NSLog(@"Successfully Retrieved %d Objects.", (int)objects.count); // Shows how many objects are retrieved
for (PFObject *object in objects)
{
BusinessDetailContent *businessDetailContent = [[BusinessDetailContent alloc] init];
businessDetailContent.no = object[@"ID"];
businessDetailContent.companyName = object[@"Company_Name"];
businessDetailContent.address = object[@"Address"];
businessDetailContent.tel = object[@"Tel"];
businessDetailContent.email = object[@"Email"];
businessDetailContent.website = object[@"Website"];
businessDetailContent.details = object[@"Details"];
businessDetailContent.imageName = object[@"Image_ID"];
// The information here is retrieved correctly
NSLog(@"BUSINESS DETAIL CONTENT - ID: %@, Company Name: %@, Address: %@, Tel: %@, Email: %@, Website: %@, Details: %@, Image_Name: %@",
businessDetailContent.no, businessDetailContent.companyName, businessDetailContent.address, businessDetailContent.tel,
businessDetailContent.email, businessDetailContent.website, businessDetailContent.details,
businessDetailContent.imageName);
[defaultBusinessArrayMutable addObject:businessDetailContent];
NSString *strFromInt = [NSString stringWithFormat "%d", tagNumber];
if (!([strFromInt isEqualToString"3"] || [strFromInt isEqualToString"10"]))
{
[dataArray addObject:defaultBusinessArrayMutable];
NSLog(@"Default Business Array Mutable Count: %i", (int)dataArray.count);
}
}
}
}
else
{
NSLog(@"Error retrieving objects: %@ %@", error, [error userInfo]);
}
}];
}
- (UITableViewCell *)tableViewUITableView *)tableView cellForRowAtIndexPathNSIndexPath *)indexPath
{
NSLog(@" cellForRowAtIndexPath "); // This is not executed
static NSString *CellIdentifier = @"Cell";
NSLog(@"Cell Identifier: %@", CellIdentifier);
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell
NSArray *cellArray = [dataArray objectAtIndex:indexPath.section];
BusinessDetailContent *businessDetailContent = [cellArray objectAtIndex:indexPath.row];
cell.textLabel.text = businessDetailContent.companyName;
NSLog(@"Cell Textlabel Text: %@", cell.textLabel.text);
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
- (void) tableViewUITableView *)tableView didSelectRowAtIndexPathNSIndexPath *)indexPath
{
NSLog(@" didSelectRowAtIndexPath ");
[self performSegueWithIdentifier"businessDetailSegue" sender:self];
}
- (NSInteger) numberOfSectionsInTableViewUITableView *)tableView
{
NSLog(@"numberOfRowsInSection returning: %d", (int)[dataArray count]);
return [dataArray count]; // dataArray = 0
}
- (NSInteger)tableViewUITableView *)tableView numberOfRowsInSectionNSInteger)section
{
NSMutableArray *array = [dataArray objectAtIndex:section];
return [array count];
}
- (void) prepareForSegueUIStoryboardSegue *)segue senderid)sender
{
NSLog(@"repareForSegue: %@", segue.identifier);
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
if ([segue.identifier isEqualToString"businessDetailSegue"] && indexPath)
{
NSArray *selectedRowArray = [dataArray objectAtIndex:indexPath.section];
BusinessDetailContent *selectedContent = [selectedRowArray objectAtIndex:indexPath.row];
DetailViewController *detailController = segue.destinationViewController;
detailController.businessDetailContent = selectedContent;
}
}a
@end
编辑:我添加了 [self.tableView reloadData];正如许多人所建议的那样，到我的 findObjectsInBackgroundWithBlock 方法结束，现在我正在使用 numberOfSectionsInTableView 方法，但 dataArray 仍然是 0。看起来我的代码执行了两次，可以通过控制台打印看到？
对于我的 queryParse 方法中的 dataArray，它返回 18 个对象 - 但应该只有 9 个。
从控制台打印 Hotel Array Count 从 2 开始，之后每次增加 2。
我的 numberOfRowsInSection 现在被执行了两次，但在 Parse.com 查询之前。
我完全被这个困住了。
Best Answer-推荐答案
@Hans Moolman，是的，你是对的，你只需要在解析完成后调用 table view 的 reload 方法。即。
- (NSMutableArray *) queryParse:(NSString *) className
{
PFQuery *query = [PFQuery queryWithClassName:self.className];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error)
{
if (!error)
{
NSLog(@"Successfully Retrieved %d Objects.", (int)objects.count); // Shows how many objects are retrieved
for (PFObject *object in objects)
{
BusinessDetailContent *businessDetailContent = [[BusinessDetailContent alloc] init];
businessDetailContent.no = object[@"ID"];
businessDetailContent.companyName = object[@"Company_Name"];
businessDetailContent.address = object[@"Address"];
businessDetailContent.tel = object[@"Tel"];
businessDetailContent.email = object[@"Email"];
businessDetailContent.website = object[@"Website"];
businessDetailContent.details = object[@"Details"];
businessDetailContent.imageName = object[@"Image_ID"];
// The information here is retrieved correctly
NSLog(@"BUSINESS DETAIL CONTENT - ID: %@, Company Name: %@, Address: %@, Tel: %@, Email: %@, Website: %@, Details: %@, Image_Name: %@",
businessDetailContent.no, businessDetailContent.companyName, businessDetailContent.address, businessDetailContent.tel,
businessDetailContent.email, businessDetailContent.website, businessDetailContent.details,
businessDetailContent.imageName);
[defaultBusinessArrayMutable addObject:businessDetailContent];
NSString *strFromInt = [NSString stringWithFormat"%d", tagNumber];
if (!([strFromInt isEqualToString"3"] || [strFromInt isEqualToString"10"]))
{
[dataArray addObject:defaultBusinessArrayMutable];
NSLog(@"Default Business Array Mutable Count: %i", (int)dataArray.count);
}
}
}
}
else
{
NSLog(@"Error retrieving objects: %@ %@", error, [error userInfo]);
}
}];
// This line to be added
[self.tableView reloadData];
}
如果仍然存在问题，请告诉我。谢谢。
关于ios - 数组在 numberOfRowsInSection 中等于 0，我们在Stack Overflow上找到一个类似的问题：
https://stackoverflow.com/questions/24672643/
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