Question

在我的应用程序中，我解析了一个XML文件，然后我想在UITableView中显示该文件的条目。我在web上找到了如何按字母顺序排列部分（比如iPhone联系人），它适用于我的应用程序。当我点击我的tableview中的一行时，我想显示另一个ViewController，我会在其中找到有关我所点击的行的一些信息，但我遇到了一些问题：当我点击一行变量indexPath.row时指的是新视图控制器中的部分和信息不正确。我将在这里发布一些截图，表明你想要我解释一下。

在下面的图片中，您可以看到该应用的运作方式：

Correct

在以下图片中，您可以看到我的应用程序的错误：

error

你可以看到图1中的名字是相同的，在图2中你可以看到它的名字是错的。我想这取决于变量indexPath.row。我将在这里发布代码来创建和填充tableview：

#import "TableWasteViewController.h"
#import "WasteXmlParser.h"
#import "WasteDetailViewController.h"

@interface TableWasteViewController ()

@property(nonatomic,strong)NSArray *arrayWastes;
@property(nonatomic,strong)NSMutableArray *typeOfWaste;
@property(nonatomic,strong)NSMutableArray *typeOfBin;
@property(nonatomic,strong)NSMutableArray *indexWastes;
@property(nonatomic,strong)NSMutableArray *typeOfWasteBackup;

@end

@implementation TableWasteViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    WasteXmlParser *parser = [[WasteXmlParser alloc]init];
    [parser parseWasteXml];
    self.arrayWastes = [[NSArray alloc]init];
    self.arrayWastes = [parser.arrayWastes mutableCopy];
    self.indexWastes = [[NSMutableArray alloc]init];
    self.typeOfWaste = [[NSMutableArray alloc]init];
    self.typeOfBin = [[NSMutableArray alloc]init];
    for (int i = 0; i < [self.arrayWastes count]; i++) {
        [self.typeOfWaste addObject:[[self.arrayWastes objectAtIndex:i] objectForKey:@"type"]];
        [self.typeOfBin addObject:[[self.arrayWastes objectAtIndex:i]objectForKey:@"place"]];
    }
    for (int i = 0; i < [self.typeOfWaste count]-1; i++) {
        char alphabet = [[self.typeOfWaste objectAtIndex:i] characterAtIndex:0];
        NSString *uniChar = [NSString stringWithFormat:@"%c", alphabet];
        if (![self.indexWastes containsObject:uniChar]) {
            [self.indexWastes addObject:uniChar];
        }
    }
    self.typeOfWasteBackup = [self.typeOfWaste mutableCopy];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [self.indexWastes count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    return [self.indexWastes objectAtIndex:section];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSString *alphabet = [self.indexWastes objectAtIndex:section];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] %@",alphabet];
    NSArray *wastes = [self.typeOfWaste filteredArrayUsingPredicate:predicate];

    return [wastes count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    UIFont *myFont = [UIFont fontWithName:@"Arial" size:14.0];
    if (cell == nil) {
         cell  = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    NSString *alphabet = [self.indexWastes objectAtIndex:[indexPath section]];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] %@", alphabet];
    NSArray *wastes = [self.typeOfWaste filteredArrayUsingPredicate:predicate];

    if ([wastes count] > 0) {
        NSString *cellValue = [wastes objectAtIndex:indexPath.row];
        cell.textLabel.font = myFont;
        cell.textLabel.numberOfLines = 2;
        cell.textLabel.text = cellValue;
    }
    return cell;
}

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
    return self.indexWastes;
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    NSIndexPath *indexPath = [self.tableWaste indexPathForSelectedRow];
    WasteDetailViewController *vc = segue.destinationViewController;
    vc.typeOfWaste = [self.typeOfWaste objectAtIndex:indexPath.row];
    vc.typeOfBin = [self.typeOfBin objectAtIndex:indexPath.row];
    vc.urlPic = [self.arrayWastes[indexPath.row]objectForKey:@"imgUrl"];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (IBAction)backToHome:(id)sender {
    [self dismissViewControllerAnimated:YES completion:nil];
}
@end

我希望你能帮助我解决这个问题。谢谢

Answer 1

行按部分编制索引，即每个部分中的第一项具有indexPath.row == 0。因此，为了在展平的vc.typeOfWaste和vc.typeOfBin数组中查找值，您需要在numberOfRowsInSection方法的某些方面执行某些操作，在此方法中筛选展平的数组按字母字符，然后使用indexPath.row获取已过滤数组的项目。

总体而言，这种方法看起来相当混乱，不得不反复过滤您的数据。您的数据结构无法很好地映射到正在解决的问题。我建议使用TLIndexPathTools数据模型TLIndexPathDataModel，因为它专门用于表和集合视图，可以将数据组织成各个部分，并可以按索引路径查找项目。如果你愿意，很乐意引导你完成一个重构。

Answer 2

我前几天也遇到过这个问题...你需要创建一个类设置属性，然后在一个数组中添加该对象，之后你可以在一个属性上排序数组，然后对整个数组进行排序

#import <Foundation/Foundation.h>

@interface HomeFeed : NSObject

@property (nonatomic, copy) UIImage *ItemImage;
@property (nonatomic, copy) NSString *ItemTitle;
@property (nonatomic, copy) NSString *ItemDate;
@property (nonatomic, copy) NSString *ItemDescription;
@property (nonatomic, copy) NSString *ItemHours;
@property (nonatomic, copy) NSString *ItemID;
@property (nonatomic, copy) NSString *itemDetailUrl;
@property (nonatomic, copy) NSString *itemPerson;
@property (nonatomic, copy) NSString *itemThumbUrl;

@property (nonatomic, assign) int ItemDuration;

@end


#import "HomeFeed.h"

@implementation HomeFeed

@synthesize ItemTitle=_ItemTitle, ItemDate=_ItemDate, ItemImage=_ItemImage,ItemID=_ItemID,ItemDuration=_ItemDuration,ItemDescription,ItemHours=_ItemHours,itemDetailUrl,itemPerson,itemThumbUrl;

@end





 NSArray*arr=[responseString JSONValue];
               NSLog(@"Json Dictionary speakersss : %@",arr);
        NSLog(@"Json arr count speaker : %i",arr.count);

        for (int i=0; i<arr.count; i++) {
            NSDictionary *dict=[[ NSDictionary alloc]init];
            dict=[arr objectAtIndex:i];

            HomeFeed *feed = [[HomeFeed alloc] init];


            feed.ItemTitle = [NSString stringWithFormat:@"%@%@%@",[dict objectForKey:@"firstName"],@" ",[dict objectForKey:@"lastName"]];
            feed.ItemDuration = [[NSString stringWithFormat:@"%@", [dict objectForKey:@"count"]] intValue];

            feed.itemDetailUrl=[dict objectForKey:@"detailsUrl"];
            [self.itemsDataArray addObject:feed];
            [itemTitle addObject:feed.ItemTitle];

        }
        HomeFeed *feed = [[HomeFeed alloc] init];

        NSSortDescriptor *sorter = [[NSSortDescriptor alloc] initWithKey:@"ItemTitle" ascending:YES];
        [self.itemsDataArray sortUsingDescriptors:[NSArray arrayWithObject:sorter]];




- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"SpeakersCustomCell"];
    cell.selectionStyle = NO;
    cell.accessoryType = NO;

    HomeFeed *feed = [self.itemsDataArray objectAtIndex:indexPath.row];

    UIImageView *arrow = (UIImageView *)[cell viewWithTag:3];

    arrow.image = [UIImage imageNamed:@"accessory.png"];


    UILabel *lblLeft = (UILabel *)[cell viewWithTag:1];

    UILabel *lblRight = (UILabel *)[cell viewWithTag:2];

    lblLeft.text=feed.ItemTitle;




- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{


    HomeFeed *feed=(HomeFeed*)[self.itemsDataArray objectAtIndex:indexPath.row];
    self.onlinDetail.strUrl=feed.itemDetailUrl;

    NSString *key = @"OrientationStringValue";
    NSDictionary *dictionary = [NSDictionary dictionaryWithObject:feed.itemDetailUrl forKey:key];
    [[NSNotificationCenter defaultCenter] postNotificationName:@"NotifSpeaker1" object:nil userInfo:dictionary];

 }

Answer 3

这是因为您用于将数据传递给WasteDetailViewController的数组（“typeOfWaste，typeOfBin和urlPic”）未排序。已排序的数组称为“wastes”，但它仅在numberOfRowsInSection和cellForRowAtIndexPath方法中可用。你需要向前传递wastes数组中的数据，所以不要一直对wastes数组进行排序，只需在加载后对其进行排序即可。

添加此属性：

@interface TableWasteViewController ()
@property (strong, nonatomic) NSArray *sortedWastes;
@end

现在在viewDidLoad

中

NSString *alphabet = [self.indexWastes objectAtIndex:section];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] %@",alphabet];
self.sortedWastes = [self.typeOfWaste filteredArrayUsingPredicate:predicate];

最后，在prepareForSegue

中

vc.typeOfWaste = [self.sortedWastes objectAtIndex:indexPath.row];

您的问题都源于您正在显示已排序的数组，但您用于向前传递数据的数组是未排序的数组，因此indexPath完全无用。

此外，你的typeOfBin和urlPic也会出错。您需要找到一些方法将所有三个数组链接在一起，这样当您对它们进行排序时，您可以对它们进行排序。上面的方法只会对你的typeOfWaste数组进行排序。

UITableView和字母顺序

3 个答案: