iOS UItableView 通过索引路径从数组中删除对象

Question

我有按 A-Z 部分排序的自定义通讯录。我正在尝试将所选联系人添加到数组中

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

NSMutableDictionary *contactInfo = [NSMutableDictionary new];

Cell *cell = (Cell *)[self.contTableView cellForRowAtIndexPath:indexPath];

//NSLog(@"CELL %@", cell.contact.fullname);

if (!cell.contact.contactChecked) {

    cell.contactImage.image = [UIImage imageNamed:@"cell_blue_circle.png"];
    cell.contact.contactChecked = YES;
    //NSLog(@"DID SELECT %@", cell.contact.fullname);
    NSLog(@"index checked row %d section %d", indexPath.row, indexPath.section);
    [contactInfo setValue:cell.contact.fullname forKey:@"name"];
    [contactInfo setValue:cell.contact.numbers.firstObject forKey:@"phone"];

    [self.seletedPeople insertObject:contactInfo atIndex:indexPath.row];

} else {
     NSLog(@"index unchecked row %d section %d", indexPath.row, indexPath.section);
    cell.contactImage.image = [UIImage imageNamed:@"cell_gray_circle.png"];
    cell.contact.contactChecked = NO;
    [self.seletedPeople removeObjectAtIndex:indexPath.row];
}

NSLog(@"DICT SELECTED %@", self.seletedPeople);

}

发生了什么，在某些单元应用程序中因错误而崩溃

* 由于未捕获的异常 'NSRangeException' 导致应用程序终止，原因：'* -[__NSArrayM insertObject:atIndex:]: index 1 beyond 空数组的边界' *** 第一次抛出调用堆栈：（0x29c02fef 0x38150c8b 0x29b1cf8f 0xf7fe9 0x2d36e56b 0x2d41d43b 0x2d2d2a91 0x2d24d38f 0x29bc8fed 0x29bc66ab 0x29bc6ab3 0x29b13201 0x29b13013 0x313f2201 0x2d2b7a59 0x10c075 0x386dcaaf) libc++abi.dylib: 以未捕获的异常终止 输入 NSException

更新：

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

static NSString *cellID = @"Cell";
Cell *cell = [tableView dequeueReusableCellWithIdentifier:cellID forIndexPath:indexPath];

if (searchResults) {

    //NSLog(@"CELL %@", cell.contact.fullname);
    contact = [searchResults objectAtIndex:indexPath.row];
    cell.contact = contact;
    cell.firstNameLabel.text = contact.fullname;
    cell.avatar.image = contact.image;
    cell.avatar.layer.borderColor = [UIColor grayColor].CGColor;
    cell.avatar.layer.borderWidth = 0.5;
    cell.avatar.layer.cornerRadius = 25.0;
    cell.avatar.layer.masksToBounds = YES;
    cell.number.text = contact.numbers.firstObject;

} else {

    NSString *sectionTitle = [[[namesDictionary allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)]
                              objectAtIndex:indexPath.section];
    NSArray *sectionContacts = [namesDictionary objectForKey:sectionTitle];
    contact = [self getContactFromArray:[sectionContacts objectAtIndex:indexPath.row]];

    cell.firstNameLabel.text = [sectionContacts objectAtIndex:indexPath.row];

    cell.avatar.image = contact.image;
    cell.avatar.layer.borderColor = [UIColor grayColor].CGColor;
    cell.avatar.layer.borderWidth = 0.5;
    cell.avatar.layer.cornerRadius = 25.0;
    cell.avatar.layer.masksToBounds = YES;
    cell.number.text = contact.numbers.firstObject;

    cell.contact = contact;

    cell.tag = indexPath.row;
}

if (contact.contactChecked) {
    cell.contactImage.image = [UIImage imageNamed:@"cell_blue_circle.png"];
} else {
    cell.contactImage.image = [UIImage imageNamed:@"cell_gray_circle.png"];

}


return cell;

}

Answer 1

我在这种情况下使用的方式。我创建一个模型类并用模型加载表格视图。现在，当我选择一个单元格或取消选择一个单元格时。我只是将该模型添加到另一个数组中。之后，当我取消选择已选择的单元格时，我可以从 indexpath.row 中获取相同的模型，然后我可以使用 NSArray 方法在该选定数组中获取该模型并将其从那里删除。要解决您的问题，您可以在选择过程中使用 indexPath.row 作为字典中的另一个键。之后，当您取消选择单元格时，使用谓词从用于存储所选单元格的数组中获取添加的字典。找到后将其从数组中删除。

Answer 2

这里的问题是模型与视图对象的耦合，您不应该从视图本身（在您的情况下为Cell）查询某个属性，但是检查的联系人应该从数据源对象（您用来提供 cellForRowAtIndexPath: 的对象，应该从中查询它。

否则，由于耦合可能导致代码错误且不稳定，因为它可能指向一个空对象

Answer 3

问题出在这里：

[self.seletedPeople insertObject:contactInfo atIndex:indexPath.row];

如果selectedPeople 为空并且用户单击第2 行，那么它将尝试将contactInfo 插入“超出空数组的范围”的第2 行。只需使用 addObject: 代替。您还需要更改从该数组中删除项目的方式（最好使用字典代替）。

Answer 4

解决方案是将联系人记录 ID 添加到我的字典中，并使用谓词此联系人 ID 进行搜索。然后删除它。感谢@jassi

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



    NSMutableDictionary *contactInfo = [NSMutableDictionary new];

    Cell *cell = (Cell *)[tableView cellForRowAtIndexPath:indexPath];

    if (!cell.contact.contactChecked) {

        cell.contactImage.image = [UIImage imageNamed:@"cell_blue_circle.png"];
        cell.contact.contactChecked = YES;
        //NSLog(@"DID SELECT %@", cell.contact.fullname);
        NSLog(@"index checked %@ ", [indexPath description]);
        [contactInfo setValue:cell.contact.fullname forKey:@"name"];
        [contactInfo setValue:cell.contact.numbers.firstObject forKey:@"phone"];
        [contactInfo setValue:@(cell.contact.contactId) forKey:@"contactId"];


        [self.seletedPeople addObject:contactInfo];

    } else {
         NSLog(@"index unchecked %@", [indexPath description]);
        cell.contactImage.image = [UIImage imageNamed:@"cell_gray_circle.png"];
        cell.contact.contactChecked = NO;
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"contactId == %d", cell.contact.contactId];
        NSArray *resultTemp = [self.seletedPeople filteredArrayUsingPredicate:predicate];

    if(resultTemp.count>0)
        [self.seletedPeople removeObject:resultTemp[0]];


    }

    NSLog(@"DICT SELECTED %@", self.seletedPeople);
}

Answer 5

正如 user2320861 所说，问题出在您使用 insertObject 的那一行。我会做以下事情：

1. 使用以下代码将 self.selectedPeople 更改为 NSMutableDictionary：

   //in your @interface
   @property (nonatomic, strong) NSMutableDictionary *selectedPeople;
   

2. 将didSelectCellAtIndexPath中的代码改为：

   //Since phone numbers are unique.
   self.selectedPeople[cell.contact.numbers.firstObject] = contactInfo;
   

3. 稍后使用此代码检索所有联系人：

   for(id key in self.selectedPeople) {
       NSDictionary contactInfo = [self.selectedPeople objectForKey:key];
       //Do something with that contactInfo
   }