在tableView中搜索单元格问题

Question

I am using xcode 5 and want to search a tableView data. I used "Search Bar & Search Display Controller" for "searching", "CustomCell" for "tableCell" and all the data are parsing from a remote server by NSXMLParsing. All data are showing with their corresponding image without any problem but some how my search option doesn't work properly. I do the same code for a single array searsing and it was working. But here it isn't. At the time of searching it is crashed. Here is my code:

-(void)loadData
{
    countryParser = [[CountryParser alloc] loadXMLByURL:@"http://www.avowstudio.com/iOS/PartProject/iOS7/XMLParsingWithCustomeCell/XMLFiles/XMLParsingWithCustomCell.xml"];

    countryArray = [countryParser countryArray];

    displayItems = [[NSMutableArray alloc] initWithArray:countryArray];

    [self.countryTableView reloadData];
    [activityIndicator stopAnimating];
    [self loadArray];
}



-(void) loadArray
{
    CountryInfo *currentCountryOne = [[CountryInfo alloc] init];
    totalArray = [[NSMutableArray alloc] init];

    for (int i=0; i < [countryArray count]; i++)
    {
        currentCountryOne = [countryArray objectAtIndex:i];
        [totalArray addObject:currentCountryOne.countryName];
    }
}


-(void) searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    if ([searchText length] == 0)
    {
        [displayItems removeAllObjects];
        [displayItems addObjectsFromArray:countryArray];
    }
    else
    {
        [displayItems removeAllObjects];
        displayItems = [[NSMutableArray alloc] init];

        for (NSString *string in totalArray)
        {
            NSRange stringRang = [string rangeOfString:searchText options:NSCaseInsensitiveSearch];
            if (stringRang.location != NSNotFound)
            {
                [displayItems addObject:string];
            }
        }
    }
    [self.countryTableView reloadData];
}



- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [displayItems count];
}

// This method is kept the "tableRow height" after "done searching"
- (void)searchDisplayController:(UISearchDisplayController *)controller didLoadSearchResultsTableView:(UITableView *)tableView
{
    tableView.rowHeight = 100;
}

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

    CountryCustomCell *Cell = [self.countryTableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (!Cell)
    {
        Cell = [[CountryCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    currentCountry = [displayItems objectAtIndex:indexPath.row];

    Cell.ContinentLabel.text = currentCountry.continent;
    Cell.CountryNameLabel.text = currentCountry.countryName;
    Cell.CapitalLabel.text = currentCountry.capital;

    imageQueueCountryFlag = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
dispatch_async(imageQueueCountryFlag, ^
    {
        UIImage *imageCountryFlag = [UIImage imageWithData:[NSData dataWithContentsOfURL: [NSURL URLWithString:[currentCountry countryFlag]]]];
    dispatch_async(dispatch_get_main_queue(), ^
        {
            Cell.CountryFlagImageView.image = imageCountryFlag;
            [Cell setNeedsLayout];
        });
    });

return Cell;

}

I don't want to use two Array in "numberOfRowsInSection" & "cellForRowAtIndexPath" with flag or some thing like that, to avoid more coding. If any one familiar with it please share that here. A lot of thanks in advanced.

Answer 1

Instead of adding string to displayItems add the objects containing information about country.

[displayItems addObject:string];

Here you are adding only the countryName to displayItems but while calling cellForRowAtIndexPath: you are asking for its continent,country name and capital which is not present in the array (displayItems) when you reload table after searching.

Answer 2

I think you are added objects of CountryInfo in the [countryParser countryArray] . In your loadArray method, you just initializing a blank object currentCountryOne and each time the for loop executes, trying to add a blank object's property into totalArray. Please make changes as below:

-(void) loadArray
{
    totalArray = countryArray;
}


-(void) searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    if ([searchText length] == 0)
    {
        [displayItems removeAllObjects];
        [displayItems addObjectsFromArray:countryArray];
    }
    else
    {
        [displayItems removeAllObjects];
        displayItems = [[NSMutableArray alloc] init];

        for (CountryInfo *country in totalArray)
        {
            NSRange stringRang = [country.countryName rangeOfString:searchText options:NSCaseInsensitiveSearch];
            if (stringRang.location != NSNotFound)
            {
                [displayItems addObject:country];
            }
        }
    }
    [self.countryTableView reloadData];
}

Answer 3

Exactly which error did you get when it crashed?

It seems to be that when you add an object to your displayItems array. You just add the string object, not the country object.

Your currentCountry is not a country object just the string .

So, in your code enter:

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

When you try to parse, it cannot reach:

continent

countryName

capital

Be careful when you search a detailed object.

Answer 4

当您搜索时，添加字符串以显示不是CountryInfo对象的项目，因此当再次调用cellforrow atindexpath时，它必须崩溃