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Cannot access NSMutableDictionary outside method where values are passed into it

开发者 https://www.devze.com 2023-04-07 00:59 出处:网络
I am trying to set up Index and sections for my uitableview, which I have managed to do.. However now that I am trying to pass my NSDictionary values over to my uitableviewcell my app is crashing when

I am trying to set up Index and sections for my uitableview, which I have managed to do.. However now that I am trying to pass my NSDictionary values over to my uitableviewcell my app is crashing when I try to access the NSDictionary outside of the method that I passed the values to it from.

I am thinking that maybe I am not passing the values in correctly or something along the line of that, but I simply cannot figure out why its going this...

Heres my code...

.h

@interface VehicleResultViewController : UITableViewController <NSXMLParserDelegate> {

//......

    //Indexed tableview stuff
    NSArray *sortedArray;
    NSMutableDictionary *arraysByLetter;
    NSMutableArray *sectionLetters;

}


//.....

//Indexed tableview stuff
@property (nonatomic, retain) IBOutlet NSArray *sortedArray;
@property (nonatomic, retain) IBOutlet NSMutableDictionary *arraysByLetter; 
@property (nonatomic, retain) IBOutlet NSMutableArray *sectionLetters;

//....

.m

//...
//This is where I try to access t开发者_JAVA百科he NSDictionary to pass it to my uitableviewcells
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    } 

    cell.accessoryType = UITableViewCellAccessoryNone; //make sure their are no tickes in the tableview 
    cell.selectionStyle = UITableViewCellSelectionStyleNone; // no blue selection

    // Configure the cell...

    NSString *value = [self.arraysByLetter objectForKey:[[self.arraysByLetter allKeys] objectAtIndex:indexPath.row]];
    cell.textLabel.text = key;
    NSLog(@"%@",arraysByLetter);

    return cell;
}

//This is where I set NSDictionary
//method to sort array and split for use with uitableview Index
- (IBAction)startSortingTheArray:(NSMutableArray *)arrayData
{
    //Sort incoming array alphabetically
    sortedArray = [arrayData sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
    //NSLog(@"%@",sortedArray);

    // Dictionary will hold our sub-arrays
    arraysByLetter = [NSMutableDictionary dictionary];
    sectionLetters = [[NSMutableArray alloc] init];
    // Iterate over all the values in our sorted array
    for (NSString *value in sortedArray) {

        // Get the first letter and its associated array from the dictionary.
        // If the dictionary does not exist create one and associate it with the letter.
        NSString *firstLetter = [value substringWithRange:NSMakeRange(0, 1)];
        NSMutableArray *arrayForLetter = [arraysByLetter objectForKey:firstLetter];
        if (arrayForLetter == nil) {
            arrayForLetter = [NSMutableArray array];
            [arraysByLetter setObject:arrayForLetter forKey:firstLetter];
            [sectionLetters addObject:firstLetter]; // This will be used to set index and section titles
        }

        // Add the value to the array for this letter
        [arrayForLetter addObject:value];
    }
    // arraysByLetter will contain the result you expect
    NSLog(@"Dictionary: %@", arraysByLetter); //This prints what is currently in the NSDictionary

    //Reloads data in table
    [self.tableView reloadData];
}

.output of checking the Dictionary with NSLog in the last method above

Dictionary: {
    H =     (
        Honda,
        Honda,
        Honda,
        Honda,
        Honda,
        Honda,
        Honda
    );
    M =     (
        Mazda,
        Mazda,
        Mitsubishi,
        Mitsubishi,
        Mitsubishi,
        Mitsubishi,
        Mitsubishi,
        Mitsubishi
    );
    N =     (
        Nissan,
        Nissan,
        Nissan,
        Nissan,
        Nissan,
        Nissan,
        Nissan
    );
    T =     (
        Toyota,
        Toyota,
        Toyota
    );
}

I have debugged the two points (where i set the NSdictionary in the method) and (where I access the NSDictionary in cellforrowatindexpath) and it is defiantly set before I even try to use it.

Any help would be greatly appreciated..


//Indexed tableview stuff
@property (nonatomic, retain) NSArray *sortedArray;
@property (nonatomic, retain) NSMutableDictionary *arraysByLetter; 
@property (nonatomic, retain) NSMutableArray *sectionLetters;

REMOVE IBOutlet from properties declarations. It's only for Interface Builder controls.

Also correct dictonary allocation - self.arraysByLetter = [NSMutableDictionary dictionary];


The NSMutableDictionary that is allocated is autoreleased, therefore when it is called in the other method the NSAutoreleasePool has been drained, and the NSMutableDictionary has been released. If you want to retain the object using the property you have to do it like this:

self.arraysByLetter = [NSMutableDictionary dictionary];

self will set the dictionary using the setter which is declared as retain, so it will be available when you try to use it later on.

As a note any method that does not start with new or alloc or contains copy must return an autoreleased object, which is your case.

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