Question

我正在尝试为我的uitableview设置索引和部分，我已经设法做了..但是现在我试图将我的NSDictionary值传递给我的uitableviewcell我的应用程序在我尝试访问NSDictionary时崩溃了在我从中传递值的方法之外。

我在想，也许我没有正确地传递这些值或者其他的东西，但我根本无法弄清楚为什么会这样......

继承我的代码......

·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;

//....

的.m

//...
//This is where I try to access the 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];
}

。在上面的最后一个方法中用NSLog检查字典的输出

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
    );
}

我已经调试了两个点（我在方法中设置了NSdictionary）和（我在cellforrowatindexpath中访问NSDictionary）并在我尝试使用它之前进行了默认设置。

任何帮助将不胜感激..

Answer 1

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

从属性声明中删除 IBOutlet。它仅适用于Interface Builder控件。

同样纠正dictonary分配 - self.arraysByLetter = [NSMutableDictionary dictionary];

Answer 2

分配的NSMutableDictionary为autoreleased，因此当在其他方法中调用NSAutoreleasePool时，NSMutableDictionary已被耗尽，released已self.arraysByLetter = [NSMutableDictionary dictionary]; }}。如果你想使用属性保留对象，你必须这样做：

self

retain将使用声明为autoreleased的setter设置字典，因此当您稍后尝试使用它时它将可用。

请注意，不以new或alloc或contains副本开头的任何方法都必须返回{{1}}对象，这是您的情况。

无法访问NSMutableDictionary外部方法，其中传递值

2 个答案: