iOS：重置UIPickerView EXC_BAD_ACCESS错误

Question

I am using a PickerView to choose values and I want to reset it, (so it doesn't show the previous selection) after pressing a button.

The problem is I am always getting one of two errors, it changes from run to run with no apparent pattern.

Does anyone know what might cause the errors, respectively how to solve the problem?

Code:

NSString * chosen;
NSString * elemString;
NSMutableArray *secondTableArray ;
NSInteger p = 0;
@implementation LagerViewController
@synthesize requestObject;
@synthesize choosenDocKind;
@synthesize pickerView1;

#pragma mark - View lifecycle
- (void)viewDidLoad
{
    [super viewDidLoad];
    secondTableArray = [[NSMutableArray alloc] init];
    secondTableView.scrollEnabled = YES;
    secondTableView.bounces = YES;
    elemString = @"";
    choosenDocKind = [[NSString alloc] initWithString:@""];
    [pickerView removeFromSuperview]; 
}

- (void)tableView:(UITableView *)theTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(pickerViewItems != nil)
    {
        [pickerViewItems release];
        pickerViewItems = nil;
    } 
    if((indexPath.section == 1)&&(indexPath.row == 0))
    {
        NSString * temp = [[NSString stringWithFormat:@"%@",elemString] copy];
        NSString * tableString;
        if([temp length] == 0) {
             [secondTableArray removeAllObjects];
             [secondTableView reloadData];  
             elemString = [[NSString stringWithFormat:@"ARTIKEL: %@ %@ %@", matchcode, quantity, choosenDocKind] copy];
             tableString = [[NSString stringWithFormat:@"%@ %@ %@", matchcode, quantity, choosenDocKind] copy];

             // THESE 2 ROWS BELOW CAUSE THE ERRORS
             [pickerView reloadAllComponents];
             [pickerView selectRow:0 inComponent:0 animated:YES];
        }
    }
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
    [theTableView deselectRowAtIndexPath:indexPath animated:YES];
}

#pragma mark - button events
- (IBAction)btnSubmitPVSelection:(id)sender
{
    if([choosenPrompt isEqualToString:NSLocalizedString(@"DOCUMENT_REQUEST_LAGER_UM", nil)])
    {
        if(choosenDocKind != nil)
        {
            chosen = choosenDocKind;
            [choosenDocKind release];
            choosenDocKind = nil;
        }
        choosenDocKind = [[[NSString alloc] initWithString:[pickerViewItems objectAtIndex:[pickerView selectedRowInComponent:0]]] retain];
    }
    [tvArchDocParam reloadData];
    if(choosenPrompt != nil)
    {
        [self.presentedViewController dismissViewControllerAnimated:NO completion:nil];
        [choosenPrompt release];
        choosenPrompt = nil;
    }
    [pickerView reloadAllComponents];
    [pickerView selectRow:0 inComponent:0 animated:YES];
}

.h

@interface ... {
    DocRequest *requestObject;
    NSArray *pickerViewItems;
    NSString *choosenPrompt;
    UITextView *matchtext;
    IBOutlet UITableView *tvArchDocParam;
    UIAlertController *actionSheet;
    UITableView *theTableView;
    IBOutlet UITableView *secondTableView;
}   
@property (nonatomic, retain)DocRequest* requestObject;
@property (nonatomic, retain)UIPickerView *pickerView1;
-(UITableViewCell*)getSelectorCell:(NSString*)CellIdentifier;
-(UITableViewCell*)getTextFieldCell:(NSString*)CellIdentifier;
-(void)showPickerView;

Errors:

1. Thread 1: EXC_BAD_ACCESS
2. Terminating app due to uncaught exception 'NSInvalidArgumentException', reason NSDictionaryM reloadAllComponents

Answer 1

First and most important — stop using manual memory management.

Second about crashes, looks like both crashes related and caused by the same issue (due to code you gave us, it's impossible to guess what exactly make app crash), obviously your pickerView was released somewhere before [pickerView reloadAllComponents]; was called.

It may be caused because of [pickerView removeFromSuperview]; in viewDidLoad for example if you pickerView is assign or something like that.