Objective-C困境：cellForRowAtIndexPath崩溃

Question

我希望用户能够在数据库中搜索记录。取回和结果返回完美。我很难设置UItableview来显示结果。该应用程序不断崩溃在cellForRowAtIndexPath。在我心脏病发作之前请有人帮忙。谢谢。

@implementation SearchViewController 
@synthesize mySearchBar; 
@synthesize textToSearchFor; 
@synthesize myGlobalSearchObject; 
@synthesize results; 
@synthesize tableView; 
@synthesize tempString; 

#pragma mark - 
#pragma mark View lifecycle 

- (void)viewDidLoad { 
    [super viewDidLoad]; 
} 

#pragma mark - 
#pragma mark Table View 
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 
    //handle selection; push view 
} 

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{ 
/* if(nullResulSearch == TRUE){ 
     return 1; 
    }else { 
     return[results count]; 
    } 
*/ 
    return[results count]; 
} 

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { 
    return 1; // Test hack to display multiple rows. 
} 

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 

    if(cell == nil){ 
     cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:CellIdentifier] autorelease]; 
    } 

    NSLog(@"TEMPSTRING %@", tempString); 
    cell.textLabel.text = tempString; 

    return cell;  
} 

#pragma mark - 
#pragma mark Memory management 

- (void)didReceiveMemoryWarning { 
    // Releases the view if it doesn't have a superview. 
    [super didReceiveMemoryWarning]; 

} 

- (void)viewDidUnload { 
    self.tableView = nil; 
} 

- (void)dealloc { 
    [results release]; 
    [mySearchBar release]; 
    [textToSearchFor release]; 
    [myGlobalSearchObject release]; 
    [super dealloc]; 
} 

#pragma mark - 
#pragma mark Search Function & Fetch Controller 

- (NSManagedObject *)SearchDatabaseForText:(NSString *)passdTextToSearchFor{ 
    NSManagedObject *searchObj; 
    UndergroundBaseballAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; 

    NSManagedObjectContext *managedObjectContext = appDelegate.managedObjectContext; 
    NSFetchRequest *request = [[NSFetchRequest alloc] init]; 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name == [c]%@", passdTextToSearchFor]; 
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Entry" inManagedObjectContext:managedObjectContext]; 
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:NO]; 
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; 

    [request setSortDescriptors:sortDescriptors]; 
    [request setEntity: entity]; 
    [request setPredicate: predicate]; 

    NSError *error; 

    results = [managedObjectContext executeFetchRequest:request error:&error]; 

    if([results count] == 0){ 
     NSLog(@"No results found"); 
     searchObj = nil; 
     nullResulSearch == TRUE; 
    }else{ 
     if ([[[results objectAtIndex:0] name] caseInsensitiveCompare:passdTextToSearchFor] == 0) { 
      NSLog(@"results %@", [[results objectAtIndex:0] name]); 
      searchObj = [results objectAtIndex:0]; 
      nullResulSearch == FALSE; 
     }else{ 
      NSLog(@"No results found"); 
      searchObj = nil; 
      nullResulSearch == TRUE; 
     }  
    } 

    [tableView reloadData]; 

    [request release]; 
    [sortDescriptors release]; 

    return searchObj; 
} 

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{ 
    textToSearchFor = mySearchBar.text; 
    NSLog(@"textToSearchFor: %@", textToSearchFor); 
    myGlobalSearchObject = [self SearchDatabaseForText:textToSearchFor]; 
    NSLog(@"myGlobalSearchObject: %@", myGlobalSearchObject); 
    tempString = [myGlobalSearchObject valueForKey:@"name"]; 
    NSLog(@"tempString: %@", tempString); 
} 
@end 



*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[UILongPressGestureRecognizer isEqualToString:]: unrecognized selector sent to instance 0x3d46c20' 

Answer 1

这个问题可能与引用计数有关。

在- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar方法，尝试要么

self.tempString = [myGlobalSearchObject valueForKey:@"name"]; 

（假设tempString设置保留）

OR

tempString = [[myGlobalSearchObject valueForKey:@"name"] retain]; 

我会还建议做一些检查零值。即如果[myGlobalSearchObject valueForKey:@"name"] == nil?