cfstring長度的消息發送到解除分配的實例？

我在做自動完成功能的概念，一個文本框，並在這方面，我m到處以下錯誤：「CFString字符串長度的消息發送到釋放實例」cfstring長度的消息發送到解除分配的實例？

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string { 
    if(textField == txtcity) 
    { 

    autocompleteTableView.hidden = NO; 

    NSString *substring = [NSString stringWithString:textField.text]; 
    substring = [substring stringByReplacingCharactersInRange:range withString:string]; 
    [self searchAutocompleteEntriesWithSubstring:substring]; 
    return YES; 
    } 
} 

- (void)searchAutocompleteEntriesWithSubstring:(NSString *)substring { 

    subString2=[NSString stringWithFormat:@"%@",substring]; 


    NSMutableData *data = [[NSMutableData alloc] init]; 
    self.receivedData = data; 
    [data release]; 

    NSURL *jsonUrl =[NSURL URLWithString:[NSString stringWithFormat:@"http://210.90.32.122/services/AutoService.svc/GetCities/?p=%@&k=%@",substring,txtId.text]]; 
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:jsonUrl]; 

    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request 
                    delegate:self]; 
    self.connection = connection; 
    [connection start]; 
} 

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response 

{ 
    [receivedData setLength:0]; 

} 
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 

{ 
    [receivedData appendData:data]; 

} 



- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{ 
    parser = [[NSXMLParser alloc] initWithData:receivedData]; 
    [parser setDelegate:self]; 
    [parser setShouldProcessNamespaces:NO]; 
    [parser setShouldReportNamespacePrefixes:NO]; 
    [parser setShouldResolveExternalEntities:NO]; 
    [parser parse]; 
    [parser release]; 
    NSLog(@"%@",arr2); 
    if([arr2 count]!=0) 
    { 

     self.autocompleteUrls = [[NSMutableArray alloc] init]; 
     if(autocompleteTableView) 
      [autocompleteTableView removeFromSuperview]; 
     autocompleteTableView = [[UITableView alloc] initWithFrame:CGRectMake(88, 428, 200,[arr2 count]*20) style:UITableViewStyleGrouped]; 
     autocompleteTableView.delegate = self; 
     autocompleteTableView.dataSource = self; 
     autocompleteTableView.scrollEnabled = YES; 
     autocompleteTableView.rowHeight=20; 

     [self.view addSubview:autocompleteTableView]; 
       for(int i=0;i<[arr2 count];i++) 
     { 
      NSString *curString = [[arr2 objectAtIndex:i] valueForKey:@"Name"]; 

      NSRange substringRange = [curString rangeOfString:subString2]; //error at this line 

      if (substringRange.location == 0) 
       [autocompleteUrls addObject:curString]; 

     } 
    } 


    [autocompleteTableView reloadData]; 
    txtcity.text=subString2; 
    [txtcity resignFirstResponder]; 

}

我subString2變得null.But我有在decalring中保留它

@property（nonatomic，retain）NSString * subString2;

在哪裏，我要去wrong.Couldn't明白的地方它被釋放..

來源

2012-12-11 Honey

請發佈堆棧跟蹤。 – trojanfoe

CFString length]：發送到釋放實例的消息0x81cb450 – Honey

你不是真正留住它。你不是通過屬性來設置對象變量subString2，這就是原因。試試這個：

self.subString2 = [NSString stringWithFormat:@"%@",substring];

但是通過屬性獲取對象的對象變量並不是很好的做法。有兩種選擇：

[subString2 release]; 
subString2 = [[NSString stringWithFormat:@"%@",substring] copy]; 

OR 

[subString2 release]; 
subString2 = [[NSString stringWithFormat:@"%@",substring] retain];

來源

2012-12-11 10:41:45

哦..這樣一個小小的單詞自制了很多不同。感謝Paul – Honey

cfstring長度的消息發送到解除分配的實例？

回答

相關問題