在表格單元格中獲取/設置UITextField值

Question

對於我當前的項目，我需要一個表格，其中包含每個單元格中的文本字段，單元格和文本字段的數量必須是動態的，取決於MutuableArray中的數據數量。我有單元格中的文本框工作，但我無法獲取/設置文本框的值。我想知道你們是否可以幫助我，或者至少糾正我做錯了什麼？非常感謝你的提前。請參閱下面的代碼片段：

// Adds textfield into cell 

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { 

    static NSString *CellIdentifier = @"Cell"; 
    UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 

    if (cell == nil) { 
     NSUInteger row = indexPath.row; 
     X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:row]; 
     cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; 

     BOOL bShowSelection = ([curIndex.HasVasteWaarden isEqualToString:@"false"]); 

     if (bShowSelection) { 
      bShowSelection = !([curIndex.DataType isEqualToString:@"Datum"]); 
     } 

     if ([indexPath section] == 0) { 
      if (bShowSelection) { 
       cell.accessoryType = UITableViewCellAccessoryNone; 
      } else { 
       cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton; 
      } 

      UITextField *editField = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)]; 
      editField.adjustsFontSizeToFitWidth = YES; 
      editField.textColor = [UIColor blackColor]; 
      editField.placeholder = curIndex.Naam; 
      editField.keyboardType = UIKeyboardTypeDefault; 
      editField.returnKeyType = UIReturnKeyNext; 
      editField.backgroundColor = [UIColor whiteColor]; 
      editField.autocorrectionType = UITextAutocorrectionTypeNo; // no auto correction support 
      editField.autocapitalizationType = UITextAutocapitalizationTypeNone; // no auto capitalization support 
      editField.textAlignment = UITextAlignmentLeft; 
      editField.clearButtonMode = UITextFieldViewModeNever; // no clear 'x' button to the right 
      editField.tag = [curIndex.UID intValue]; 

      [editField setEnabled: YES]; 
      [cell addSubview:editField]; 

      [editField release]; 
     } 
    } 

    return cell; 
} 

在某些情況下，我使用popovercontroller來顯示數據列表。用戶可以選擇彈出窗口的值。該代碼被執行時，有選擇的值：

- (void)selectedValue:(NSString *) value { 

    //---update value of the text field --- 
    //The first attempt it doesn't put the text to text field 

    //static NSString *CellIdentifier = @"Cell"; 
    //UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 
    // 
    //if (cell == nil) { 
    // cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; 
    //} 

    // second attempt it crashes 
    X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:curRow.row]; 
    int index = [curIndex.UID intValue]; 
    UITextField *textField = (UITextField *) [curCell viewWithTag: index]; 
    if (textField) { 
      [textField setText:value]; 
    } 

    [textField release]; 

    [self.popOverController dismissPopoverAnimated:YES]; 
} 

當選定單元格，我確保了該小區後保存使用。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 

    X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:indexPath.row]; 

    if (!curIndex) { 
     return; 
    } 

    curRow = indexPath; // saves the selected row 

    if ([curIndex.VasteWaarden count] > 0) { 
     UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath]; 
     curCell = cell; // saves the selected cell 

     CGRect frame = [cell.superview convertRect:cell.frame toView:self.view]; 

     self.detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];   
     detailViewController.delegate = self; 
     self.popOverController = [[[UIPopoverController alloc] initWithContentViewController:detailViewController] autorelease];    

     X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:indexPath.row]; 
     self.detailViewController.Values = curIndex.VasteWaarden; 

     [self.popOverController presentPopoverFromRect:frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; 
    } 
} 

再次感謝提前。

乾杯， Inoel

Answer 1

在第二代碼片段你釋放文本字段。你不應該這樣做，因爲你沒有保留它。由於viewWithTag:簡單獲取對文本字段的引用，因此它不保留textField。因此，您將它保留更多次，因此retainCount達到0，並且文本字段是從內存中分配的。然後當您第二次嘗試時，內存中沒有文本字段。

只需卸下：

[textField release]; 

從第二代碼片段。如果你不明白爲什麼，那麼閱讀一些關於內存管理的文章（只是谷歌它）。完全理解它需要一些時間，至少我知道它花了我一段時間:)