在自定义单元格（xib）中滚动时，UITextField 中的文本消失

Posted 2023-03-04

【中文标题】在自定义单元格（xib）中滚动时，UITextField 中的文本消失

【英文标题】：Text in UITextField disappear when scrolling in custom cell (xib)

【发布时间】：2013-05-02 06:24:55

【问题描述】：

我已经阅读了很多关于我的问题的信息，但我仍然无法指出确切的问题。 如果代码在堆栈中，我已经尝试了一些，但我不断收到错误。 下面的代码有效，但滚动时文本消失。

有什么想法吗？

GetQuestionsCustomCell.h：

@interface GetQuestionsCustomCell : UITableViewCell <UITextFieldDelegate>

@property (strong, nonatomic) IBOutlet UILabel *labelQuestion;
@property (strong, nonatomic) IBOutlet UITextField *textFieldAnswer;
@property (strong, nonatomic) IBOutlet UILabel *labelQuestionNumber;
- (IBAction)KeyDown:(id)sender;

@end

GetQuestionsCustomCell.m：

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier

    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) 
        // Initialization code
        NSArray *nibArray = [[NSBundle mainBundle] loadNibNamed:@"GetQuestionsCustomCell" owner:self options:nil];
        self = [nibArray objectAtIndex:0];
        self.textFieldAnswer.delegate = self;
    
    return self;

SecurityQuestions.m：

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

    static NSString *CellIdentifier = @"Cell";

    GetQuestionsCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) 
        cell = [[GetQuestionsCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;
    


    NSInteger nextIndexPathRow = indexPath.row;
    nextIndexPathRow++;
    cell.labelQuestion.text = [arrayOfQuestions objectAtIndex:indexPath.row];
    cell.labelQuestionNumber.text = [NSString stringWithFormat:@".%d", nextIndexPathRow];

    switch (indexPath.row) 
        case 0:
            tfA1 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 1:
            tfA2 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 2:
            tfA3 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 3:
            tfA4 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 4:
            tfA5 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 5:
            tfA6 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 6:
            tfA7 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 7:
            tfA8 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 8:
            tfA9 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 9:
            tfA10 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 10:
            tfA11 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 11:
            tfA12 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
    

    return cell;

【问题讨论】：

问题在于单元格可重用.. 当自定义单元格中有 UITextField 时，您只需要知道如何重用单元格.. 这可能对您有帮助 ***.com/a/4568460/1059705 和 ***.com/q/4045658/1059705

我能问你一件事，你想从每个文本字段中获取用户输入吗？

从文本字段中获取每个数据并保存以备后用。

【参考方案1】：

确切的问题是您既没有保存文本字段的值，也没有将它们设置在cellForRowAtIndexPath

当用户在文本字段中输入内容时，您需要将值跟踪到某处，可能在您的 ViewController 中按问题编号索引的数组中。一种方法是跟踪cellForRowAtIndexPath 中的单元格：

cell.textFieldAnswer.tag = indexPath.row;
cell.textFieldAnswer.delegate = self;

然后你需要在你的视图控制器中实现- (void)textFieldDidEndEditing:(UITextField *)textField。将那里的值另存为：

[self.answers replaceObjectAtIndex:textField.tag withObject: textField.text];

然后你需要在你的cellForRowAtIndexPath 中再次将值设置为[cell.textFieldAnswer setText:[self.answers objectAtIndex:indexPath.row]]

原因是，如果你有 1000 个问题，ios 不会创建 1000 个单元格。它将重用单元格。您需要进一步了解 tableView：TableView Programming Guide

希望这会有所帮助。

【讨论】：

处理..的确切方法:)

好的，谢谢您的回答。我想在编辑完成时从文本字段中获取文本，但使用 - (BOOL)textFieldShouldReturn:(UITextField *)textField 和 - (void)textFieldDidEndEditing:(UITextField *)textField 对我来说有点问题，因为我需要设置委托给文本字段，但文本字段在自定义类中，知道我如何处理它吗？

非常感谢！哦，cell.textFieldAnswer = indexPath.row;给我错误“...的隐式转换”

你的意思可能是：cell.textFieldAnswer.tag = indexPath.row;

第一次不工作。它崩溃了。第一次数组呢。

【参考方案2】：

更改 CellForRowIndexPath...

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

    static NSString *CellIdentifier = @"Cell";

    GetQuestionsCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) 
        cell = [[GetQuestionsCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;

    switch (indexPath.row) 
        case 0:
            tfA1 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 1:
            tfA2 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 2:
            tfA3 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 3:
            tfA4 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 4:
            tfA5 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 5:
            tfA6 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 6:
            tfA7 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 7:
            tfA8 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 8:
            tfA9 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 9:
            tfA10 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 10:
            tfA11 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
        case 11:
            tfA12 = (UITextField*)[cell.contentView viewWithTag:nextIndexPathRow];
            break;
    


    NSInteger nextIndexPathRow = indexPath.row;
    nextIndexPathRow++;
    cell.labelQuestion.text = [arrayOfQuestions objectAtIndex:indexPath.row];
    cell.labelQuestionNumber.text = [NSString stringWithFormat:@".%d", nextIndexPathRow];

[tfA1 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA2 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA3 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA4 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA5 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA6 setText:[self.answers objectAtIndex:indexPath.row]];
[tfA7 setText:[self.answers objectAtIndex:indexPath.row]];
  
   return cell;

【参考方案3】：

这是一个使用tableView delegate method 的简单解决方法，并在此方法中保存您的UITextview.text 值，

- (void)tableView:(UITableView *)tableView didEndDisplayingCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath


//Save the textField values