从单元格的文本字段返回空值

Question

我创建了一个带有文本字段的自定义单元格，但无法检索其值。
在我的 tableView 中，有 3 个自定义单元格以及其他默认单元格。
当我尝试这个时：

NSString *string = customCell.textField.text;

我总是得到一个空值...
这是我的代码：

TextFieldCell.m

#import "TextFieldCell.h"

@implementation TextFieldCell

@synthesize label;
@synthesize textField;

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self)
    {
        label = [[UILabel alloc] initWithFrame:CGRectZero];
        label.backgroundColor = [UIColor clearColor];
        label.textAlignment = UITextAlignmentRight;
        label.textColor = [UIColor blackColor];
        label.font = [UIFont boldSystemFontOfSize:16.0];
        label.adjustsFontSizeToFitWidth = YES;
        label.baselineAdjustment = UIBaselineAdjustmentNone;
        label.numberOfLines = 20;
        [self.contentView addSubview:label];

        textField = [[UITextField alloc] initWithFrame:CGRectZero];
        textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
        textField.backgroundColor = [UIColor clearColor];
        textField.font = [UIFont boldSystemFontOfSize:16.0];
        textField.delegate = self;
        textField.returnKeyType = UIReturnKeyDone;
        [self.contentView addSubview:textField];
    }

    return self;
}

-(void)layoutSubviews
{
    [super layoutSubviews];

    CGRect r = CGRectInset(self.contentView.bounds, 8, 8);
    CGRect r1 = CGRectInset(self.contentView.bounds, 8, 8);

    if (label.text != nil)
    {
        r.size = CGSizeMake(12, 27);
        label.frame = r;

        r1.origin.x += self.label.frame.size.width + 6;
        r1.size.width -= self.label.frame.size.width + 6;
        textField.frame = r1;
    }
    else
    {
        textField.frame = r;
    }
}

-(BOOL)textFieldShouldReturn:(UITextField *)aTextField
{
    [textField resignFirstResponder];
    return NO;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
    [super setSelected:selected animated:animated];
}

@end

表视图数据源

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.section == 0)
    {
        if (indexPath.row == 0)
        {
            return [self textFieldCellForTableView:tableView atIndexPath:indexPath];
        }
        else if (indexPath.row == 1)
        {
            return [self textFieldCellForTableView:tableView atIndexPath:indexPath];
        }
        else
        {
            return [self defaultCellForTableView:tableView atIndexPath:indexPath];
        }
    }
    else if (indexPath.section == 1)
    {
        if (indexPath.row == 0)
        {
            return [self textFieldCellForTableView:tableView atIndexPath:indexPath];
        }
        else
        {
            return [self defaultCellForTableView:tableView atIndexPath:indexPath];
        }
    }
    else if (indexPath.section == 2)
    {
        return [self defaultCellForTableView:tableView atIndexPath:indexPath];
    }
    else
    {
        return [self chooseFotoCellForTableView:tableView atIndexPath:indexPath];
    }
}

-(TextFieldCell *)textFieldCellForTableView:(UITableView *)tableView atIndexPath:(NSIndexPath *)indexPath
{
    static NSString *TextFieldCellIdentifier = @"TextFieldCellIdentifier";

    TextFieldCell *cell = [tableView dequeueReusableCellWithIdentifier:TextFieldCellIdentifier];
    if (cell == nil)
    {
        cell = [[[TextFieldCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:TextFieldCellIdentifier] autorelease];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;
    }

    if (indexPath.section == 0)
    {
        if (indexPath.row == 0)
        {
            cell.label.text = nil;
            cell.textField.placeholder = NSLocalizedString(@"Nome", @"");
        }
        else
        {
            cell.label.text = [[NSLocale currentLocale] objectForKey:NSLocaleCurrencySymbol];
            cell.textField.placeholder = NSLocalizedString(@"Costo", @"");
        }
    }
    else
    {
        cell.label.text = nil;
        cell.textField.placeholder = NSLocalizedString(@"URL", @"");
    }

    return cell;
}

代码检索 TextField 值

TextFieldCell *nomeCell = (TextFieldCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
TextFieldCell *costoCell = (TextFieldCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:0]];
TextFieldCell *linkCell = (TextFieldCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:1]];

NSLog(@"nomeCell textField = %@", nomeCell.textField.text);
NSLog(@"costoCell textField = %@", costoCell.textField.text);
NSLog(@"linkCell textField = %@", linkCell.textField.text);

我尝试记录 nomeCell、costoCell 和 linkCell，它们已正确分配和初始化，并且我在这里没有使用 ARC...
谁能帮我吗？
太感谢了！

Answer 1

我假设当您尝试检索值时，您实际上已经在文本字段中输入了一些文本，并且您正在检索值以更新数据模型，而不是依赖表视图/单元格来存储数据？

不要通过调用表视图控制器的 tableView:cellForRowAtIndexPath: 来获取当前单元格。仅当表视图需要新单元格时才应调用此方法。

直接在表格视图上调用 cellForRowAtIndexPath: 方法。而不是这样：

TextFieldCell *nomeCell = (TextFieldCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];

这样做：

TextFieldCell *nomeCell = (TextFieldCell *)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];

Answer 2

您正在将文本分配给 placeholder 属性，并且正在记录 textField.text。

Answer 3

textField = [[UITextField alloc] initWithFrame:CGRectZero];
        textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
        textField.backgroundColor = [UIColor clearColor];
        textField.font = [UIFont boldSystemFontOfSize:16.0];
        textField.delegate = self;

        //added
        textField.tag = 101;

        textField.returnKeyType = UIReturnKeyDone;
        [self.contentView addSubview:textField];

检索文本字段值的代码：

//fetch cell for which you want to get textfield then,
TextFieldCell *nomeCell = (TextFieldCell *)[cell.contentView viewWithTag:101];