UITableViewCell 内的 UITextField

Question

我目前在两个相应的 UITableViewCells 中有两个 UITextFields。

它看起来是这样的：

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.

//adding all the UITextField's to the UITableViewCell is a pain in the ass. Pretty sure this is correct though.

if ([indexPath section] == 0) {
    tUser = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)];
    tUser.adjustsFontSizeToFitWidth = YES;
    tUser.textColor = [UIColor blackColor];

    tPass = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)];
    tPass.adjustsFontSizeToFitWidth = YES;
    tPass.textColor = [UIColor blackColor];

    if ([indexPath section] == 0) {
        if ([indexPath row] == 0) {
            tUser.placeholder = @"@JohnAppleseed";
            tUser.keyboardType = UIKeyboardTypeEmailAddress;
            tUser.returnKeyType = UIReturnKeyNext;
        }
        if ([indexPath row] == 1) {
            tPass.placeholder = @"Required";
            tPass.keyboardType = UIKeyboardTypeDefault;
            tPass.returnKeyType = UIReturnKeyDone;
            tPass.secureTextEntry = YES;
        }
    }

    tUser.backgroundColor = [UIColor whiteColor];
    tUser.autocorrectionType = UITextAutocorrectionTypeNo;
    tUser.autocapitalizationType = UITextAutocapitalizationTypeNone;
    tUser.textAlignment = UITextAlignmentLeft;

    tPass.backgroundColor = [UIColor whiteColor];
    tPass.autocorrectionType = UITextAutocorrectionTypeNo;
    tPass.autocapitalizationType = UITextAutocapitalizationTypeNone;
    tPass.textAlignment = UITextAlignmentLeft;

    tUser.clearButtonMode = UITextFieldViewModeNever;
    tPass.clearButtonMode = UITextFieldViewModeNever;

    [tUser setEnabled:YES];
    [tPass setEnabled:YES];

    //[tUser release];
    //[tPass release];
}
if ([indexPath section] == 0) { // Email & Password Section
    if ([indexPath row] == 0) { // Email
        cell.textLabel.text = @"Username";
        [cell addSubview:tUser];
        [tUser setText:[[NSUserDefaults standardUserDefaults] objectForKey:@"twitter_name_preference"]];
    }
    else {
        cell.textLabel.text = @"Password";
        [cell addSubview:tPass];
        [tPass setText:[[NSUserDefaults standardUserDefaults] objectForKey:@"twitter_pass_preference"]];
    }
}
return cell; }

如您所见，这些工作正常，当我加载 UITableView 时，UITextFields 加载到正确的 UITableViewCells 中。但是，正如您所看到的，我拉出了两个 NSUserDefault 对象，它们都放置到相应的 UITextField 中。

但是，然后我将另一个操作附加到导航栏中显示的保存按钮。

-(void)save_clicked: (id) sender {

if ([tPass text] == nil) {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" 
                                                    message:@"There was no password entered, please enter the correct password and try again." 
                                                   delegate:self 
                                          cancelButtonTitle:@"Okay" 
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
}

else {
    NSLog(@"we can do something here soon...");

    //NSString *tUserString = [[NSString alloc] initWithFormat:@"Hello: %@", tUser.text];

    NSLog(@"We saved their username: %@", [tUser text]);
    NSLog(@"We saved their password: %@", [tPass text]);

    // here we will start saving the username and password, then obtaining the authentication shit.



}
}

但是，当我调用这些 NSLogs 时，tUser 返回（null），但 tPass 返回输入的文本。我确信这只是一个简单的语法错误或类似的错误，因为一切（从我的角度来看）看起来都应该有效。尽管如此，事实并非如此。

有人可以帮助我找出 tUser UITextField 出了什么问题以及为什么它不断返回（null）吗？

感谢所有帮助！

Answer 1

每次显示单元格时，您都会添加新的 tUser 和 tPass 文本字段。您应该将单元格创建代码（添加文本字段）保留在 if (cell == nil) 块内，并在该块外部配置这些文本字段。这样，您就不会在每次调用 tableView:cellForRowAtIndexPath: 时添加新的文本字段。