如何在表格单元格中创建UITextField成为第一响应者？

Question

如果我有一系列表格单元格，每个表格单元格都有一个文本字段，我将如何使特定的文本字段成为第一个响应者？

Answer 1

// Customize the appearance of table view cells.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) 
{
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    UITextField *textField = [[UitextField alloc] init];
 ...
     textField.delegate = self;
     textField.tag = indexPath.row;
     [cell addSubView:textField];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    [textField resignFirstResponder];
    return YES;
}

i hope this may help you...

Answer 2

Swift 4 :To make textfield the first responder in tableview simply add this extension to tableView:

extension UITableView {
    func becomeFirstResponderTextField() {
        outer: for cell in visibleCells {
            for view in cell.contentView.subviews {
                if let textfield = view as? UITextField {
                    textfield.becomeFirstResponder()
                    break outer
                }
            }
        }
    }
}

Then in viewDidAppear() call becomeFirstResponderTextField():

func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    tableView.becomeFirstResponderTextField()
}

Note: I am considered visibleCells to search through

Answer 3

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{

static NSString *CellIdentifier = @"Cell";

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

}
if(indexPath.row==1)
    {
        [cell.txtField becomeFirstResponder];
    }
return cell;
}

Above code make selected(becomeFirstResponder) textfield in second UItableView cell.Thanks

Answer 4

If you want the text field to become first responder after loading the table view,

NSIndexPath *indexPath = /* Index path of the cell containg the text field */;
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
// Assuming that you have set the text field's "tag" to 100
UITextField *textField = (UITextField *)[cell viewWithTag:100];
// Make it the first responder
[textField becomeFirstResponder];

Answer 5

UITextField继承自UIResponder，后者实现了becomeFirstResponder消息。