让我对这么多标签表示歉意，因为我觉得有不止一种方法可以让它发挥作用，而且我不确定是什么导致了这个问题。

我有一个 UICollectionView，在单元格中有一个文本字段。文本字段仅使用数字键盘，我使用 How to show "Done" button on iPhone number pad 中发布的解决方案添加了一个取消和完成按钮。 .

代码是

- (void)viewDidLoad
{
[super viewDidLoad];

UIToolbar* numberToolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];
numberToolbar.barStyle = UIBarStyleBlackTranslucent;
numberToolbar.items = @[[[UIBarButtonItem alloc]initWithTitle:@"Cancel" style:UIBarButtonItemStyleBordered target:self action:@selector(cancelNumberPad)],
                     [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil],
                     [[UIBarButtonItem alloc]initWithTitle:@"Apply" style:UIBarButtonItemStyleDone target:self action:@selector(doneWithNumberPad)]];
[numberToolbar sizeToFit];
numberTextField.inputAccessoryView = numberToolbar;
}

-(void)cancelNumberPad{
[numberTextField resignFirstResponder];
numberTextField.text = @"";
}

-(void)doneWithNumberPad{
NSString *numberFromTheKeyboard = numberTextField.text;
[numberTextField resignFirstResponder];
}

我将 done 中的代码修改为

-(void)doneWithNumberPad{
[self.view endEditing:YES];
}

现在我想应用取消按钮使触发工具栏文本字段的文本字段成为 textfield.placeholder。

我尝试在 cancelNumPad 中传递文本字段，但没有成功。所以我尝试了从调用的文本字段中获取选定单元格的方法。通常当我执行 IBAction 时，我可以只声明发件人并使用 superview 来获取选定的单元格，但是由于 barbutton 在工具栏中，我没有运气。

我的 Controller 设置如下。请注意，UItextfield 是在实现中声明的。

@interface MenuViewController () <UITextFieldDelegate>{
UITextField *myTextField;
}

然后我初始化文本字段，文本字段值初始化为 0。

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
static NSString *reuseIdentifier = @"Cell2";
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];
// Configure the cell
myTextField = (UITextField*)[cell viewWithTag:400;
[[myTextField layer] setBorderWidth:1.0f];
[[myTextField layer] setBorderColor:[UIColor blackColor].CGColor];
myTextField.text = [arrayOfQuantities objectAtIndex:indexPath.item];
myTextField.delegate = self;
myTextField.inputAccessoryView = numberToolbar;
}
return cell;
}

这是我的委托(delegate)代码

-(BOOL)textFieldShouldEndEditing:(UITextField *)textField{
BOOL valid;
BOOL max;
NSCharacterSet *alphaNums = [NSCharacterSet decimalDigitCharacterSet];
NSCharacterSet *inStringSet = [NSCharacterSet characterSetWithCharactersInString:textField.text];
valid = [alphaNums isSupersetOfSet:inStringSet];

//maximum of 100
if([textField.text intValue]>=100){
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Can't be more than 100"
                                                    message:@"Please adjust number"
                                                   delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
    max = NO;
}
else{
    max = YES;
}
if (valid && max){
    return YES;
}//not valid
else{
    return NO;
}
}

-(void)textFieldDidEndEditing:(UITextField *)textField{
if (textField.text.length == 0) {
    textField.text = textField.placeholder;
}
textField.placeholder = @"";
UITextField *currentTextField = textField;
UICollectionViewCell *selectedCell = (UICollectionViewCell *)[[currentTextField superview]superview];
UICollectionView *collectionViewForSelection = (UICollectionView *)[selectedCell superview];
NSIndexPath *textFieldIndexPath = [collectionViewForSelection indexPathForCell:selectedCell];
textField.text = [NSString stringWithFormat:@"%d",[textField.text intValue]];
[arrayOfQuantities replaceObjectAtIndex:textFieldIndexPath.item withObject:[NSString stringWithFormat:@"%d",[currentTextField.text intValue]]];
}

- (void)textFieldDidBeginEditing:(UITextField *)textField {
textField.placeholder = textField.text;
textField.text = @"";
}

如何让取消按钮起作用？完成按钮工作正常。

最佳答案

对于那些正在寻找答案的人。在你的 .m 文件中， UITextField *currentTextField;

在文本字段委托(delegate)中

-(void)textFieldDidBeginEditing:(UITextField *)textField{
currentTextField = textField;
UICollectionViewCell *selectedCell = (UICollectionViewCell *)[[currentTextField    superview]superview];
UICollectionView *collectionViewForSelection = (UICollectionView *) [selectedCell superview];
NSIndexPath *textFieldIndexPath = [collectionViewForSelection  indexPathForCell:selectedCell];
//do whatever with your cell after

关于ios - 如何从工具栏xcode ios中的barbutton中的UICollectionField中获取(索引)文本字段，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32029087/