适用于iPad App的自定义数字键盘

Question

我正在为iOS 8上运行的iPad创建一个内部应用程序（不适用于应用程序商店），其中一个要求是复制iPad解锁/ PIN码输入数字键盘的自定义键盘。

我将自定义数字键盘基于此项目：https://github.com/lnafziger/Numberpad

在我的项目中，我向UIViewController添加了一个新的UIView，以便我可以复制下面输入4位数PIN码时出现的点：

我的问题是，当点按它们时，我无法正确定位数字。我的目标是，当我点击数字0到9时，第一个点击将该数字放入第一个文本框，第二个点击进入第二个等等。但我无法在数字键盘上点击以在4中的任何一个中注册可用的UITextFields。

[编辑]

到目前为止，这是代码的一部分：

#pragma mark - KEYPAD IBACTIONS

// A number (0-9) was just pressed on the number pad
// Note that this would work just as well with letters or any other character and is not limited to numbers.
- (IBAction)numberpadNumberPressed:(UIButton *)sender {
    if (self.targetTextInput) {
        NSString *numberPressed  = sender.titleLabel.text;
        if ([numberPressed length] > 0) {
            UITextRange *selectedTextRange = self.targetTextInput.selectedTextRange;
            if (selectedTextRange) {
                [self textInput:self.targetTextInput replaceTextAtTextRange:selectedTextRange withString:numberPressed];
            }
        }
    }
}

// The delete button was just pressed on the number pad
- (IBAction)numberpadDeletePressed:(UIButton *)sender {
    if (self.targetTextInput) {
        UITextRange *selectedTextRange = self.targetTextInput.selectedTextRange;
        if (selectedTextRange) {
            // Calculate the selected text to delete
            UITextPosition  *startPosition  = [self.targetTextInput positionFromPosition:selectedTextRange.start offset:-1];
            if (!startPosition) {
                return;
            }
            UITextPosition  *endPosition    = selectedTextRange.end;
            if (!endPosition) {
                return;
            }
            UITextRange     *rangeToDelete  = [self.targetTextInput textRangeFromPosition:startPosition
                                                                               toPosition:endPosition];

            [self textInput:self.targetTextInput replaceTextAtTextRange:rangeToDelete withString:@""];
        }
    }
}

// The clear button was just pressed on the number pad
- (IBAction)numberpadClearPressed:(UIButton *)sender {
    if (self.targetTextInput) {
        UITextRange *allTextRange = [self.targetTextInput textRangeFromPosition:self.targetTextInput.beginningOfDocument
                                                                     toPosition:self.targetTextInput.endOfDocument];

        [self textInput:self.targetTextInput replaceTextAtTextRange:allTextRange withString:@""];
    }
}

// The done button was just pressed on the number pad
- (IBAction)numberpadDonePressed:(UIButton *)sender {
    if (self.targetTextInput) {
        [self.targetTextInput resignFirstResponder];
    }
}

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
    return YES;
}

- (BOOL)textViewShouldEndEditing:(UITextView *)textView
{
    return YES;
}

// Replace the text of the textInput in textRange with string if the delegate approves
- (void)textInput:(id <UITextInput>)textInput replaceTextAtTextRange:(UITextRange *)textRange withString:(NSString *)string {
    if (textInput) {
        if (textRange) {
            // Calculate the NSRange for the textInput text in the UITextRange textRange:
            int startPos                    = [textInput offsetFromPosition:textInput.beginningOfDocument
                                                                 toPosition:textRange.start];
            int length                      = [textInput offsetFromPosition:textRange.start
                                                                 toPosition:textRange.end];
            NSRange selectedRange           = NSMakeRange(startPos, length);

            if ([self textInput:textInput shouldChangeCharactersInRange:selectedRange withString:string]) {
                // Make the replacement:
                [textInput replaceRange:textRange withText:string];
            }
        }
    }
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSString *passcode = [textField text];
    passcode = [passcode stringByReplacingCharactersInRange:range withString:string];

    switch ([passcode length]) {
        case 0:
            self.txtBulletField0.text = nil;
            self.txtBulletField1.text = nil;
            self.txtBulletField2.text = nil;
            self.txtBulletField3.text = nil;
            break;
        case 1:
            self.txtBulletField0.text = @"*";
            self.txtBulletField1.text = nil;
            self.txtBulletField2.text = nil;
            self.txtBulletField3.text = nil;
            break;
        case 2:
            self.txtBulletField0.text = @"*";
            self.txtBulletField1.text = @"*";
            self.txtBulletField2.text = nil;
            self.txtBulletField3.text = nil;
            break;
        case 3:
            self.txtBulletField0.text = @"*";
            self.txtBulletField1.text = @"*";
            self.txtBulletField2.text = @"*";
            self.txtBulletField3.text = nil;
            break;
        case 4:
            self.txtBulletField0.text = @"*";
            self.txtBulletField1.text = @"*";
            self.txtBulletField2.text = @"*";
            self.txtBulletField3.text = @"*";

            // Notify delegate a little later so we have a chance to show the 4th bullet
            [self performSelector:@selector(notifyDelegate:) withObject:passcode afterDelay:0];

            return NO;

            break;
        default:
            break;
    }

在原始项目中，数字键盘指向一个UITextField并将所有数字抽头放入其中。现在我想让它自动在我的4个UITextField之间移动（一个UITextField应该只接受1个字符，然后移动到下一个UITextField）。 numberpadNumberPressed方法似乎根本不会触发更新文本字段。

[结束编辑]

我该怎么做？

Answer 1

这可能很简单。

只需保留已在一个可变字符串变量中点击的数字。按下某个键后，添加下一个数字。如果按下删除键，则删除最后一个号码（如果有）。这应该很容易。 E.g。

if (pinString.length < 4) {
   [pinString appendString:sender.titleLabel.text]
}

和

if (pinString.length) {
   [pinString deleteCharactersInRange:NSMakeRange(pinString.length-1,1)];
}

您没有在文本字段中编辑数字，因此您应该使用标签。在下文中，我假设您已为其提供了标记101，102，103和104。

然后就这样做：

for (UILabel *label in theFourTextLabels) {
   label.text = label.tag - 100 > pinString.length ? "" : "*";
}