ios - iPad 应用程序的自定义数字键盘

Question

我正在为在 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。

我的自定义数字键盘基于这个项目:https://github.com/lnafziger/Numberpad

在我的项目中，我向 UIViewController 添加了一个新的 UIView，这样我就可以复制在键入 4 位 PIN 码时出现的点，如下所示:

我的问题是，当我点击数字时，我无法正确定位数字。我的目标是，当我点击数字 0 到 9 时，第一次点击会将该数字放入第一个文本框，第二次点击会放入第二个文本框，依此类推。但是我无法在数字键盘上点击以在 4 个中的任何一个中注册可用的 UITextFields。

[编辑]

这是到目前为止的那部分代码:

#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;
    }

在最初的项目中，数字键盘以一个 UITextField 为目标，并将所有的数字点击放在其中。现在我想让它在我的 4 个 UITextField 之间自动移动(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

这可以很简单。

只需将已点击的数字保存在一个 可变字符串变量中。当按下一个键时，添加下一个数字。如果按下删除键，则删除最后一个数字(如果有)。那应该很容易。例如

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

和

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

您没有编辑文本字段中的数字，因此您应该改用标签。在下文中，我假设您已经为他们提供了标签 101 , 102 , 103和 104 .

然后就做这样的事情:

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