Ios 目标C-自动从textfield导航到textfield

我需要有3个文本字段，每个文本字段应该只输入1个数字（文本字段的最大长度是1）。

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我的问题是，在用户输入数字后，如何从textfield1、textfield2、textfield3自动导航？

实现

textField:shouldchangeCharactersRange:replacementString:

delegate方法。根据在文本字段中输入的文本，您可以在下一个文本字段中调用

becomeFirstResponder

---

记住，你想做的事情有很多复杂因素。如果用户将一组文本粘贴到文本字段中，会发生什么情况？如果用户返回到已经有值的文本字段，会发生什么情况？

实现

文本字段：shouldChangeCharactersRange:replacementString:

委托方法。根据在文本字段中输入的文本，您可以在下一个文本字段中调用

becomeFirstResponder

---

记住，你想做的事情有很多复杂因素。如果用户将一组文本粘贴到文本字段中，会发生什么情况？如果用户返回到已经有值的文本字段，会发生什么情况？

实现

文本字段：shouldChangeCharactersRange:replacementString:

委托方法。根据在文本字段中输入的文本，您可以在下一个文本字段中调用

becomeFirstResponder

---

记住，你想做的事情有很多复杂因素。如果用户将一组文本粘贴到文本字段中，会发生什么情况？如果用户返回到已经有值的文本字段，会发生什么情况？

实现

文本字段：shouldChangeCharactersRange:replacementString:

委托方法。根据在文本字段中输入的文本，您可以在下一个文本字段中调用

becomeFirstResponder

---

记住，你想做的事情有很多复杂因素。如果用户将一组文本粘贴到文本字段中，会发生什么情况？如果用户返回到已经有值的文本字段，会发生什么情况？

您可以使用以下代码：

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  if (theTextField == textField1 && YOUR_CONDITION_TO_COMPLETION_OF_EDITING){    
     [textField2 becomeFirstResponder];    
  }
}

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为其他文本字段添加类似的条件

您可以使用以下代码：

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  if (theTextField == textField1 && YOUR_CONDITION_TO_COMPLETION_OF_EDITING){    
     [textField2 becomeFirstResponder];    
  }
}

---

为其他文本字段添加类似的条件

您可以使用以下代码：

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  if (theTextField == textField1 && YOUR_CONDITION_TO_COMPLETION_OF_EDITING){    
     [textField2 becomeFirstResponder];    
  }
}

---

为其他文本字段添加类似的条件

您可以使用以下代码：

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  if (theTextField == textField1 && YOUR_CONDITION_TO_COMPLETION_OF_EDITING){    
     [textField2 becomeFirstResponder];    
  }
}

---

为其他文本字段添加类似条件也

将textfield1、textfield2、textfield3的标记分别设置为0、1和2，然后尝试以下代码

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ((textField.text.length == 0 && string.length == 1 && [[NSCharacterSet decimalDigitCharacterSet] isSupersetOfSet:[NSCharacterSet characterSetWithCharactersInString:string]]) || string.length == 0) {
       // Try to find next responder
        if (!(string.length == 0))
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        return YES;
    } else {
        if (textField.text.length == 1) {
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        }
        return NO;
    }
}

- (void)changeResponder:(UITextField *)textField {
    NSInteger nextTag = textField.tag + 1;
    UIResponder *nextResponder = [textField.superview viewWithTag:nextTag];
    if (nextResponder) {
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        // Not found, so remove keyboard.
        [textField resignFirstResponder];
    }
}

---

将textfield1、textfield2、textfield3的标记分别设置为0、1和2，然后尝试以下代码

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ((textField.text.length == 0 && string.length == 1 && [[NSCharacterSet decimalDigitCharacterSet] isSupersetOfSet:[NSCharacterSet characterSetWithCharactersInString:string]]) || string.length == 0) {
       // Try to find next responder
        if (!(string.length == 0))
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        return YES;
    } else {
        if (textField.text.length == 1) {
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        }
        return NO;
    }
}

- (void)changeResponder:(UITextField *)textField {
    NSInteger nextTag = textField.tag + 1;
    UIResponder *nextResponder = [textField.superview viewWithTag:nextTag];
    if (nextResponder) {
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        // Not found, so remove keyboard.
        [textField resignFirstResponder];
    }
}

---

将textfield1、textfield2、textfield3的标记分别设置为0、1和2，然后尝试以下代码

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ((textField.text.length == 0 && string.length == 1 && [[NSCharacterSet decimalDigitCharacterSet] isSupersetOfSet:[NSCharacterSet characterSetWithCharactersInString:string]]) || string.length == 0) {
       // Try to find next responder
        if (!(string.length == 0))
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        return YES;
    } else {
        if (textField.text.length == 1) {
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        }
        return NO;
    }
}

- (void)changeResponder:(UITextField *)textField {
    NSInteger nextTag = textField.tag + 1;
    UIResponder *nextResponder = [textField.superview viewWithTag:nextTag];
    if (nextResponder) {
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        // Not found, so remove keyboard.
        [textField resignFirstResponder];
    }
}

---

将textfield1、textfield2、textfield3的标记分别设置为0、1和2，然后尝试以下代码

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ((textField.text.length == 0 && string.length == 1 && [[NSCharacterSet decimalDigitCharacterSet] isSupersetOfSet:[NSCharacterSet characterSetWithCharactersInString:string]]) || string.length == 0) {
       // Try to find next responder
        if (!(string.length == 0))
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        return YES;
    } else {
        if (textField.text.length == 1) {
            [self performSelector:@selector(changeResponder:) withObject:textField afterDelay:0.2];
        }
        return NO;
    }
}

- (void)changeResponder:(UITextField *)textField {
    NSInteger nextTag = textField.tag + 1;
    UIResponder *nextResponder = [textField.superview viewWithTag:nextTag];
    if (nextResponder) {
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        // Not found, so remove keyboard.
        [textField resignFirstResponder];
    }
}

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