如何在iPhone中将焦点设置到下一个uitextfield？

问题描述

| 我有8个用于密码的uitextfields。每个文本字段均包含一个来自密码的字母。当我键入一个字母，然后按第二个键时，焦点将移至下一个文本字段。但是我希望，当我完成第一个字符的输入后，焦点应移至下一个文本字段，而无需按其他键或按Tab键。我怎样才能做到这一点？有任何示例代码教程吗？我使用的代码如下。

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(Nsstring *)string
{
    [[NSNotificationCenter defaultCenter] addobserver: self selector: @selector(keypressed:) name: UITextFieldTextDidChangeNotification object: nil];
    // Try to find next responder

    UIResponder* nextResponder = [textField.superview viewWithTag:nextTag];
    if (nextResponder) {
        // Found next responder,so set it.
        //nextTag += 1;
        [nextResponder becomeFirstResponder];
        if ([nextResponder tag] == 308) {
            //[self performSelector:@selector(checkPassCode) withObject:nil afterDelay:0.0];
            [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(checkPassCode) userInfo:nil repeats:NO];
            lastResponder = nextResponder;
        }
        return YES;
    } else {
        [textField resignFirstResponder];
        return NO;
    }
}


-(void) keypressed: (NSNotification*) notification
{
    nextTag += 1;
    [[NSNotificationCenter defaultCenter] removeObserver: self name:UITextFieldTextDidChangeNotification object: nil];
}

    

解决方法

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    NSString *finalString = [textField.text stringByReplacingCharactersInRange:range withString:string];

    if ( [finalString length] > 0 ) {
        textField.text = string;

        UIResponder* nextResponder = [textField.superview viewWithTag:(textField.tag + 1)];
        if (nextResponder) {
            [nextResponder becomeFirstResponder];

            // Your code for checking it.
        }

        return NO;
    }

    return YES;
}

希望这可以帮助。 迅捷3.2

func textField(_ textField: UITextField,shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool {
    let finalString: String? = (textField.text? as NSString).replacingCharacters(in: range,with: string)
    if (finalString?.characters.count ?? 0) > 0 {
        textField.text = string
        let nextResponder: UIResponder? = textField.superview?.viewWithTag((textField.tag + 1))
        if nextResponder != nil {
            nextResponder?.becomeFirstResponder()
            // Your code for checking it.
        }
        return false
    }
    return true
}

斯威夫特4.1

func textField(_ textField: UITextField,replacementString string: String) -> Bool {
    let finalString: String? = (textField.text as NSString?)?.replacingCharacters(in: range,with: string)
    if finalString?.count > 0 {
        textField.text = string
        let nextResponder: UIResponder? = textField.superview?.viewWithTag(textField.tag + 1)
        if nextResponder != nil {
            nextResponder?.becomeFirstResponder()
            // Your code for checking it.
        }
        return false
    }
    return true
}

    ,

-(BOOL)textFieldShouldReturn:(UITextField *)textField {

    if (textField ==firstTextField) {
        [secondTextField becomeFirstResponder];
    }else if ( textField == secondTextField){
        [thirdTextField becomeFirstResponder];
    }else if ( textField == thirdTextField){
        [fourthTextField becomeFirstResponder];
    }else{
        [textField resignFirstResponder];
    }
        return YES;
}

    ,尝试在ViewDidLoad中添加此通知，

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(limitTextField:) name:@\"UITextFieldTextDidChangeNotification\" object:txtField1];

- (void)limitTextField:(NSNotification *)note {
    if(txtField1.tag==1)
    {
        if ([[txtField1 text] length] > 1)
        {
           [txtField1 resignFirstResponder];
           [txtField2 becomeFirstResponder];
        }
    }
}