幻灯片转换无法正常工作 flutter

Question

I am using a method keyboardSlide which is being passed into my login_page.dart, the method is using a conditional which will slide the keyboard on and off the screen when keyboardUp is true or false. I have the condition being set to true when I click on the username field, and false when I click on the password field, I pasted part of the code for my login screen below. The problem I am having trouble understanding is how to do the animation automatically, I can hard code it and it will work, but I need to know how to have the animation be rebuilt every time the Boolean is changed from true to false so the keyboard will slide up and down.

Here are the images with and without the keyboard.

SlideTransistion method

SlideTransition keyboardSlide(AnimationController controller1, Widget Keyboard) {
 if (keyboardUp == true) {
   return SlideTransition(
     position: Tween<Offset>(
       begin: Offset(0,1),
       end: Offset(0, 0),
     ).animate(controller1),
     child: Padding(
       padding: const EdgeInsets.only(top: 300),
       child: Container(
         child: Keyboard,
       ),
     ),
   );
 } else {
   return SlideTransition(
     position: Tween<Offset>(
       begin: Offset(0,0),
       end: Offset(0, 1),
     ).animate(controller1),
     child: Padding(
       padding: const EdgeInsets.only(top: 300),
       child: Container(
         child: Keyboard,
       ),
     ),
   );
 }
}

Part of login_page.dart

 @override
  Widget build(BuildContext context) {
    return Material(
      child: Container(
        child: Stack(
          children: <Widget>[
            keyboardSlide(_controller, toggleKeyboard()),
            Positioned(
                top: 652,
                left: 0,
                child: Container(
                    width: 1280,
                    height: 100,
                    decoration: BoxDecoration(
                      image: DecorationImage(
                          image: AssetImage('assets/login/rectangle_112.png'),
                          fit: BoxFit.fitWidth
                      ),
                    )
                )
            ),
            Positioned(
                top: 652,
                left: 930,
                child: Container(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: <Widget>[
                        SizedBox(
                          child: IconButton(
                            padding: EdgeInsets.all(0.0),
                            // iconColor() is grabbing the icon based on the isUserFilled & isPasswordFilled
                            // This will cause the icon to turn from grey to white when both fields are filled
                            icon: Image.asset(iconColor()),
                            onPressed: () {
                              Navigator.pushNamed(context, '/menu');
                            },
                          ),
                        ),
                        Text(
                          'Login',
                          // textColor() is grabbing the color based on the isUserFilled & isPasswordFilled
                          // This will cause the login text to turn from grey to white when both fields are filled
                          style: TextStyle(color: textColor()),
                        ),
                      ],
                    ),
                    width: 350,
                    height: 100,
                    decoration: BoxDecoration(
                      // backgroundColor() is grabbing the color based on the isUserFilled & isPasswordFilled
                      // This will cause the login button to turn from grey to green when both fields are filled
                      color: backgroundColor(),
                    )
                )

            ), Positioned(
                top: userFieldHeight,
                left: 201,
                child: Container(
                    child: TextField(
                      // Checking the UserName textField for user input, returns a boolean to isUserFilled
                     controller: myController1,
                      readOnly: true,
                      showCursor: true,
                      onTap: () {
                        userSelected = true;
                        keyboardUp = true; // This boolean being passed to keyboardSlide
                      },
                      onChanged: (input) {
                        setState(() {
                          (input.isEmpty) ? isUserFilled = false: isUserFilled = true;
                        });
                      },
                      decoration: InputDecoration(
                        border: OutlineInputBorder(),
                      ),
                    ),
                    width: 400,
                    height: 60,
                    decoration: BoxDecoration(
                      color: Color.fromRGBO(255, 255, 255, 1),
                    )
                )
            ), Positioned(
                top: userFieldHeight, // original is 350
                left: 640,
                child: Container(
                    child: TextField(
                      style: TextStyle(fontSize: 24),
                     controller: myController2,
                      readOnly: true,
                      showCursor: true,
                      obscureText: true,
                      onTap: () {
                        userSelected = false;
                        keyboardUp = false; // This boolean being passed to keyboardSlide
                      },
                      // Checking the Password textField for user input, returns a boolean to isPasswordFilled
                      onChanged: (input) {
                        setState(() {
                          (input.isEmpty) ? isPasswordFilled = false: isPasswordFilled = true;
                        });
                      },
                      decoration: InputDecoration(
                        border: OutlineInputBorder(),
                      ),
                    ),

Answer 1

I was actually able to make it work by creating a conditional. If you add a status listener to the controller you can see two values AnimationStatus.completed and AnimationStatus.dismissed. You can set a boolean where if the animation is completed this means the keyboard is up and vice versa. then you can put another conditonal statement inside the onpressed or onTap function which can then toggle the animation. Im not sure if this is the best way to do this, but it does the trick.

_controller.addStatusListener((status) {
      print(status);
      if (status == AnimationStatus.completed){
        keyboardUp = true;
      }
      if (status == AnimationStatus.dismissed) {
        keyboardUp = false;
      }
    });

TextField(
                      // Checking the UserName textField for user input, returns a boolean to isUserFilled
                     controller: userNameController,
                      readOnly: true,
                      showCursor: true,
                      onTap: () {
                       setState(() {
                         keyboardUp ? _controller.reverse() : _controller.forward();
                       });
                      },
                      onChanged: (input) {
                        setState(() {
                          (input.isEmpty) ? isUserFilled = false: isUserFilled = true;
                        });
                      },
                      decoration: InputDecoration(
                        border: OutlineInputBorder(),
                      ),
                    ),