android - 无法从 Android 中的 EditText 检索输入文本

Question

我无法从 Android 中的 EditText 检索输入文本。 这是我的代码:

package com.example.fragments2

import ...
import com.example.fragments2.databinding.FragmentLoginPageBinding
class LoginPage : Fragment()
{

    lateinit var loginId:EditText
    lateinit var password:EditText
    lateinit var loginButton:Button

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View?

        {
            var binding:FragmentLoginPageBinding = DataBindingUtil.inflate(inflater,R.layout.fragment_login_page,container,false)
            var view  = binding.root
            loginId = view.findViewById(R.id.edittext_userid)
            password = view.findViewById(R.id.edittext_password)
            loginButton = view.findViewById(R.id.button_login)

            val text1: String = loginId.text.toString()
            val text2:String = password.text.toString()

        loginButton.setOnClickListener {
               Navigation.findNavController(it).navigate(LoginPageDirections.actionLoginPageToMainPage(text1,text2))
               Toast.makeText(context,text1,Toast.LENGTH_SHORT).show() //<-- shows empty string
           }

            return view
        }


}

Text1、Text2 的值始终保持为 "" 。 这段代码有什么问题？

Answer 1

我认为点击回调不会采用您的 TextViews 的正确实例。尝试在点击按钮中获取这些值:

class LoginPage : Fragment()
{

    lateinit var loginId:EditText
    lateinit var password:EditText
    lateinit var loginButton:Button

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View?

        {
            var binding:FragmentLoginPageBinding = DataBindingUtil.inflate(inflater,R.layout.fragment_login_page,container,false)
            var view  = binding.root
            loginId = view.findViewById(R.id.edittext_userid)
            password = view.findViewById(R.id.edittext_password)
            loginButton = view.findViewById(R.id.button_login)

            loginButton.setOnClickListener {
                val text1: String = loginId.text.toString()
                val text2: String = password.text.toString()
                Navigation.findNavController(it).navigate(LoginPageDirections.actionLoginPageToMainPage(text1,text2))
                Toast.makeText(context,text1,Toast.LENGTH_SHORT).show() //<-- shows empty string
           }

           return view
        }
}

注意:也许您必须使用runOnUiMainThread() 调用Toast.makeText。我已经有一段时间没有这样做了。

this.runOnUiThread {
     Toast.makeText(context,text1,Toast.LENGTH_SHORT).show() //<-- shows empty string
}