聚焦编辑文本时从编辑文本中删除文本

时间：2021-06-01 06:57:59

标签： android kotlin fragment

我想在编辑文本以编程方式聚焦时删除文本，当我尝试这样做时，片段类会抛出空指针异常。

我使用的设计是 Material Text Input Layout，当我在文本输入布局中设置提示时，提示在 TextInputLayout 周围的框中向上移动，我不想要那样。我只想要盒子，

所以我将文本设置为 XML 文件的 EditTextField 中的提示，我想在用户单击 EditText 或 EditText 聚焦时删除文本。

这是为了更好地理解问题而录制的屏幕

https://www.youtube.com/watch?v=6EgBymObb4A

这是布局 XML 文件

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".screens.fragments.login_fragment"
    android:background="@color/black"
    android:focusable="true"
    android:focusableInTouchMode="true">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="center">

    <TextView
        android:id="@+id/txt_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Login"
        android:textAllCaps="false"
        android:fontFamily="@font/raleway_semi_bold"
        android:textColor="@color/white"
        android:textSize="32sp"
        android:letterSpacing="0.1"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintBottom_toTopOf="@id/txt_login_des"
        android:layout_marginStart="20dp"
        android:layout_marginTop="10dp"/>

    <TextView
        android:id="@+id/txt_login_des"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Enter Your Credintials to get access"
        android:textColor="#9CFFFFFF"
        android:fontFamily="@font/raleway_medium"
        android:textSize="12sp"
        app:layout_constraintTop_toBottomOf="@id/txt_login"
        app:layout_constraintLeft_toLeftOf="parent"
        android:layout_marginTop="15dp"
        android:layout_marginStart="20dp"/>

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/user_id_feild"
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_marginStart="20dp"
        android:layout_marginEnd="20dp"
        android:layout_marginTop="30dp"
        app:boxCornerRadiusBottomEnd="8dp"
        app:boxCornerRadiusBottomStart="8dp"
        app:boxCornerRadiusTopEnd="8dp"
        app:boxCornerRadiusTopStart="8dp"
        app:boxStrokeColor="@color/white"
        app:boxStrokeErrorColor="#FF0000"
        app:boxStrokeWidth="1dp"
        android:layout_marginBottom="20dp"
        app:layout_constraintTop_toBottomOf="@id/txt_login_des"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toTopOf="@id/password_feild">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/LoginUserIDField"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:focusedByDefault="false"
            android:text="User ID"
            android:textColor="#74FFFFFF"
            android:drawableStart="@drawable/custom_user_edit_txt_input"
            android:drawablePadding="10dp"
            android:padding="10dp"/>

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/password_feild"
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_marginStart="20dp"
        android:layout_marginEnd="20dp"
        android:layout_marginBottom="40dp"
        app:boxCornerRadiusBottomEnd="8dp"
        app:boxCornerRadiusBottomStart="8dp"
        app:boxCornerRadiusTopEnd="8dp"
        app:boxCornerRadiusTopStart="8dp"
        app:boxStrokeColor="@color/white"
        app:boxStrokeErrorColor="#FF0000"
        app:boxStrokeWidth="1dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toTopOf="@id/btn_signIn">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/UserLoginPassword"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="•••••••••••••"
            android:drawableStart="@drawable/custom_pass_txt_input"
            android:drawablePadding="10dp"
            android:textColor="#74FFFFFF"
            android:padding="10dp"/>

    </com.google.android.material.textfield.TextInputLayout>


    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_signIn"
        style="@style/Widget.MaterialComponents.Button.OutlinedButton"
        android:layout_width="250dp"
        android:layout_height="60dp"
        android:layout_marginBottom="10dp"
        android:backgroundTint="@color/white"
        android:text="Sign In"
        android:textAllCaps="false"
        android:textColor="@color/black"
        app:rippleColor="@color/black"
        app:strokeColor="@color/white"
        app:strokeWidth="1dp"
        app:layout_constraintBottom_toTopOf="@id/btn_register"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"/>

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_register"
        style="@style/Widget.MaterialComponents.Button.OutlinedButton"
        android:layout_width="250dp"
        android:layout_height="60dp"
        android:layout_marginBottom="50dp"
        android:text="Register"
        android:textAllCaps="false"
        android:textColor="@color/white"
        app:rippleColor="@color/black"
        app:strokeColor="@color/white"
        app:strokeWidth="1dp"
        app:layout_constraintBottom_toTopOf="@id/bottom_fab_btns_lyt"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"/>

    <LinearLayout
        android:id="@+id/bottom_fab_btns_lyt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="20dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintLeft_toLeftOf="parent">

         <com.google.android.material.button.MaterialButton
             android:id="@+id/btn_facebook"
             style="@style/Widget.MaterialComponents.Button.OutlinedButton.Icon"
             android:layout_width="50dp"
             android:layout_height="50dp"
             app:strokeWidth="1dp"
             app:strokeColor="@color/white"
             app:icon="@drawable/icons8_facebook"
             app:iconTintMode="add"
             app:iconSize="24dp"
             app:iconTint="#000000"
             app:iconPadding="0dp"
             android:background="@drawable/fab_background"
             android:backgroundTintMode="add"
             app:backgroundTintMode="add"
             app:rippleColor="@color/white"/>

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_google"
        style="@style/Widget.MaterialComponents.Button.OutlinedButton.Icon"
        android:layout_width="50dp"
        android:layout_height="50dp"
        app:strokeWidth="1dp"
        app:strokeColor="@color/white"
        app:icon="@drawable/google_cute_icon"
        app:iconTintMode="add"
        app:iconSize="24dp"
        app:iconTint="#000000"
        app:iconPadding="0dp"
        android:layout_marginStart="20dp"
        android:layout_marginEnd="20dp"
        android:background="@drawable/fab_background"
        android:backgroundTintMode="add"
        app:backgroundTintMode="add"
        app:rippleColor="@color/white"/>

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_twitter"
        style="@style/Widget.MaterialComponents.Button.OutlinedButton.Icon"
        android:layout_width="50dp"
        android:layout_height="50dp"
        app:strokeWidth="1dp"
        app:strokeColor="@color/white"
        app:icon="@drawable/google_cute_icon"
        app:iconTintMode="add"
        app:iconSize="24dp"
        app:iconTint="#000000"
        app:iconPadding="0dp"
        android:background="@drawable/fab_background"
        android:backgroundTintMode="add"
        app:backgroundTintMode="add"
        app:rippleColor="@color/white"/>

    </LinearLayout>

        </androidx.constraintlayout.widget.ConstraintLayout>
    </ScrollView>


</androidx.constraintlayout.widget.ConstraintLayout>

片段类

package com.ak_applications.kottry.screens.fragments

import android.content.res.ColorStateList
import android.graphics.Color
import android.graphics.drawable.AnimatedVectorDrawable
import android.graphics.drawable.Drawable
import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import androidx.fragment.app.Fragment
import android.view.View
import android.view.ViewGroup
import com.ak_applications.kottry.R
import com.ak_applications.kottry.databinding.FragmentLoginFragmentBinding

class login_fragment : Fragment(R.layout.fragment_login_fragment) {


    private var _binding: FragmentLoginFragmentBinding? = null
    private val binding get() = _binding!!


    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
       _binding = FragmentLoginFragmentBinding.inflate(inflater, container, false)
        val view = binding.root
        return view
    }


    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

    }




        override fun onDestroy() {
            super.onDestroy()
            _binding = null
        }
}

我试过了

if(binding.LoginUserFeild.isFocused)
{
 binding.LoginUserFeild.setText("")
 binding.LoginUserFeild.setTextColor(Color.parseColor("#ffffff"))
}

还有

if(binding.LoginUserFeild.isFocused)
{
 binding.userLoginfeild.setHint("") // which is TextInputLayout.
}

我也使用滚动布局作为片段的父布局，但正如您在屏幕录制中看到的那样，当用户单击 EditText Feild 时，布局转到顶部，但用户向下滚动，而 EditText 选择了布局不会一路向上，布局缺少一些我不知道的东西。

我是 Android 新手，请在这里帮助我。

1 个答案:

答案 0 :(得分：4)

binding.LoginUserFeild.setOnFocusChangeListener { _, hasFocus ->
    if (hasFocus) {
      binding.LoginUserFeild.setText("")      
    }
}
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