you can use this

private fun showPasswordSwitch(checked: Boolean) {

    registerBinding.registerActivityEditTextPassword.also {
        // Password hide-show
        it.inputType =
            if (checked) TEXT_PASSWORD_SHOW else TEXT_PASSWORD_HIDE
           
    }
}
const val TEXT_PASSWORD_SHOW = InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD

const val TEXT_PASSWORD_HIDE = InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_PASSWORD

我所做的是

创建一个编辑文本视图和一个普通文本视图 通过使用约束布局使它们相互重叠(就像Facebook应用登录屏幕一样) 将onClickListener附加到普通文本视图，以便它相应地改变编辑文本视图的输入类型(可见/不可见)

你可以看看这个视频，了解更详细的步骤和解释https://youtu.be/md3eVaRzdIM

希望能有所帮助。

显示:

editText.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);

隐藏:

editText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);

在这些之后，光标被重置，所以:

editText.setSelection(editText.length());

if (inputPassword.getTransformationMethod() == PasswordTransformationMethod.getInstance()) {
 //password is visible
                inputPassword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
            }
else if(inputPassword.getTransformationMethod() == HideReturnsTransformationMethod.getInstance()) {
 //password is hidden
                inputPassword.setTransformationMethod(PasswordTransformationMethod.getInstance());
            }

在XML中这样做

    <LinearLayout
          android:layout_height="wrap_content"
          android:layout_width="fill_parent"
          android:orientation="vertical"
          >
          <RelativeLayout
              android:id="@+id/REFReLayTellFriend"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="horizontal"
              >
          <EditText
              android:id="@+id/etpass1"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:background="@android:color/transparent"
              android:bottomLeftRadius="10dp"
              android:bottomRightRadius="50dp"
              android:fontFamily="@font/frutiger"
              android:gravity="start"
              android:inputType="textPassword"
              android:hint="@string/regpass_pass1"
              android:padding="20dp"
              android:paddingBottom="10dp"
              android:textColor="#000000"
              android:textColorHint="#d3d3d3"
              android:textSize="14sp"
              android:topLeftRadius="10dp"
              android:topRightRadius="10dp"/>
              <ImageButton
                  android:id="@+id/imgshowhide1"
                  android:layout_width="40dp"
                  android:layout_height="20dp"
                  android:layout_marginTop="20dp"
                  android:layout_marginRight="10dp"
                  android:background="@drawable/showpass"
                  android:layout_alignRight="@+id/etpass1"/>
          </RelativeLayout>    

 boolean show=true;
 //on image click inside password do this
 if(show){
                imgshowhide2.setBackgroundResource(0);
                imgshowhide2.setBackgroundResource(R.drawable.hide);
                etpass2.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);
                etpass2.setSelection(etpass2.getText().length());

                show=false;
            }else{
                imgshowhide2.setBackgroundResource(0);
                imgshowhide2.setBackgroundResource(R.drawable.showpass);
                //etpass1.setInputType(InputType.TYPE_TEXT);
                etpass2.setInputType(InputType.TYPE_CLASS_TEXT |
                        InputType.TYPE_TEXT_VARIATION_PASSWORD);
                etpass2.setSelection(etpass2.getText().length());
                show=true;
            }

用复选框显示和隐藏密码Edit_Text

XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:inputType="textPassword"
        android:id="@+id/edtPass"
        android:textSize="20dp"
        android:hint="password"
        android:padding="20dp"
        android:background="#efeaea"
        android:layout_width="match_parent"
        android:layout_margin="20dp"
        android:layout_height="wrap_content" />

    <CheckBox
        android:background="#ff4"
        android:layout_centerInParent="true"
        android:textSize="25dp"
        android:text="show password"
        android:layout_below="@id/edtPass"
        android:id="@+id/showPassword"
        android:layout_marginTop="20dp"
        android:layout_width="wrap_content"
        android:gravity="top|right"
        android:layout_height="wrap_content" />

</RelativeLayout>

java代码

package com.example.root.sql2;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatCheckBox;
import android.support.v7.widget.Toolbar;
import android.text.method.HideReturnsTransformationMethod;
import android.text.method.PasswordTransformationMethod;
import android.view.View;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;

public class password extends AppCompatActivity {


    EditText password;
    CheckBox show_hide_password;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.hide);
        findViewById();
        show_hide_pass();



    }//end onCreate



    public void show_hide_pass(){
        show_hide_password.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (!b){
                    // hide password
                    password.setTransformationMethod(PasswordTransformationMethod.getInstance());

                }else{
                    // show password
                    password.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
                }
            }
        });
    } // end show_hide_pass




    public void findViewById(){ //  find ids ui and
        password = (EditText) findViewById(R.id.edtPass);
        show_hide_password = (CheckBox) findViewById(R.id.showPassword);
    }//end findViewById



}// end class