一个很好的解决方案。设置一个按钮，然后使用下面的代码:

public void showPassword(View v)
{

    TextView showHideBtnText = (TextView) findViewById(R.id.textView1);

    if(showHideBtnText.getText().toString().equals("Show Password")){
        password.setTransformationMethod(null);
        showHideBtnText.setText("Hide");
    } else{
        password.setTransformationMethod(new PasswordTransformationMethod());
        showHideBtnText.setText("Show Password");
    }


}

private boolean isPasswordVisible;

private TextInputEditText firstEditText;

...

firstEditText = findViewById(R.id.et_first);

...

    private void togglePassVisability() {
    if (isPasswordVisible) {
        String pass = firstEditText.getText().toString();
        firstEditText.setTransformationMethod(PasswordTransformationMethod.getInstance());
        firstEditText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
        firstEditText.setText(pass);
        firstEditText.setSelection(pass.length());           
    } else {
        String pass = firstEditText.getText().toString();
        firstEditText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
        firstEditText.setInputType(InputType.TYPE_CLASS_TEXT);
        firstEditText.setText(pass);
        firstEditText.setSelection(pass.length());
    }
    isPasswordVisible= !isPasswordVisible;
}

你可以使用app:passwordToggleEnabled="true"

下面是一个例子

<android.support.design.widget.TextInputLayout
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:passwordToggleEnabled="true"
        android:textColorHint="@color/colorhint"
        android:textColor="@color/colortext">

你试过setTransformationMethod吗?它继承自TextView，并希望TransformationMethod作为参数。

你可以在这里找到更多关于TransformationMethods的信息。

它还有一些很酷的功能，比如字符替换。

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

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