使用下面的代码

    val hidePasswordMethod = PasswordTransformationMethod()
    showOrHidePasswordButton.setOnClickListener {
        passwordEditText.apply {
            transformationMethod =
                if (transformationMethod is PasswordTransformationMethod) 
                   null //shows password
               else 
                   hidePasswordMethod //hides password
        }
    }

并确保你把它添加到你的密码编辑文本在布局

    android:inputType="textPassword"

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

非常简单的形式:

private fun updatePasswordVisibility(editText: AppCompatEditText) {
        if (editText.transformationMethod is PasswordTransformationMethod) {
            editText.transformationMethod = null
        } else {
            editText.transformationMethod = PasswordTransformationMethod()
        }
        editText.setSelection(editText.length())
    }

希望能有所帮助。

您必须询问当前文本是否已经显示了圆点，函数PasswordTransformationMethod.getInstance()允许您这样做。

这是我在kotlin中的函数:

        fun hideAndShowPassword(editText: EditText, indicator: ImageView) {

        if (editText.transformationMethod == PasswordTransformationMethod.getInstance()) {
            editText.transformationMethod = HideReturnsTransformationMethod.getInstance()
            indicator.setImageDrawable(
                ContextCompat.getDrawable(
                    editText.context,
                    R.drawable.eye
                )
            )
            indicator.imageTintList =
                ContextCompat.getColorStateList(editText.context, R.color.colorTintIcons)
        } else {
            editText.transformationMethod = PasswordTransformationMethod.getInstance()
            indicator.setImageDrawable(
                ContextCompat.getDrawable(
                    editText.context,
                    R.drawable.eye_off
                )
            )
            indicator.imageTintList =
                ContextCompat.getColorStateList(editText.context, R.color.colorTintIcons)
        }

        editText.setSelection(editText.text.length)
    }

只需在Xml文件中创建一个复选框

然后简单的用Java代码编写这个函数

checkbox = findViewById(R.id.checkbox);
        checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked){

                if (isChecked) {
                    password.setTransformationMethod(null);
                }
                else{
                    password.setTransformationMethod(new PasswordTransformationMethod());
                }
            }

        });

使用下面的代码

    val hidePasswordMethod = PasswordTransformationMethod()
    showOrHidePasswordButton.setOnClickListener {
        passwordEditText.apply {
            transformationMethod =
                if (transformationMethod is PasswordTransformationMethod) 
                   null //shows password
               else 
                   hidePasswordMethod //hides password
        }
    }

并确保你把它添加到你的密码编辑文本在布局

    android:inputType="textPassword"