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)
    }

这是我的解决方案没有使用TextInputEditText和转换方法。

XML

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            style="@style/FormLabel"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/username" />

        <EditText
            android:id="@+id/loginUsername"
            style="@style/EditTextStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:drawableLeft="@drawable/ic_person_outline_black_24dp"
            android:drawableStart="@drawable/ic_person_outline_black_24dp"
            android:inputType="textEmailAddress"
            android:textColor="@color/black" />

        <TextView
            style="@style/FormLabel"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:text="@string/password" />

        <EditText
            android:id="@+id/loginPassword"
            style="@style/EditTextStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:drawableEnd="@drawable/ic_visibility_off_black_24dp"
            android:drawableLeft="@drawable/ic_lock_outline_black_24dp"
            android:drawableRight="@drawable/ic_visibility_off_black_24dp"
            android:drawableStart="@drawable/ic_lock_outline_black_24dp"
            android:inputType="textPassword"
            android:textColor="@color/black" />
    </LinearLayout>

Java代码

boolean VISIBLE_PASSWORD = false;  //declare as global variable befor onCreate() 
loginPassword = (EditText)findViewById(R.id.loginPassword);
loginPassword.setOnTouchListener(new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            final int DRAWABLE_LEFT = 0;
            final int DRAWABLE_TOP = 1;
            final int DRAWABLE_RIGHT = 2;
            final int DRAWABLE_BOTTOM = 3;

            if (event.getAction() == MotionEvent.ACTION_UP) {
                if (event.getRawX() >= (loginPassword.getRight() - loginPassword.getCompoundDrawables()[DRAWABLE_RIGHT].getBounds().width())) {
                    // your action here
                    //Helper.toast(LoginActivity.this, "Toggle visibility");
                    if (VISIBLE_PASSWORD) {
                        VISIBLE_PASSWORD = false;
                        loginPassword.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
                        loginPassword.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_lock_outline_black_24dp, 0, R.drawable.ic_visibility_off_black_24dp, 0);
                    } else {
                        VISIBLE_PASSWORD = true;
                        loginPassword.setInputType(InputType.TYPE_CLASS_TEXT);
                        loginPassword.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_lock_outline_black_24dp, 0, R.drawable.ic_visibility_black_24dp, 0);
                    }
                    return false;
                }
            }
            return false;
        }
    });

根据这个来源，如果你已经将你的项目迁移到AndroidX，那么你可以替换

编译”com.android.support:设计:24.2.0”

与

实现“com.google.android.material:材料:1.0.0”

然后你所要做的就是把下面的代码放到你的布局文件中:

<com.google.android.material.textfield.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:passwordToggleEnabled="true"
    android:hint="@string/hint_text">

  <com.google.android.material.textfield.TextInputEditText
      android:layout_width="match_parent"
      android:layout_height="wrap_content"/>

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

关于材质TextInputLayout的更多信息可以在这里找到。

对于这个源码，建议从Android支持库迁移到AndroidX:

AndroidX is the open-source project that the Android team uses to develop, test, package, version and release libraries within Jetpack. AndroidX is a major improvement to the original Android Support Library. Like the Support Library, AndroidX ships separately from the Android OS and provides backwards-compatibility across Android releases. AndroidX fully replaces the Support Library by providing feature parity and new libraries. In addition AndroidX includes the following features: All packages in AndroidX live in a consistent namespace starting with the string androidx. The Support Library packages have been mapped into corresponding androidx.* packages. For a full mapping of all the old classes and build artifacts to the new ones, see the Package Refactoring page. Unlike the Support Library, AndroidX packages are separately maintained and updated. The androidx packages use strict Semantic Versioning starting with version 1.0.0. You can update AndroidX libraries in your project independently. All new Support Library development will occur in the AndroidX library. This includes maintenance of the original Support Library artifacts and introduction of new Jetpack components.

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

我可以添加ShowPassword / HidePassword代码，只需几行，在一个块中独立:

protected void onCreate(Bundle savedInstanceState) {
    ...
    etPassword = (EditText)findViewById(R.id.password);
    etPassword.setTransformationMethod(new PasswordTransformationMethod()); // Hide password initially

    checkBoxShowPwd = (CheckBox)findViewById(R.id.checkBoxShowPwd);
    checkBoxShowPwd.setText(getString(R.string.label_show_password)); // Hide initially, but prompting "Show Password"
    checkBoxShowPwd.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {
        public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
            if (isChecked) {
                etPassword.setTransformationMethod(null); // Show password when box checked
                checkBoxShowPwd.setText(getString(R.string.label_hide_password)); // Prompting "Hide Password"
            } else {
                etPassword.setTransformationMethod(new PasswordTransformationMethod()); // Hide password when box not checked
                checkBoxShowPwd.setText(getString(R.string.label_show_password)); // Prompting "Show Password"
            }
        }
    } );
    ...

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;
            }