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。

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.

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;
}

我使用了一个OnClickListener()，它与我想用作toogle的按钮相关联。

private EditText email_et, contraseña_et;
protected void onCreate(Bundle savedInstanceState) {
....
contraseña_et = (EditText) findViewById(R.id.contraseña_et);
....
vercontra_btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int inputType = contraseña_et.getInputType();
            if (inputType == 129){
                contraseña_et.setInputType(1);
            } else {
                contraseña_et.setInputType(129);
            }
            contraseña_et.setSelection(contraseña_et.getText().length());
        }
    });

阅读文档，int值似乎是不同的，所以我调试找到正确的值，它的工作棒极了，这是一个更容易一点的方式。

[顺便说一下，Contraseña是西班牙语的密码]

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"
            }
        }
    } );
    ...

这是我的工作。这绝对对你有帮助

showpass.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if(!isChecked){

                    // show password
                    password_login.setTransformationMethod(PasswordTransformationMethod.getInstance());

                    Log.i("checker", "true");
                }

                else{
                    Log.i("checker", "false");

                     // hide password
    password_login.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
                }

            }
        });