你可以使用下面的代码显示/隐藏密码:

XML代码:

<EditText
        android:id="@+id/etPassword"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="21dp"
        android:layout_marginTop="14dp"
        android:ems="10"
        android:inputType="textPassword" >
        <requestFocus />
    </EditText>
    <CheckBox
        android:id="@+id/cbShowPwd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/etPassword"
        android:layout_below="@+id/etPassword"
        android:text="@string/show_pwd" />

JAVA代码:

EditText mEtPwd;
CheckBox mCbShowPwd;


mEtPwd = (EditText) findViewById(R.id.etPassword);
mCbShowPwd = (CheckBox) findViewById(R.id.cbShowPwd);

mCbShowPwd.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        // checkbox status is changed from uncheck to checked.
        if (!isChecked) {
            // show password
            mEtPwd.setTransformationMethod(PasswordTransformationMethod.getInstance());
        } else {
            // hide password
            mEtPwd.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
        }
    }
});

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

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");
    }


}

TextInputLayout的更新代码:

   <androidx.cardview.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toTopOf="@+id/lg_forget_password"
    app:layout_constraintTop_toBottomOf="@+id/lg_name"
    app:cardElevation="@dimen/dp20"
    android:layout_marginStart="@dimen/dp20"
    app:cardCornerRadius="@dimen/dp10"
    android:layout_marginEnd="@dimen/dp20"
    android:id="@+id/textField">

    <com.google.android.material.textfield.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="@android:color/transparent"
        app:boxStrokeWidth="0dp"
        app:boxStrokeWidthFocused="0dp"
        app:endIconMode="password_toggle"
        app:hintEnabled="false"
      >

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/lg_password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/input_bg"
            android:drawableStart="@drawable/ic_baseline_lock_24"
            android:drawablePadding="@dimen/dp10"
            android:fontFamily="@font/roboto_flex"
            android:hint="@string/password"
            android:inputType="textPassword"
            android:padding="@dimen/dp15"
            android:singleLine="true" />

    </com.google.android.material.textfield.TextInputLayout>
</androidx.cardview.widget.CardView>

结果:

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.

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"
            }
        }
    } );
    ...