Got it, let's break down what's going wrong and how to fix your problem cleanly:

The core issue here is that setMultiChoiceItems() is designed to create a built-in multi-select list for AlertDialogs—this method overrides or adds onto your custom layout, which is why you're seeing an extra Checkbox and your own isn't responding. Instead, you need to directly interact with the Checkbox in your custom XML layout after inflating it.

Step 1: Verify Your Custom Layout XML #

First, make sure your layout (let's call it dialog_password_input.xml) is set up correctly with your EditText and Checkbox. Example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/dialog_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Enter Your Password"
        android:textSize="18sp"
        android:textStyle="bold"/>

    <EditText
        android:id="@+id/et_password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:inputType="textPassword"
        android:layout_marginTop="8dp"/>

    <CheckBox
        android:id="@+id/cb_show_password"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Password"
        android:layout_marginTop="8dp"/>

</LinearLayout>

Step 2: Inflate Layout and Bind Checkbox Event in Code #

Instead of using setMultiChoiceItems(), inflate your custom layout, attach it to the AlertDialog, then manually find your Checkbox and set its listener. Here's how to do it in Java:

// Inflate your custom layout
LayoutInflater inflater = getLayoutInflater();
View dialogView = inflater.inflate(R.layout.dialog_password_input, null);

// Get references to your views
EditText passwordEt = dialogView.findViewById(R.id.et_password);
CheckBox showPasswordCb = dialogView.findViewById(R.id.cb_show_password);

// Set up the Checkbox listener to toggle password visibility
showPasswordCb.setOnCheckedChangeListener((buttonView, isChecked) -> {
    int inputType = isChecked ? 
        InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD :
        InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD;
    passwordEt.setInputType(inputType);
    // Move cursor to end of text after changing input type
    passwordEt.setSelection(passwordEt.getText().length());
});

// Build the AlertDialog
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setView(dialogView)
       .setPositiveButton("Confirm", (dialog, which) -> {
           // Get password when user confirms
           String password = passwordEt.getText().toString().trim();
           // Do something with the password
       })
       .setNegativeButton("Cancel", (dialog, which) -> dialog.dismiss());

AlertDialog dialog = builder.create();
dialog.show();

If you're using Kotlin, the code looks like this:

// Inflate layout
val dialogView = layoutInflater.inflate(R.layout.dialog_password_input, null)
val passwordEt = dialogView.findViewById<EditText>(R.id.et_password)
val showPasswordCb = dialogView.findViewById<CheckBox>(R.id.cb_show_password)

// Checkbox listener
showPasswordCb.setOnCheckedChangeListener { _, isChecked ->
    val inputType = if (isChecked) {
        InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD
    } else {
        InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_PASSWORD
    }
    passwordEt.inputType = inputType
    passwordEt.setSelection(passwordEt.text.length)
}

// Build dialog
AlertDialog.Builder(this)
    .setView(dialogView)
    .setPositiveButton("Confirm") { _, _ ->
        val password = passwordEt.text.toString().trim()
        // Handle password
    }
    .setNegativeButton("Cancel") { dialog, _ -> dialog.dismiss() }
    .create()
    .show()

Key Notes: #

• Never use setMultiChoiceItems() with a custom layout if you want to keep your own Checkbox—this method is for creating a standard multi-select list, not interacting with custom views.
• Always inflate your layout first, then get view references before building the dialog. If you try to find views after calling dialog.show(), you might run into null reference issues.
• Toggling the input type and resetting the cursor position ensures the user's text stays visible and the cursor doesn't jump to the start.

内容的提问来源于stack exchange，提问作者Brian Reinhold