停用AlertDialog "OK“按钮，直到在AlertDialog视图的EditText上键入文本

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.Button;
import android.widget.EditText;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private AlertDialog alertDialog;
    private EditText editText;
    private Button okButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 创建 AlertDialog
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        editText = new EditText(this);
        builder.setView(editText);
        builder.setPositiveButton("OK", null); // 初始设置为 null，稍后设置监听器
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });

        alertDialog = builder.create();

        // 获取 OK 按钮
        okButton = alertDialog.getButton(DialogInterface.BUTTON_POSITIVE);

        // 设置 TextWatcher 监听器
        editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                okButton.setEnabled(!s.toString().isEmpty());
            }

            @Override
            public void afterTextChanged(Editable s) {}
        });

        // 显示 AlertDialog
        alertDialog.show();
    }
}