有没有一种方法可以使TextView的所有字母都小写？

<TextView
    android:id="@+id/myTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World" />

TextView textView = findViewById(R.id.myTextView);
textView.setTransformationMethod(new LowerCaseTransformationMethod());

import android.text.method.TransformationMethod;
import android.view.View;

public class LowerCaseTransformationMethod implements TransformationMethod {
    @Override
    public CharSequence getTransformation(CharSequence source, View view) {
        return source.toString().toLowerCase();
    }

    @Override
    public void onFocusChanged(View view, CharSequence sourceText, boolean focused, int direction, Rect previouslyFocusedRect) {
        // 不需要实现
    }
}