Canvas doesn't draw text?

I want to display some text on the screen when the user clicks buttonwith canvasin android studio. I've been watching a lot of posts and videos on how to do this. The problem is, when I try their code, when I click the button, nothing is displayed. Does anyone know what I am doing wrong?

Here is my Javaclass:

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button drawCanvas = findViewById(R.id.draw_canvas_button);

    drawCanvas.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            Paint paint = new Paint();
            Canvas canvas = new Canvas();
            paint.setColor(Color.BLACK);
            paint.setStyle(Paint.Style.FILL);
            paint.setTextSize(20f);
            canvas.drawText("My Text", 10f, 15f, paint);

        }
    });
}
}