Android – surfaceview (width, height) problem

I'm new to Android and I face some problems

I use surfaceview to expand my course. In my class, I can't get the width and height of surfaceview. It's always 0. I try to flick the image on the whole screen, but I can't get its width and height

Any suggestions?

The following is the code of surfaceview in main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <test.MyClass android:id="@+id/SurfaceView01"
        android:layout_width="fill_parent" android:layout_height="fill_parent">
    </test.MyClass>
</LinearLayout>

resolvent:

I tried something similar and posted it on this post Android: UI elements over canvas layer

In addition to the above, you also need it to get height and width

public void onDraw(Canvas canvas)
{
    this.canvas = canvas;

    if (!oneTime)
    {
        oneTime = true;
        screenWidth = getWidth();
        screenHeight = getHeight();
        Bitmap red = BitmapFactory.decodeResource(getResources(), R.drawable.image);
        red = Bitmap.createScaledBitmap(red, screenWidth , screenHeight , true);
    }
}

If you don't want to extract the code in OnDraw, you can try the following code

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int screenHeight = metrics.heightPixels;
int screenWidth = metrics.widthPixels;

But this gives you the width and height of the entire visible area