Surfaceview examples of Android programming _android

This example describes the Surfaceview usage of Android programming. Share to everyone for your reference, specific as follows:

Related knowledge about Surfaceview:

The main differences between view and Surfaceview :

1. View can only be refreshed in the UI thread, while Surfaceview may be refreshed in child threads

2. Surfaceview can control the refresh frequency

Surfaceview Several important methods :

1. After inheriting Surfaceview, call the Getholder () method to obtain the Msurfaceholder object, which can control the rendering of Surfaceview.

2. Implement this Surfaceholder.callback interface and Msurfaceholder.addcallback (this) to add a callback to perceive the Surfaceview lifecycle

3. When drawing Mcanvas.drawcolor (Color.Black); This method is very important, this method is to clean up the last drawing of things, this method must call to see the effect

The implementation effect is as follows:

The first step: new Xrsurfaceview inheritance Surfaceview

Package com.rong.activity;
Import Android.content.Context;
Import Android.graphics.Canvas;
Import Android.graphics.Color;
Import Android.graphics.Paint;
Import Android.util.AttributeSet;
Import Android.view.SurfaceHolder;
Import Android.view.SurfaceView; /** * Custom Surfaceview * * @author Xu Rong * */public class Xrsurfaceview extends Surfaceview implements Surfaceholder.cal
  Lback, Runnable {//surfaceview wide int surfacewidth;
  Surfaceview High int surfaceheight;
  Surfaceholder object Surfaceholder Msurfaceholder;
  Switch thread's flag bit Boolean isrunning = true;
  Brush Paint mpaint;
  Radius of the circle float radius = 0;
  Whether a circle is larger or smaller is a Boolean status = TRUE;
  The speed of the circle changes int mspeed = 3;
    Public Xrsurfaceview (context, AttributeSet attrs) {Super (context, attrs);
  Initview ();
    private void Initview () {//get Msurfaceholder Msurfaceholder = Getholder ();
  Add callback Msurfaceholder.addcallback (this); @Override public void surfacecreated (SurfaceholderHolder) {isrunning = true;
    Initializes the brush mpaint = new Paint ();
    Mpaint.setantialias (TRUE);
    Mpaint.setcolor (Color.Blue);
  Opens the Draw thread new thread (this). Start ();
    @Override public void surfacechanged (surfaceholder holder, int format, int width, int height) {//Get surface width
    Surfacewidth = width;
  Get the high surfaceheight = height of surface;
  @Override public void surfacedestroyed (Surfaceholder holder) {//close drawing thread isrunning = false;
    @Override public void Run () {Canvas mcanvas = null;
        while (isrunning) {try {//Lock Canva to draw Mcanvas = Msurfaceholder.lockcanvas (null);
        This method is very important, which is equivalent to redrawing (must call or not see the effect) Mcanvas.drawcolor (Color.Black);
        Draw Round Mcanvas.drawcircle ((SURFACEWIDTH/2), (SURFACEHEIGHT/2), radius, mpaint);
          Change radius variable if (status) {radius = radius + mspeed;
          if (Radius >) {status = FALSE; } else{radius = radius-mspeed;
          if (RADIUS < 0) {status = TRUE;
      A catch (Exception e) {e.printstacktrace ());
      finally {//unlock canvas lock Msurfaceholder.unlockcanvasandpost (Mcanvas);

 }
    }
  }
}

Step Two: Create a new layout file Activity_main.xml

<?xml version= "1.0" encoding= "Utf-8"?> <relativelayout xmlns:android=
"http://schemas.android.com/apk" /res/android "
  android:layout_width=" match_parent "
  android:layout_height=" Match_parent "
  android: Background= "#ffffff"
  android:orientation= "vertical" >
  <com.rong.activity.xrsurfaceview
    Android:layout_width= "Match_parent"
    android:layout_height= "match_parent"
    android:layout_centerinparent = "true"
    android:orientation= "vertical"/>
</RelativeLayout>

Run!

More interested readers of Android-related content can view the site's topics: Introduction to Android Development and advanced tutorials, the summary of Android basic components usage, the overview of Android View View techniques, the Android Layout layout skills Summary, and A summary of the usage of Android controls

I hope this article will help you with the Android program.