Android Multimedia Programming--drawing board

 PackageCom.example.huahuaban;ImportJava.io.File;Importjava.io.FileNotFoundException;ImportJava.io.FileOutputStream;ImportAndroid.net.Uri;ImportAndroid.os.Bundle;Importandroid.os.Environment;Importandroid.app.Activity;Importandroid.content.Intent;ImportAndroid.graphics.Bitmap;ImportAndroid.graphics.Bitmap.CompressFormat;Importandroid.graphics.BitmapFactory;ImportAndroid.graphics.Canvas;ImportAndroid.graphics.Color;ImportAndroid.graphics.Matrix;ImportAndroid.graphics.Paint;ImportAndroid.graphics.PorterDuff.Mode;ImportAndroid.graphics.PorterDuffXfermode;Importandroid.view.MotionEvent;ImportAndroid.view.View;ImportAndroid.view.View.OnClickListener;ImportAndroid.view.View.OnTouchListener;ImportAndroid.widget.ImageView; Public classMainactivityextendsActivityImplementsonclicklistener{PrivateImageView img;    Bitmap bitmapcopy;    Paint paint;    Bitmap bitmapsrc; floatStartX =0; floatStarty = 0; PrivateCanvas Canvas; PrivateMatrix MT; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.activity_main); IMG=(ImageView) Findviewbyid (r.id.img); Findviewbyid (r.id.red). Setonclicklistener ( This); Findviewbyid (R.id.gereen). Setonclicklistener ( This); Findviewbyid (R.id.blue). Setonclicklistener ( This); Findviewbyid (R.id.shua). Setonclicklistener ( This); Findviewbyid (R.id.qingkong). Setonclicklistener ( This); Findviewbyid (R.id.save). Setonclicklistener ( This); BITMAPSRC=Bitmapfactory.decoderesource (Getresources (), r.drawable.bg); Bitmapcopy=Bitmap.createbitmap (Bitmapsrc.getwidth (), Bitmapsrc.getheight (), Bitmapsrc.getconfig ()); //BrushesPaint =NewPaint (); Canvas=NewCanvas (bitmapcopy); Mt=NewMatrix ();            Canvas.drawbitmap (BITMAPSRC, MT, paint); Img.setontouchlistener (NewOntouchlistener () {@Override Public BooleanOnTouch (View arg0, motionevent event) {intAction =event.getaction (); Switch(action) { CaseMotionevent.action_down://set the start coordinate of a segmentStartX =Event.getx (); Starty=event.gety ();  Break;  CaseMotionevent.action_move://End coordinates                    floatx =Event.getx (); floaty =event.gety ();                    Canvas.drawline (StartX, Starty, x, y, paint);                    Img.setimagebitmap (bitmapcopy); //assigns the value of the end coordinate to the start coordinateStartX =x; Starty=y;  Break;  Casemotionevent.action_up: Break; }                return true;    }        }); } @Override Public voidOnClick (View v) {Switch(V.getid ()) { CaseR.id.red:paint.setcolor (color.red);  Break;  CaseR.id.gereen:paint.setcolor (Color.green);  Break;  CaseR.id.blue:paint.setcolor (Color.Blue);  Break;  CaseR.id.qingkong:paint.setxfermode (NewPorterduffxfermode (mode.clear));             Canvas.drawbitmap (BITMAPSRC, MT, paint); Paint.setxfermode (NewPorterduffxfermode (MODE.SRC));            Img.invalidate ();  Break;  CaseR.id.shua:paint.setstrokewidth (3.5f);  Break;  Caser.id.save:file File=NewFile ("Sdcard/ok1.png"); FileOutputStream out=NULL; Try{ out=Newfileoutputstream (file); } Catch(FileNotFoundException e) {//TODO auto-generated Catch blockE.printstacktrace (); }            //Save the file, the parameters are format, compression quality 0-100, output streamBitmapcopy.compress (compressformat.png, 100, out); //send a broadcast that updates a multimedia databaseIntent Intent =NewIntent ();            Intent.setaction (intent.action_media_mounted);            Intent.setdata (Uri.fromfile (Environment.getexternalstoragedirectory ()));            Sendbroadcast (Intent);  Break; }            }}

<LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:tools= "Http://schemas.android.com/tools"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent"Tools:context=". Mainactivity "android:orientation= "vertical">    <ImageViewAndroid:id= "@+id/img"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"android:src= "@drawable/bg"/>    <LinearLayoutAndroid:layout_width= "Match_parent"Android:layout_height= "Wrap_content"android:orientation= "Horizontal"        >        <ButtonAndroid:id= "@+id/red"Android:background= "#FF0000"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"                        />        <ButtonAndroid:id= "@+id/gereen"Android:background= "#00FF00"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"                        />        <ButtonAndroid:id= "@+id/blue"Android:background= "#3366FF"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"                        />        <ButtonAndroid:id= "@+id/shua"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Bold"            />        <ButtonAndroid:id= "@+id/qingkong"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Empty"            />    </LinearLayout>         <ButtonAndroid:id= "@+id/save"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Save"            /></LinearLayout>

Android Multimedia Programming--drawing board