Use of path in Android

Implement a simple drawing tool: (You can draw any in the view, click the Clear button, you can redraw, like I draw you guess)

Custom View Code:

 Public classMySurfaceView2extendsSurfaceviewImplementsSurfaceholder.callback, View.ontouchlistener {PrivatePath MPath =NewPath (); PrivatePaint Mpaint =NewPaint ();  PublicMySurfaceView2 (Context context) {Super(context);    Init (); }     PublicMySurfaceView2 (Context context, AttributeSet attrs) {Super(context, attrs);    Init (); }    Private voidinit () {Setontouchlistener ( This); Getholder (). Addcallback ( This); }     Public voidDraw () {canvas Canvas=Getholder (). Lockcanvas ();        Canvas.drawcolor (Color.White);        Canvas.drawpath (Mpath,mpaint);    Getholder (). Unlockcanvasandpost (canvas); }    //clean up the canvas     Public voidClear () {mpath.reset ();    Draw (); } @Override Public voidsurfacecreated (Surfaceholder surfaceholder) {} @Override Public voidSurfacechanged (Surfaceholder Surfaceholder,intIintI1,intI2)    {Draw (); } @Override Public voidsurfacedestroyed (Surfaceholder surfaceholder) {} @Override Public BooleanOnTouch (view view, Motionevent motionevent) {Switch(Motionevent.getaction ()) { CaseMotionEvent.ACTION_DOWN:mPaint.setStyle (Paint.Style.STROKE);                Mpaint.setcolor (color.red);                Mpath.moveto (Motionevent.getx (), motionevent.gety ());  Break;  CaseMotionevent.action_move://Generate linesMpath.lineto (Motionevent.getx (), motionevent.gety ());                Draw ();  Break; }        return true; }}

To load a custom view in XML:

<?XML version= "1.0" encoding= "Utf-8"?><LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:app= "Http://schemas.android.com/apk/res-auto"android:orientation= "vertical"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent">    <com. Example.lance.test2.MySurfaceView2 Android:id= "@+id/my_surface"Android:layout_width= "Match_parent"Android:layout_height= "Wrap_content"Android:layout_weight= "1"/>    <ButtonAndroid:id= "@+id/btn"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Clear"/></LinearLayout>

In the main activity code:

 Public classMainactivityextendsappcompatactivity {PrivateMySurfaceView2 mMySurfaceView2; PrivateButton Mbutton; @Overrideprotected voidonCreate (@Nullable Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.four); MMySurfaceView2=(MYSURFACEVIEW2) Findviewbyid (r.id.my_surface); Mbutton=(Button) Findviewbyid (R.ID.BTN); Mbutton.setonclicklistener (NewView.onclicklistener () {@Override Public voidOnClick (view view) {mmysurfaceview2.clear ();    }        }); }}

Use of path in Android