publicclassDrawViewextendsView{publicfloatcurrentX=40;publicfloatcurrentY=50;publicDrawView(Contextcontext){super(context);}//重写ondraw,通过canvas绘画protectedvoidonDraw(Canvascanvas){Paintpaint=newPaint();paint.setColor(Color.RED);canvas.drawCircle(currentX,currentY,25,paint);}

<?xmlversion="1.0"encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical"android:background="#99FFCC"android:id="@+id/root"></LinearLayout>

publicclassMainActivityextendsActivity{@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);LinearLayoutroot=(LinearLayout)findViewById(R.id.root);finalDrawViewdrawView=newDrawView(this);WindowManagerwm=this.getWindowManager();intwidth=wm.getDefaultDisplay().getWidth();intheight=wm.getDefaultDisplay().getHeight();Toast.makeText(this,"widthis"+width+"height"+height,Toast.LENGTH_LONG).show();drawView.setMinimumHeight(300);drawView.setMinimumHeight(500);drawView.setOnTouchListener(newView.OnTouchListener(){@OverridepublicbooleanonTouch(Viewv,MotionEventevent){drawView.currentX=event.getX();drawView.currentY=event.getY();drawView.invalidate();returntrue;}});root.addView(drawView);}}