windows phone 8 - How to show canvas on tapping on the image -

i have defined datatemplate in app.xaml have there image , in custom page have canvas how can show canvas on tapping on image? here datatemplate in app.xaml

<datatemplate x:key="flightinfodatatemplate">             <grid horizontalalignment="stretch" width="420">                 <grid.columndefinitions>                     <columndefinition width="auto"/>                 </grid.columndefinitions>                <!-- here controls, not necessary now-->                     <image tag="{binding id}" source="/images/bel_icon_2.png" width="20" height="20" visibility="{binding path=status, converter={staticresource statustovisibilityconverter}}" />                 <!--***********-->             </grid>         </datatemplate> 

here canvas defined in mainpage.xaml

<canvas x:name="addreminderdialog" horizontalalignment="center"  height="280" width="260"                 verticalalignment="center" background="transparent" margin="110,178,110,238" visibility="collapsed">             <textblock foreground="yellow" text="Напомнить" horizontalalignment="center" canvas.left="78" canvas.top="28" />             <button name="btn1hourbef" borderthickness="0" background="black" content="За час" width="260" fontsize="15" height="60" margin="0,70,0,0"/>             <button name="btn30minbef" borderthickness="0" background="black" content="За 30 минут" width="260" fontsize="15" height="60" margin="0,130,0,0"/>             <button name="btn10minbef" borderthickness="0" background="black" content="По прилету/вылету" width="260" fontsize="15" height="60" margin="0,190,0,0"/>         </canvas> 

how can make visible on tapping on image?

edit - canvas meant used notification, , preferably reusable on several pages:

per comments, became clear intention of canvas provide notification message. suitable concept of dismissible popup. there system.windows.controls.primitives.popup class in framework.

example: in app.xaml:

<datatemplate x:key="flightinfodatatemplate"> ... <image tag="{binding id}" source="/images/bel_icon_2.png" width="20" height="20" visibility="{binding path=status, converter={staticresource statustovisibilityconverter}}" tap="image_tap"/> ... </datatemplate>  <controltemplate x:key="addreminderdialog">     <canvas horizontalalignment="center"  height="280" width="260" verticalalignment="center" background="whitesmoke" margin="110,178,110,238">         <textblock foreground="black" text="hello" horizontalalignment="center" canvas.left="78" canvas.top="28" />         <button name="btn1hourbef" borderthickness="0" background="black" content="За час" width="260" fontsize="15" height="60" margin="0,70,0,0"/>         <button name="btn30minbef" borderthickness="0" background="black" content="За 30 минут" width="260" fontsize="15" height="60" margin="0,130,0,0"/>         <button name="btn10minbef" borderthickness="0" background="black" content="По прилету/вылету" width="260" fontsize="15" height="60" margin="0,190,0,0"/>     </canvas> </controltemplate> 

in app.xaml.cs:

public partial class app : application {     private popup popup = new popup(); ...  private void image_tap(object sender, system.windows.input.gestureeventargs e) {     var image = sender image;     var modelitem = image.datacontext;      const double width = 200;     const double height = 100;      var content = new contentcontrol(){width = width, height = height, background = new solidcolorbrush(colors.purple)};     content.template = (controltemplate) resources["addreminderdialog"];     content.datacontext = modelitem; // should define bindings in controltemplate.      popup.child = content;     popup.height = height;     popup.width = width;     popup.verticaloffset = application.current.rootvisual.rendersize.height / 2 - height / 2;     popup.horizontaloffset = application.current.rootvisual.rendersize.width / 2 - width / 2;     popup.isopen = true; }