Add a textbox to a wpf canvas in a position chosen by the user (C#) -

i add functionality wpf c# app allows user following:

when press button, textbox created in corner of canvas, when you're done typing , press button again, next click set new position of textbox on canvas.

i tried writing code doesn't solid, plus error explained below:

int = 0;  system.windows.point currentpoint = new system.windows.point();  private void button1_click(object sender, routedeventargs e, system.windows.input.mouseeventargs e2) {     = + 1;     if (i == 1)     {         textblock tb = new textblock();         tb.text = "successfull";         tb.background = brushes.white;         tb.name = "textb";         mycanvas.children.add(tb);          canvas.setleft(tb, 10);         canvas.settop(tb, 10);     }      if (i == 2)     {         thread.sleep(500);         while (e2.leftbutton != mousebuttonstate.pressed)         {              thread.sleep(50);         }         if (e2.leftbutton == mousebuttonstate.pressed)         {             currentpoint = e2.getposition(this);             canvas.setleft(tb, currentpoint.x);             canvas.settop(tb, currentpoint.y);         }         i=0;     }  } 

however declared textbox (tb) inside of "if" statement, when try modify position, considered unknown canvas.setleft(tb, currentpoint.x); . if declare outside, textbox created if button isn't pressed. ideas?

also if have solution looks less ugly, feel free share!

a potential (but honest quick & dirty one), solution following mainwindow.xaml:

<window x:class="canvastextbox.mainwindow"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     title="mainwindow" height="350" width="525"> <grid>     <grid.rowdefinitions>         <rowdefinition height="auto" />         <rowdefinition height="*" />     </grid.rowdefinitions>     <button grid.row="0" click="onbuttonclick" >click me</button>     <canvas grid.row="1" background="lightskyblue"              x:name="positioningcanvas"             previewmouseup="onpreviewmouseup">         <textbox x:name="textbox" visibility="collapsed" minwidth="80" />     </canvas> </grid> 

with mainwindow.cs this:

    public mainwindow()     {         initializecomponent();     }      private bool istextediting;      private void onbuttonclick(object sender, routedeventargs e)     {         if (!istextediting)         {             textbox.visibility = visibility.visible;             istextediting = true;         }         else         {             istextediting = false;         }     }      private void onpreviewmouseup(object sender, mousebuttoneventargs e)     {         // long textbox.visibility collapsed , user in 'textediting' after         // first click, don't handle clicks in canvas         if (!istextediting && textbox.visibility == visibility.visible)         {             point clickpoint = e.getposition(positioningcanvas);             canvas.settop(textbox, clickpoint.y);             canvas.setleft(textbox, clickpoint.x);         }     }