C# 2008 Programmer's Reference

 <Canvas>
  <Canvas x:Name='SigPad' Width='404' Height='152'
   Canvas.Left='8' Canvas.Top='9' Background='#FFF4F60C'>
   <Rectangle Width='404' Height='152' Fill='#FFF1F8DB'
    Stroke='#FF000000' StrokeThickness='3'/>
  </Canvas>
  <Canvas>
   <Canvas x:Name='btnSave' Width='97' Height='26'
    Canvas.Left='315' Canvas.Top='168'>
    <Rectangle Width='96' Height = '25'
     Stroke='#FF000000' Fill='#FFE6EBFF'
     RadiusX='3' RadiusY='3' StrokeThickness='3'/>
    <TextBlock Width='34' Height='20'
     TextWrapping='Wrap' Canvas.Left='32'
     Canvas.Top='1' Text ='Save'/>
   </Canvas>
   <Canvas x:Name='btnLoad' Width='97' Height='26'
    Canvas.Left='214' Canvas.Top='168'>
    <Rectangle Width='96' Height='25'
     Stroke='#FF000000' Fill='#FFE6EBFF'
     RadiusX='3' RadiusY='3' StrokeThickness='3'/>
    <TextBlock Width='37' Height='20' TextWrapping='Wrap'
     Canvas.Left='30' Canvas.Top='1' Text='Load'/>
   </Canvas>
   <Canvas x:Name='btnClear' Width='97' Height='26'
    Canvas.Left='113' Canvas.Top='168'>
    <Rectangle Width='96' Height='25' Stroke='#FF000000'
     Fill='#FFE6EBFF' RadiusX='3' RadiusY='3'
     StrokeThickness='3'/>
    <TextBlock Width='37' Height='20' TextWrapping='Wrap'
     Canvas.Left='30' Canvas.Top='1' Text='Clear'/>
   </Canvas>
   <TextBlock Width='404' Height='20' Text='[Status]'
    TextWrapping='Wrap' Canvas.Left='8' Canvas.Top='198'
    OpacityMask='#FF000000' x:Name='txtStatus'/>
  </Canvas>
 </Canvas>
</UserControl>

Page.xaml should now look like Figure 19-71.

Figure 19-71

In Page.xaml.cs, import the following namespaces:

using System.IO.IsolatedStorage;
using System.IO;

Add the following lines to the Page() constructor:

public Page() {
 InitializeComponent();
 //---wire up the event handlers---
 SigPad.MouseLeftButtonDown += new
  MouseButtonEventHandler(SigPad_MouseLeftButtonDown);
 SigPad.MouseLeftButtonUp += new
  MouseButtonEventHandler(SigPad_MouseLeftButtonUp);
 SigPad.MouseMove += new
  MouseEventHandler(SigPad_MouseMove);
 //---wire up the event handlers---
 btnSave.MouseLeftButtonDown += new
  MouseButtonEventHandler (btnSave_MouseLeftButtonDown);
 btnLoad.MouseLeftButtonDown += new
  MouseButtonEventHandler (btnLoad_MouseLeftButtonDown);
 btnClear.MouseLeftButtonDown += new
  MouseButtonEventHandler (btnClear_MouseLeftButtonDown);
}

Define the GetSignatureLines() function so that the coordinates of the signature can be converted from a List object to a string:

//---returns the signature as a series of lines---
private string GetSignatureLines() {
 System.Text.StringBuilder sb = new
  System.Text.StringBuilder();
 //---for each line---
 for (int i = 0; i <= _lines.Count - 1; i++) {
  //---for each point---
  foreach (Point pt in _lines[i]) {
   sb.Append(pt.X + ',' + pt.Y + '|');
  }
  sb.Append('
');
 }
 return sb.ToString();
}

Code the MouseLeftButtonDown event handler for the Save button so that the signature can be saved to isolated storage:

//---Save button---
void btnSave_MouseLeftButtonDown(
 object sender, MouseButtonEventArgs e) {
 //---save into isolated storage---
 IsolatedStorageFile isoStore =
  IsolatedStorageFile.GetUserStoreForApplication();
 IsolatedStorageFileStream isoStream =
  new IsolatedStorageFileStream('IsoStoreFile.txt',
  FileMode.Create, isoStore);
 StreamWriter writer = new StreamWriter(isoStream);
 //---writes the lines to file---
 writer.Write(GetSignatureLines());