Custom Actions using C# from WIX

[balajipkn]

Hi,

I am trying to pass parameters from WIX to C# code, but I am not able to do it properly. To code that I have written on WIX side is:
<Property Id="teststring">
<![CDATA[Hello world]]>
</Property>
<CustomAction Id="testing" Return="check" BinaryKey="test" DllEntry="hello"/>
<Binary Id="test" src="test.dll" />
<CustomAction Id="testing.setproperty" Return="check" Property="testing" Value="[teststring]" />

<InstallExecuteSequence>
<Custom Action="testing.setproperty" After="InstallFiles" />
<Custom Action="testing" After="testing.setproperty" />
</InstallExecuteSequence>

The code I have written in C# and compiled as a DLL is :

using System;
using System.Text;
using System.Runtime.InteropServices;

namespace testing
{
public class test{
public static int hello(IntPtr handle)
{
int i;
int ptrcnt = 256;
//System.Windows.Forms.MessageBox.Show( String.Format( "Hello World {0}",handle) );
StringBuilder sb = new StringBuilder(ptrcnt);
i = MsiGetProperty(handle,"CustomActionData",sb,ref ptrcnt);
System.Windows.Forms.MessageBox.Show( String.Format( "{0}",sb ) ;

return 0;
}
[DllImport("msi.dll", CharSet=CharSet.Unicode)]
static extern int MsiGetProperty(IntPtr hInstall, string szName, [Out] StringBuilder szValueBuf, ref int pchValueBuf);


}
}

But I am not able to pass the property value to C#. Can anyone please let me know if I am missing anything.

Thank you,
regards
balaji.