Filename is empty in SaveDialogue

Question

I am trying to save a xml file generated in the code using Savedialogue.

I have given the following code in my click button command.

 

var saveDialog = new Microsoft.Win32.SaveFileDialog()

{

Filter = "Loan Parameters(*.xml)|"

};

if (saveDialog.ShowDialog() == false)

{

return;

}

 

// XML Serialization and Binary Encoding

byte[] buffer = LoanDataHelper.SerializeModel(loanParameterValueConfig);

if (buffer != null)

{

LoanDataHelper.WriteStreamToFile(buffer, saveDialog.FileName, LoanDataHelper.FileFormat.Normal);

}

 

I am using mvvm model  .On running I am getting exception as filename is not getting the value that I am passing in the savedialogue window.It is always empty string. 

 

I could not figure out what i am missing here.

Please help.

Thanks in advance