Please create a new WebPage to test this.
When you click on the Save Button alert will show with the data contained in the ViewState property.
HTML
<div>
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td>
<asp:Button Text="Add" OnClick="Add" runat="server" />
</td>
<td>
<asp:Button Text="Edit" OnClick="Edit" runat="server" />
</td>
</tr>
</table>
<br />
<asp:Button Text="Save" OnClick="Save" runat="server" />
</div>
C#
public bool Message
{
get
{
return Convert.ToBoolean(ViewState["Message"]);
}
set
{
ViewState["Message"] = value;
}
}
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
this.Message = false;
}
}
protected void Add(object sender, EventArgs e)
{
this.Message = true;
}
protected void Edit(object sender, EventArgs e)
{
this.Message = false;
}
protected void Save(object sender, EventArgs e)
{
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('value contained in the ViewState is " + this.Message + "' )", true);
}