buscador

[mjesus20]

hola tengo el siguiente codigo para el buscar datos en mi grid pero al momento de ejecutarlo no me produce nada alguien me podria indicar por que

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim item As String
TextBox1.Text = "item"
Dim dbConnection As System.Data.IDbConnection = New System.Data.SqlClient.SqlConnection(connectionStri ng)
Dim dbCommand As System.Data.IDbCommand = New System.Data.SqlClient.SqlCommand()
queryString = "select * from inventario where [Inventario].[Item]=@item "
dbCommand.CommandText = queryString
dbCommand.Connection = dbConnection
Dim dataadapter As System.Data.IDbDataAdapter = New System.Data.SqlClient.SqlDataAdapter()
dataadapter.SelectCommand = dbCommand
Dim dbParam_item As System.Data.IDataParameter = New System.Data.SqlClient.SqlParameter()
dbParam_item.ParameterName = "@Item"
dbParam_item.Value = TextBox1.Text
dbParam_item.DbType = System.Data.DbType.String
dbCommand.Parameters.Add(dbParam_item)
Dim dataset As System.Data.DataSet = New System.Data.DataSet()
dataadapter.Fill(dataset)
DataGrid1.DataSource = dataset
DataGrid1.DataBind()
End Sub