网格视图过滤数据

Question

I am interested in getting all the data a user sees in a grid view, after he applies some filters. For example, the original grid's datasource contains 10 records, but the user apply a filter after which only 5 are still being displayed, I want to take those 5 and put them in a list. How can this be accomplished?

Answer 1

Assuming your grid is bound a some collection, then on postback, you can grab the datasource of the gridview, apply your filters, and save it to a new collection.

Something like:

var datasource = yourGridView.DataSource as List<someType>;
var filteredResults = datasource.Where( ... ); // apply your filters inside the Where

Obviously, replace the example variable names / types with what you're using in your code.

Answer 2

Heres a nice little example of a kind of built in way to filter grid views:

protected void btnSearch(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection("MyConn");
    SqlCommand cmd = new SqlCommand();
    SqlDataAdapter sda = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();

    cmd.Connection = con;
    cmd.CommandText = "SELECT * FROM CustomerTable WHERE NumberOfCustomer = @NumberOfCustomer";
    cmd.Parameters.AddWithValue("NumberOfCustomer", TextBox1.Text);

    try
    {
        con.Open();
        sda.Fill(dt);
    }
    catch (Exception ex)
    {
        Response.Write(ex.Message);
    }
    finally
    {
        con.Close();
    }

    GridView1.DataSource = dt;
    GridView1.DataBind();
}

And then to bind the datasource to a list:

protected void bindToList(object sender, EventArgs e)
{
    var datasource = GridView1.DataSource as List<Customers>;

    if ( !IsPostBack )
    {
        DropDownList ddl = new DropDownList();
        ddl.DataTextField = "Name";
        ddl.DataValueField = "Id";
        ddl.DataSource = datasource;
        ddl.DataBind();

        ddl.SelectedValue = list.Find( o => o.Selected == true ).Id.ToString();
    }
}