I can't seem to get this right, even after looking at a few examples.
I've got this code, which happily re-sorts my gridview in an Ascending order:
// gridViewSorting and ConvertSortDirectionToSql are both necessary to ensure the gridview can sort when their column headers are
// clicked. You must remember to add (AllowSorting="True" OnSorting="gridViewSorting") to the gridview tag on the ASP side
protected void gridViewSorting(object sender, GridViewSortEventArgs e)
{
DataTable dataTable = GVInactive.DataSource as DataTable;
if (dataTable != null)
{
DataView dataView = new DataView(dataTable);
string SQL = "[" + e.SortExpression + "] " + ConvertSortDirectionToSql(e.SortDirection);
dataView.Sort = SQL;
GVInactive.DataSource = dataView.ToTable();
GVInactive.DataBind();
}
}
private string ConvertSortDirectionToSql(SortDirection sortDirection)
{
string newSortDirection = String.Empty;
switch (sortDirection)
{
case SortDirection.Ascending:
newSortDirection = "DESC";
break;
case SortDirection.Descending:
newSortDirection = "ASC";
break;
}
return newSortDirection;
}
However, the second time I click on the header it's supposed to reverse the previous sorting order. It never does. Every time I click the header of a column, it hits the case SortDirection.Ascending: line and sets newSortDirection = "DESC". The data is sorted in descending order, yet when I click the header again it resolves SortDirection to Ascending.
Any ideas?
We use a ViewState variable to store the latest Sort Direction. When the grid is sorted we compare the Sort Criteria and Sort Direction of the grid with the ViewState variables which stores last sort expression. If the columns are equal then check the direction of the previous sort and sort in the opposite direction.
Example:
private string SortCriteria
{
get
{
if (ViewState["sortCriteria"] == null)
{
ViewState["sortCriteria"] = "";
}
return ViewState["sortCriteria"].ToString();
}
set
{
ViewState["sortCriteria"] = value;
}
}
private string SortDirection
{
get
{
if (ViewState["sortDirection"] == null)
{
ViewState["sortDirection"] = "";
}
return ViewState["sortDirection"].ToString();
}
set
{
ViewState["sortDirection"] = value;
}
}
protected void gvData_Sorting(object sender, GridViewSortEventArgs e)
{
gvData.EditIndex = -1;
if (SortCriteria == e.SortExpression)
{
if (SortDirection == string.Empty || SortDirection == "DESC") { SortDirection = "ASC"; }
else { SortDirection = "DESC"; }
}
else
{
SortCriteria = e.SortExpression;
SortDirection = "ASC";
}
BindGrid();
}
private void BindGrid()
{
DataTable dt = new [However you get dataset from database];
DataView dv = new DataView(dt);
dv.Sort = string.Format("{0} {1}", SortCriteria, SortDirection).Trim();
gvData.DataSource = dv;
gvData.DataBind();
}
For the record, I replaced the code used in my question with this, and it worked perfectly:
// gridViewSorting and ConvertSortDirectionToSql are both necessary to ensure the gridview can sort when their column headers are
// clicked. You must remember to add (AllowSorting="True" OnSorting="gridViewSorting") to the gridview tag on the ASP side
protected void gridViewSorting(object sender, GridViewSortEventArgs e)
{
DataTable dataTable = GVInactive.DataSource as DataTable;
string sortExpression = e.SortExpression;
string direction = string.Empty;
if (dataTable != null)
{
DataView dataView = new DataView(dataTable);
if (SortDirection == SortDirection.Ascending)
{
SortDirection = SortDirection.Descending;
direction = " DESC";
}
else
{
SortDirection = SortDirection.Ascending;
direction = " ASC";
}
DataTable table = GVInactive.DataSource as DataTable;
table.DefaultView.Sort = sortExpression + direction;
GVInactive.DataSource = table;
GVInactive.DataBind();
}
}
public SortDirection SortDirection
{
get
{
if (ViewState["SortDirection"] == null)
{
ViewState["SortDirection"] = SortDirection.Ascending;
}
return (SortDirection)ViewState["SortDirection"];
}
set
{
ViewState["SortDirection"] = value;
}
}
I can probably remove a few lines (not sure I even need the DataView anymore), but it works perfectly as is. Just remember to add these pieces to the ASP side in the GridView tag:
AllowSorting="True" OnSorting="gridViewSorting"
and then change your gridview's name where appropriate.
Related
I work in C-sharp on ASP NET 4.
I need to add a sorting function to a column in a GridView. I've set the AllowSorting-property on the GridView to true and added sort expressions to the column.
Unfortunately, the sorting isn't working in the GridView.
Below is my code-behind-file for the column that should be able to sort, but I get the error
CS1502: The best overloaded method match for 'System.Data.DataView.DataView(System.Data.DataTable)' has some invalid arguments
on this line:
DataView sortedView = new DataView(BindData());
Code behind:
string sortingDirection;
public SortDirection dir
{
get
{
if (ViewState["dirState"] == null)
{
ViewState["dirState"] = SortDirection.Ascending;
}
return (SortDirection)ViewState["dirState"];
}
set
{
ViewState["dirState"] = value;
}
}
public string SortField
{
get
{
return (string)ViewState["SortField"] ?? "Name";
}
set
{
ViewState["SortField"] = value;
}
}
protected void gvProducts_Sorting(object sender, GridViewSortEventArgs e)
{
sortingDirection = string.Empty;
if (dir == SortDirection.Ascending)
{
dir = SortDirection.Descending;
sortingDirection = "Desc";
}
else
{
dir = SortDirection.Ascending;
sortingDirection = "Asc";
}
DataView sortedView = new DataView(RetrieveProducts());
sortedView.Sort = e.SortExpression + " " + sortingDirection;
SortField = e.SortExpression;
gvProducts.DataSource = sortedView;
gvProducts.DataBind();
}
protected void gvProducts_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
if (dir == SortDirection.Ascending)
{
sortingDirection = "Asc";
}
else
{
sortingDirection = "Desc";
}
DataView sortedView = new DataView(RetrieveProducts());
sortedView.Sort = SortField + " " + sortingDirection;
gvProducts.DataSource = sortedView;
gvProducts.PageIndex = e.NewPageIndex;
gvProducts.DataBind();
}
private void BindData()
{
gvProducts.DataSource = RetrieveProducts();
gvProducts.DataBind();
}
private DataSet RetrieveProducts()
{
DataSet dsProducts = new DataSet();
string sql = " ... ";
using (OdbcConnection cn =
new OdbcConnection(ConfigurationManager.ConnectionStrings["ConnMySQL"].ConnectionString))
{
cn.Open();
using (OdbcCommand cmd = new OdbcCommand(sql, cn))
{
........
}
}
return dsProducts;
}
Edit #1
DataView sortedView = new DataView(dsProducts.Tables[0]);
Edit # 2
I have added in aspx page:
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
But If clicked in Column Name I have this new error:
System.IndexOutOfRangeException: Cannot find table 0.
on this line:
Line 100: DataView sortedView = new DataView(dsProducts.Tables[0]);
The DataView class has only three constructors, in which one is default constructor DataView(), second one takes a DataTable as an argument DataView(DataTable), the other one takes four arguments DataView(DataTable, String, String, DataViewRowState).
The DataView constructor expects arguments of any one of these types, but your code has argument of some other type. That's the error.
Your BindData method should return a DataTable object,
//This function should return a Datatable
private void BindData()
{
gvProducts.DataSource = RetrieveProducts();
gvProducts.DataBind();
}
which you can pass into your DataView here.
DataView sortedView = new DataView(BindData());
For your second edit,
System.IndexOutOfRangeException: Cannot find table 0.
on this line:
Line 100: DataView sortedView = new DataView(dsProducts.Tables[0]);
I guess the dataset is empty, the error clearly states that there isn't any table in the dataset at position 0. So check whether your dataset has tables or not. Might be your sql request didn't get any table to fill in the dataset.
Else you might have created a new instance of the dataset.
when I click on the line update the gridview sort of disappears and returns to its initial state. what can be?
Below transcribe my code:
private string GetSortDirection(string column)
{
// By default, set the sort direction to ascending.
string sortDirection = "ASC";
// Retrieve the last column that was sorted.
string sortExpression = ViewState["SortExpression"] as string;
if (sortExpression != null)
{
// Check if the same column is being sorted.
// Otherwise, the default value can be returned.
if (sortExpression == column)
{
string lastDirection = ViewState["SortDirection"] as string;
if ((lastDirection != null) && (lastDirection == "ASC"))
{
sortDirection = "DESC";
}
}
}
// Save new values in ViewState.
ViewState["SortDirection"] = sortDirection;
ViewState["SortExpression"] = column;
return sortDirection;
}
protected void GridViewLayoutProduto_Sorting(object sender, GridViewSortEventArgs e)
{
//Retrieve the table from the session object.
DataTable dt = Session["TaskTable"] as DataTable;
if (dt != null)
{
//Sort the data.
dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression);
Session["TaskTable"] = dt;
GridViewLayoutProduto.DataSource = Session["TaskTable"];
GridViewLayoutProduto.DataBind();
}
}
protected void GridViewLayoutProduto_RowEditing(object sender, GridViewEditEventArgs e)
{
GridViewLayoutProduto.EditIndex = e.NewEditIndex;
//CheckBox alt = GridViewLayoutProduto.Rows[e.NewEditIndex].FindControl("CheckBox1") as CheckBox;
//alt.Enabled = false;
BindData();
}
protected void GridViewLayoutProduto_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridViewLayoutProduto.PageIndex = e.NewPageIndex;
GridViewLayoutProduto.DataBind();
}
protected void GridViewLayoutProduto_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridViewLayoutProduto.EditIndex = -1;
BindData();
}
private void BindData()
{
GridViewLayoutProduto.DataSource = Session["TaskTable"];
GridViewLayoutProduto.DataBind();
}
in the session data the datatable to stored will not be organized, how can I store in a session with the datatble sort performed.
Try Putting this line after Sort of GridView
Session["TaskTable"] = ((DataView)gvProgramlar.DataSource).ToTable();
Hope this helps you!
I have a GridView with sorting enabled. For a single page result both the ascending and descending works fine. But when there are multiple pages, descending alone works well. the asceding also works but when i click on the next pages, it becomes unsorted again.
I don't know whether the problem is because of the sort direction or paging. Kindly Help.
Below are the codes:
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
GridView grid = sender as GridView;
//Retrieve the table from the session object.
DataTable dt = Session["List"] as DataTable;
if (dt != null)
{
//Sort the data.
dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression);
grid.DataSource = Session["List"];
grid.DataBind();
}
}
private string GetSortDirection(string column)
{
string sortDirection = "ASC";
string sortExpression = ViewState["SortExpression"] as string;
if (sortExpression != null)
{
if (sortExpression == column)
{
string lastDirection = ViewState["SortDirection"] as string;
if ((lastDirection != null) && (lastDirection == "ASC"))
{
sortDirection = "DESC";
}
}
}
// Save new values in ViewState.
ViewState["SortDirection"] = sortDirection;
ViewState["SortExpression"] = column;
return sortDirection;
}
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
GridView1.DataSource = bindGridView();
GridView1.DataBind();
}
You can use a session variable to store the latest Sort Expression and when you sort the grid next time compare the sort expression of the grid with the Session variable which stores last sort expression. If the columns are equal then check the direction of the previous sort and sort in the opposite direction.
DataTable sourceTable = GridAttendence.DataSource as DataTable;
DataView view = new DataView(sourceTable);
string[] sortData = Session["sortExpression"].ToString().Trim().Split(' ');
if (e.SortExpression == sortData[0])
{
if (sortData[1] == "ASC")
{
view.Sort = e.SortExpression + " " + "DESC";
this.ViewState["sortExpression"] = e.SortExpression + " " + "DESC";
}
else
{
view.Sort = e.SortExpression + " " + "ASC";
this.ViewState["sortExpression"] = e.SortExpression + " " + "ASC";
}
}
else
{
view.Sort = e.SortExpression + " " + "ASC";
this.ViewState["sortExpression"] = e.SortExpression + " " + "ASC";
}
After so many research, I found the correct answer for my own question. This would probably help someone in future. Add the following code to the bindGridView()
if (ViewState["sortExpr"] != null)
{
dv = new DataView(ds.Tables[0]);
dv.Sort = (string)ViewState["sortExpr"];
}
else
dv = ds.Tables[0].DefaultView;
and
#region Sorting
protected void Gridview1_Sort(object sender, GridViewSortEventArgs e)
{
ViewState["sortExpr"] = e.SortExpression + " " + GetSortDirection(e.SortExpression);
Gridview1.DataSource = bindGridView();
Gridview1.DataBind();
}
private string GetSortDirection(string column)
{
// By default, set the sort direction to ascending.
string sortDirection = "ASC";
// Retrieve the last column that was sorted.
string sortExpression = ViewState["SortExpression"] as string;
if (sortExpression != null)
{
// Check if the same column is being sorted.
// Otherwise, the default value can be returned.
if (sortExpression == column)
{
string lastDirection = ViewState["SortDirection"] as string;
if ((lastDirection != null) && (lastDirection == "ASC"))
{
sortDirection = "DESC";
}
}
}
// Save new values in ViewState.
ViewState["SortDirection"] = sortDirection;
ViewState["SortExpression"] = column;
return sortDirection;
}
#endregion
I have developed an asp.net application that has a Gridview control. I want it to sort when I click on the Gridview header text in asp.net. Entity framework is used to bind the gridview.
protected void grdmortgagesaver_Sorting(object sender, GridViewSortEventArgs e)
{
string sortExpression = e.SortExpression;
if (GridViewSortDirection == SortDirection.Ascending)
{
GridViewSortDirection = SortDirection.Descending;
SortGridView(sortExpression, DESCENDING);
}
else
{
GridViewSortDirection = SortDirection.Ascending;
SortGridView(sortExpression, ASCENDING);
}
}
private void SortGridView(string sortExpression, string direction)
{
// You can cache the DataTable for improving performance
var databind = from i in mortgageentites.Clients orderby i.LastName select i;
if (databind.Count() > 0)
{
grdmortgagesaver.DataSource = databind.ToList();
grdmortgagesaver.DataBind();
DataTable dt = clients;
if (dt != null)
{
// DataTable dt = ds.Tables[0];
DataView dv = new DataView(dt);
dv.Sort = sortExpression + direction;
grdmortgagesaver.DataSource = dv;
grdmortgagesaver.DataBind();
}
}
}
If you are using a standard ASP.NET System.Web.UI.WebControls.GridView, you can simply "Enable Sorting", in the properties pane by setting "AllowSorting" to true or via the "pop-out" on the top right of the control by checking "Enable Sorting"
add AllowSorting="true" in your gridview control and
protected void grd_Sorting(object sender, GridViewSortEventArgs e)
{
if (e.SortExpression == hdfSortExp.Value)
{
if (hdfUpDown.Value == "1")
hdfUpDown.Value = "0";
else
hdfUpDown.Value = "1";
}
else //New Column clicked so the default sort direction will be incorporated
hdfUpDown.Value = "0";
hdfSortExp.Value = e.SortExpression; //Update the sort column
BindGrid(hdfSortExp.Value, this.CBool(hdfUpDown.Value));
}
in your c# code
public void BindGrid(string sortBy, bool inAsc)
{
grd.DataSource = WManager.GetAdminTags(txtSearch.Text.Trim(), sortBy, inAsc);
grd.DataBind();
}
First in your Page in the GridView Declaration Tag add the property AllowSorting="true" and in the Gridview_SortCommand try the Following code as guidence
try {
if (SortType == false) {
SortView.Sort = e.SortExpression + " ASC";
//dviewGeneral.Sort = e.SortExpression & " ASC"
Session.Item("SortOrder") = SortView.Sort.ToString;
SortType = true;
} else {
SortView.Sort = e.SortExpression + " DESC";
Session.Item("SortOrder") = SortView.Sort.ToString;
//dviewGeneral.Sort = e.SortExpression & " DESC"
SortType = false;
}
CMSgrid.SelectedIndex = -1;
CMSgrid.CurrentPageIndex = 0;
SortBind();
} catch (Exception ex) {
UserMsgBox(ex.ToString());
}
I have a gridview where I bind a datasource, and I had to add sorting for this gridview; I added the code below to that, but it didn't work well.
private string ConvertSortDirectionToSql(SortDirection sortDireciton)
{
string m_SortDirection = String.Empty;
switch (sortDireciton)
{
case SortDirection.Ascending:
m_SortDirection = "ASC";
break;
case SortDirection.Descending:
m_SortDirection = "DESC";
break;
}
return m_SortDirection;
}
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable m_DataTable = GridView1.DataSource as DataTable;
if (m_DataTable != null)
{
DataView m_DataView = new DataView(m_DataTable);
m_DataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);
GridView1.DataSource = m_DataView;
GridView1.DataBind();
}
}
You can use this, as I had the same problem, and I solved it like this.
public string SortingExpression
{
get
{
if (this.ViewState["SortExpression"] == null)
return "";
else
return (string)this.ViewState["SortExpression"];
}
set
{
this.ViewState["SortExpression"] = value;
}
}
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable m_DataTable = GridView1.DataSource as DataTable;
if (m_DataTable != null)
{
DataView m_DataView = new DataView(m_DataTable);
SortingExpression = e.SortExpression + " " + (SortingExpression.Contains("ASC") ? "DESC" : "ASC");
m_DataView.Sort =SortingExpression;
GridView1.DataSource = m_DataView;
GridView1.DataBind();
}
}
Maybe this could help if your sortdirection is always ascending.
Try this out. This method worked for me.
dt is the datatable containing the values.
protected void onSorting_Gridview1(object sender, GridViewSortEventArgs e)
{
string _sortDirection = dir.ToString();
if(_sortDirection.Equals("Ascending"))
{
_sortDirection = "ASC";
dir = SortDirection.Descending;
}
else
{
_sortDirection="DESC";
dir = SortDirection.Ascending;
}
if (dt != null)
{
//Sort the data.
dt.DefaultView.Sort = e.SortExpression + " " + _sortDirection;
gridView1.DataSource = dt;
gridView1.DataBind();
}
}
public SortDirection dir
{
get
{
if (ViewState["DIR"] == null)
{
ViewState["DIR"] = SortDirection.Ascending;
}
return (SortDirection)ViewState["DIR"];
}
set
{
ViewState["DIR"] = value;
}
}