I have gridview built dynamically at run-time bind to datatable, and button to save gridview data placed outside gridview
1- Create GridView
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
CreateGrid();
}
}
void CreateGrid()
{
int nTransID = Convert.ToInt32(Session["trans_id"]);
//
string strSQL = #"EXEC [dbo].[sp_GetTransaction] " + nTransID;
DataTable dtData = clsGlobal.GetDataTable(strSQL);
//
if (ViewState["dtTransDetail"] == null) ViewState.Add("dtTransDetail", dtData);
else ViewState["dtTransDetail"] = dtData;
//
foreach (DataColumn dc in dtData.Columns)
{
if (dc.ColumnName.Contains("!;"))
{
TemplateField tField = new TemplateField();
tField.ItemTemplate = new AddTemplateToGridView(ListItemType.Item, dc.ColumnName);
//\\ --- template contain textbox
tField.HeaderText = dc.ColumnName;
GridView1.Columns.Add(tField);
}
}
}
This is my template class:
public class AddTemplateToGridView : ITemplate
{
ListItemType _type;
string _colName;
public AddTemplateToGridView(ListItemType type, string colname)
{
_type = type;
_colName = colname;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_type)
{
case ListItemType.Item:
TextBox text = new TextBox();
text.ID = "txtAmount";
text.DataBinding += new EventHandler(txt_DataBinding);
container.Controls.Add(text);
break;
}
}
void txt_DataBinding(object sender, EventArgs e)
{
TextBox textBox = (TextBox)sender;
GridViewRow container = (GridViewRow)textBox.NamingContainer;
object dataValue = DataBinder.Eval(container.DataItem, _colName);
if (dataValue != DBNull.Value)
{
textBox.Text = dataValue.ToString();
}
}
}
So i have a gridview with textboxe's all open to edit at once
The problem is, when i click on Save button "which is outside gridview" all textboxe's gone
protected void btnSave_Command(object sender, CommandEventArgs e)
{
for (int nRow = 0; nRow < GridView1.Rows.Count; nRow++)
{
for (int nCol = 0; nCol < GridView1.Columns.Count; nCol++)
{
if (GridView1.Rows[nRow].Cells[nCol].Controls.Count == 0) continue;
//\\ --- Controls.Count always = 0
//\\ --- However each cell contain textbox
//\\ --- textbox disappear after save button clicked
TextBox txt = (TextBox)GridView1.Rows[nRow].Cells[nCol].Controls[0];
}
}
}
It looks like you are not creating the GridView after a postback, and the Save button is causing a postback. You need to dynamically create the GridView on each page load. Also, I have found this documentation on the ASP.NET page lifecycle helpful on numerous occasions.
In the documentation, you will see the slightly unintuitive reason why your code isn't working as you would like - btnSave_Command is not run until after a postback and Page_Load.
I use an gridview empty datasource for bulk insert, how would I prepopulate for instance Column A with the value of a drop down box? So far I have below, but its not working
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
TextBox tb = (TextBox)e.Row.FindControl("YourTextBoxID");
if(tb != null)
{
tb.Text = DropDownList1.SelectedItem.Text;
}
}
}
I don't understand what you mean with empty DataSource. I assume that you actully mean a DataSource which is populated automatically with a default value.
You could use a DataTable:
var tbl = new DataTable();
tbl.Columns.Add("ColumnA");
var defText = DropDownList1.SelectedItem.Text;
for(int i = 0; i < 1000; i++)
{
tbl.Rows.Add(defText);
}
GridView1.DataSource = tbl;
GridView1.DataBind();
I am having a gridview in asp.net and now I want the cell value by the column name but not by the cell index.
How would be it possible by retrieving the cell value by the cell column name
GridView does not act as column names, as that's it's datasource property to know those things.
If you still need to know the index given a column name, then you can create a helper method to do this as the gridview Header normally contains this information.
int GetColumnIndexByName(GridViewRow row, string columnName)
{
int columnIndex = 0;
foreach (DataControlFieldCell cell in row.Cells)
{
if (cell.ContainingField is BoundField)
if (((BoundField)cell.ContainingField).DataField.Equals(columnName))
break;
columnIndex++; // keep adding 1 while we don't have the correct name
}
return columnIndex;
}
remember that the code above will use a BoundField... then use it like:
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int index = GetColumnIndexByName(e.Row, "myDataField");
string columnValue = e.Row.Cells[index].Text;
}
}
I would strongly suggest that you use the TemplateField to have your own controls, then it's easier to grab those controls like:
<asp:GridView ID="gv" runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblName" runat="server" Text='<%# Eval("Name") %>' />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
and then use
string columnValue = ((Label)e.Row.FindControl("lblName")).Text;
Although its a long time but this relatively small piece of code seems easy to read and get:
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
int index;
string cellContent;
foreach (TableCell tc in ((GridView)sender).HeaderRow.Cells)
{
if( tc.Text.Equals("yourColumnName") )
{
index = ((GridView)sender).HeaderRow.Cells.GetCellIndex(tc);
cellContent = ((GridView)sender).SelectedRow.Cells[index].Text;
break;
}
}
}
You can use the DataRowView to get the column index.
void OnRequestsGridRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
var data = e.Row.DataItem as DataRowView;
// replace request name with a link
if (data.DataView.Table.Columns["Request Name"] != null)
{
// get the request name
string title = data["Request Name"].ToString();
// get the column index
int idx = data.Row.Table.Columns["Request Name"].Ordinal;
// ...
e.Row.Cells[idx].Controls.Clear();
e.Row.Cells[idx].Controls.Add(link);
}
}
}
For Lambda lovers
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
var boundFields = e.Row.Cells.Cast<DataControlFieldCell>()
.Select(cell => cell.ContainingField).Cast<BoundField>().ToList();
int idx = boundFields.IndexOf(
boundFields.FirstOrDefault(f => f.DataField == "ColName"));
e.Row.Cells[idx].Text = modification;
}
}
Based on something found on Code Project
Once the data table is declared based on the grid's data source, lookup the column index by column name from the columns collection. At this point, use the index as needed to obtain information from or to format the cell.
protected void gridMyGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DataTable dt = (DataTable)((GridView)sender).DataSource;
int colIndex = dt.Columns["MyColumnName"].Ordinal;
e.Row.Cells[colIndex].BackColor = Color.FromName("#ffeb9c");
}
}
Header Row cells sometimes will not work. This will just return the column Index. It will help in a lot of different ways. I know this is not the answer he is requesting. But this will help for a lot people.
public static int GetColumnIndexByHeaderText(GridView gridView, string columnName)
{
for (int i = 0; i < gridView.Columns.Count ; i++)
{
if (gridView.Columns[i].HeaderText.ToUpper() == columnName.ToUpper() )
{
return i;
}
}
return -1;
}
A little bug with indexcolumn in alexander's answer:
We need to take care of "not found" column:
int GetColumnIndexByName(GridViewRow row, string columnName)
{
int columnIndex = 0;
int foundIndex=-1;
foreach (DataControlFieldCell cell in row.Cells)
{
if (cell.ContainingField is BoundField)
{
if (((BoundField)cell.ContainingField).DataField.Equals(columnName))
{
foundIndex=columnIndex;
break;
}
}
columnIndex++; // keep adding 1 while we don't have the correct name
}
return foundIndex;
}
and
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int index = GetColumnIndexByName(e.Row, "myDataField");
if( index>0)
{
string columnValue = e.Row.Cells[index].Text;
}
}
}
We can get it done in one line of code. No need to loop through anything or call other methods.
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
string cellValue = e.Row.Cells[e.Row.Cells.GetCellIndex(e.Row.Cells.Cast<DataControlFieldCell>().FirstOrDefault(cell => cell.ContainingField.HeaderText == "columnName"))].Text;
}
}
//get the value of a gridview
public string getUpdatingGridviewValue(GridView gridviewEntry, string fieldEntry)
{//start getGridviewValue
//scan gridview for cell value
string result = Convert.ToString(functionsOther.getCurrentTime());
for(int i = 0; i < gridviewEntry.HeaderRow.Cells.Count; i++)
{//start i for
if(gridviewEntry.HeaderRow.Cells[i].Text == fieldEntry)
{//start check field match
result = gridviewEntry.Rows[rowUpdateIndex].Cells[i].Text;
break;
}//end check field match
}//end i for
//return
return result;
}//end getGridviewValue
It is possible to use the data field name, if not the title so easily, which solved the problem for me. For ASP.NET & VB:
e.g. For a string:
Dim Encoding = e.Row.DataItem("Encoding").ToString().Trim()
e.g. For an integer:
Dim MsgParts = Convert.ToInt32(e.Row.DataItem("CalculatedMessageParts").ToString())
protected void CheckedRecords(object sender, EventArgs e)
{
string email = string.Empty;
foreach (GridViewRow gridrows in GridView1.Rows)
{
CheckBox chkbox = (CheckBox)gridrows.FindControl("ChkRecords");
if (chkbox != null & chkbox.Checked)
{
int columnIndex = 0;
foreach (DataControlFieldCell cell in gridrows.Cells)
{
if (cell.ContainingField is BoundField)
if (((BoundField)cell.ContainingField).DataField.Equals("UserEmail"))
break;
columnIndex++;
}
email += gridrows.Cells[columnIndex].Text + ',';
}
}
Label1.Text = "email:" + email;
}
protected void gvResults_PreRender(object sender, EventArgs e)
{
var gridView = (GridView)sender;
gridView.GetColumnByName("YourDataBoundDataField").Visible = true;
}
Extension:
public static DataControlField GetColumnByName(this GridView gridView, string columnName)
{
int columnIndex = -1;
for (int i = 0; i < gridView.Columns.Count; i++)
{
if (gridView.Columns[i].HeaderText.Trim().Equals(columnName, StringComparison.OrdinalIgnoreCase))
{
columnIndex = i;
break;
}
}
if (columnIndex == -1)
{
throw new ArgumentOutOfRangeException("GridViewRow does not have the column with name: " + columnName);
}
return gridView.Columns[columnIndex];
}
The primary reason this would be difficult is because gridview cells do not have accessible cell names (ugh).
In order to work around this handicap you can make an extension method (mine is in VB.NET, but #Дмитрийh seems to have a similar solution in C#).
To work around this ensure the HeaderText of the gridview cells have the same value as the cellnames and grab the values via that HeaderText name.
Here is extension methods you would need for strings and integers in a VB.NET code snippet that I made
Public Shared Function GetStringByCellName(pGridViewRow As GridViewRow, pCellName As String) As String
For Each myCell As DataControlFieldCell In pGridViewRow.Cells
If myCell.ContainingField.ToString() = pCellName Then
Return myCell.Text
End If
Next
Return Nothing
End Function
And the difference for integers being a parse/cast
Public Shared Function GetIntegerByCellName(pGridViewRow As GridViewRow, pCellName As String) As Integer
For Each myCell As DataControlFieldCell In pGridViewRow.Cells
If myCell.ContainingField.ToString() = pCellName Then
Return Integer.Parse(myCell.Text)
End If
Next
Return Nothing
End Function
And calling the functions would look like this if it were in a class.
Dim columnNamesStringValue As String = ExtensionMethodsClassName.GetStringByCellName(pGridViewRow, "stringOfColumnName")
Dim columnNamesIntegerValue As Integer = ExtensionMethodsClassName.GetIntegerByCellName(pGridViewRow, "stringOfColumnName")
have in mind that you may not always get a value, and instead may get Nothing
Before you (perhaps try to put the value in your database), ensure it is not nothing first by checking that it is not nothing. If you wanted to insert into the database, however, it may be better to return a System.DBNull instead of Nothing from the extension methods I provided.
(DO NOT CHECK AND INSERT THE OTHER NULLS or Nothing AS DBNull'S. DIFFERENT TYPES OF NULL'S AND NOTHINGS ARE NOT EQUAL)
If (columnNamesStringValue IsNot Nothing)
This must be something that a lot of people have done. Basically, it's a custom GridView (i.e. inherited control) with the ability to update all rows at once. I've tried putting the "update all" button in various places (footer, pager, outside the grid), but it looks neatest (to me) when the button is in an extra row as the last row of the GridView.
NB: The pager row is not a suitable place for this button because this custom control could be used in a situation where paging is false. Similarly, the normal footer may be required for some other purpose (e.g. totals).
Here's my code for putting the button in the correct place (with apologies for the terse variables etc.):
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
//Add an extra row to the table...
if (_updateAllEnabled)
{
GridViewRow r = base.CreateRow(-1, -1, DataControlRowType.Footer, DataControlRowState.Normal);
Button btn = new Button();
TableCell c = new TableCell();
btn.ID = "UpdateAllButton"; // tried with and without this line
btn.Text = "Update All";
btn.Click += new EventHandler(UpdateAll);
r.Cells.Add(c);
c.Controls.Add(btn);
Table t = this.Controls[0] as Table;
c.ColumnSpan = this.Columns.Count;
t.Rows.Add(r);
}
}
This gives the appearance that I want, but the click event (UpdateAll) does not fire.
I assume that the stuff is being added too late in the life cycle (PreRender), but where else can I do this to ensure that the row is at the end of the GridView? I also thought that there might be trouble identifying the button, so I tried setting the ID. In any case, the ID in the generated HTML looks OK (consistent with "working" buttons in the pager row.
Is there a way for me to achieve this or am I attempting the impossible?
The best place to create your footer-controls is RowCreated since that's early enough in the lifecycle and also ensures that their recreated on every postback:
Footer approach:
protected void Grid_RowCreated(Object sender, GridViewRowEventArgs e) {
if(e.Row.RowType == DataControlRowType.Footer) {
Button btn = new Button();
TableCell c = new TableCell();
btn.ID = "UpdateAllButton";
btn.Text = "Update All";
btn.Click += new EventHandler(UpdateAll);
var firstCell=e.Row.Cells[0];
firstCell.ColumnSpan =e.Row.Cells.Count;
firstCell.Controls.Add(btn);
while(e.Row.Cells.Count > 1)e.Row.Cells.RemoveAt(e.Row.Cells.Count-1);
}
}
Of course you have to set ShowFooter to true:
<asp:GridView ID="GridView1"
ShowFooter="true"
OnRowCreated="Grid_RowCreated"
runat="server"
</asp:GridView>
Pager approach:
In my opinion this is the purpose of the FooterRow. But if you really want to ensure that your Button is in the very last row of a GridView(even below Pager as commented), i would try my next approach.
Here I'm using the pager for your costom control(s) by adding another TableRow to the PagerTable which inherits from Table.
protected void Grid_RowCreated(Object sender, GridViewRowEventArgs e) {
switch(e.Row.RowType){
case DataControlRowType.Pager:
Button btnUpdate = new Button();
btnUpdate.ID = "UpdateButton";
btnUpdate.Text = "Update";
btnUpdate.Click += new EventHandler(UpdateAll);
var tblPager = (Table)e.Row.Cells[ 0 ].Controls[ 0 ];
var row = new TableRow();
var cell = new TableCell();
cell.ColumnSpan = tblPager.Rows[ 0 ].Cells.Count;
cell.Controls.Add(btnUpdate);
row.Cells.Add(cell);
tblPager.Rows.Add(row);
break;
}
}
To ensure that the pager is visible even if only one page is shown(note that the real pager is invisible if PageSize==1):
protected void Grid_PreRender(object sender, EventArgs e){
GridView gv = (GridView)sender;
GridViewRow gvr = (GridViewRow)gv.BottomPagerRow;
if(gvr != null) {
gvr.Visible = true;
var tblPager = (Table)gvr.Cells[ 0 ].Controls[ 0 ];
//hide real pager if unnecessary
tblPager.Rows[ 0 ].Visible = GridView1.PageCount > 1;
}
}
Of course now you have to set AllowPaging=true:
<asp:GridView ID="GridView1"
AllowPaging="true"
PagerSettings-Mode="NumericFirstLast"
OnRowCreated="Grid_RowCreated"
OnPreRender="Grid_PreRender"
OnPageIndexChanging="Grid_PageChanging"
runat="server">
</asp:GridView>
Final approach(working for a custom GridView and all PagerPositions):
public PagerPosition OriginalPagerPosition{
get { return (PagerPosition)ViewState[ "OriginalPagerPosition" ]; }
set { ViewState[ "OriginalPagerPosition" ] = value; }
}
protected void Page_Load(object sender, EventArgs e){
if(!IsPostBack) OriginalPagerPosition = GridView1.PagerSettings.Position;
GridView1.PagerSettings.Position = PagerPosition.TopAndBottom;
GridView1.AllowPaging = true;
// databinding stuff ...
}
Keep the RowCreated the same as above in Pager approach.
Visibility of top/bottom pagers will be controlled in PreRender according to the OriginalPagerPosition property. Both pagers are created even with PagerPosition=TOP, the bottom pager is required for your additional control(s):
protected void Grid_PreRender(object sender, EventArgs e)
{
GridView gv = (GridView)sender;
GridViewRow tpr = (GridViewRow)gv.TopPagerRow;
GridViewRow bpr = (GridViewRow)gv.BottomPagerRow;
tpr.Visible = gv.PageCount > 1 && (OriginalPagerPosition == PagerPosition.Top || OriginalPagerPosition == PagerPosition.TopAndBottom);
bpr.Visible = true;
var tblBottomPager = (Table)bpr.Cells[ 0 ].Controls[ 0 ];
tblBottomPager.Rows[ 0 ].Visible = gv.PageCount > 1 && (OriginalPagerPosition == PagerPosition.Bottom || OriginalPagerPosition == PagerPosition.TopAndBottom);
var tblTopPager = (Table)tpr.Cells[ 0 ].Controls[ 0 ];
tblTopPager.Rows[1].Visible = false;
}
Note: if you are extending the GridView control, you have to replace all occurences of GridView1(my test-grid) with this.
It would be easy to add an extra row into the grid. But the difficulty in your requirement is that the GridView's RowCollection should not contain this row since that would be error-prone. It should also be the very last row even if paging is enabled. This is (afaik) not possible.
Hence i've chosen to extend the pager with this functionality.
I'll add this as separate answer since my other is already too detailed and describes two different ways(footer,pager) to add controls to a GridView without extending it.
This approach extends a GridView as in your own requirement and is similar to my other pager-approach. But it's cleaner and only adds the additional row to the BottomPager. It woks also for every setting(AllowPaging=false,Pager-Position: Top,Bottom,BottomTop):
[DefaultProperty("EnableUpdateAll")]
[ToolboxData("<{0}:UpdateGridView runat=server></{0}:UpdateGridView>")]
public class UpdateGridView : GridView
{
[Bindable(true)]
[Category("Appearance")]
[DefaultValue("true")]
[Localizable(true)]
public bool EnableUpdateAll
{
get
{
Object val = ViewState["EnableUpdateAll"];
return ((val == null) ? true : (bool)val);
}
set
{
ViewState["EnableUpdateAll"] = value;
}
}
private bool OriginalAllowPaging
{
get
{
Object val = ViewState["OriginalAllowPaging"];
return (bool)val;
}
set
{
ViewState["OriginalAllowPaging"] = value;
}
}
private PagerPosition OriginalPagerPosition
{
get
{
Object val = ViewState["OriginalPagerPosition"];
return (PagerPosition)val;
}
set
{
ViewState["OriginalPagerPosition"] = value;
}
}
protected override void OnInit(System.EventArgs e)
{
if (ViewState["OriginalPagerPosition"] == null)
OriginalPagerPosition = base.PagerSettings.Position;
if(OriginalPagerPosition != PagerPosition.Bottom)
PagerSettings.Position=PagerPosition.TopAndBottom;
if (ViewState["OriginalAllowPaging"] == null)
OriginalAllowPaging = base.AllowPaging;
base.AllowPaging = true;
}
protected override void OnRowCreated(GridViewRowEventArgs e)
{
switch (e.Row.RowType)
{
case DataControlRowType.Pager:
//check if we are in BottomPager
if (this.Rows.Count != 0 && this.EnableUpdateAll)
{
Button btnUpdate = new Button();
btnUpdate.ID = "BtnUpdate";
btnUpdate.Text = "Update";
btnUpdate.Click += new EventHandler(UpdateAll);
var tblPager = (Table)e.Row.Cells[0].Controls[0];
var row = new TableRow();
var cell = new TableCell();
cell.ColumnSpan = tblPager.Rows[0].Cells.Count;
cell.Controls.Add(btnUpdate);
row.Cells.Add(cell);
tblPager.Rows.Add(row);
}
break;
}
}
protected override void OnPreRender(EventArgs e)
{
bool bottomPagerVisible =
OriginalAllowPaging &&
PageCount > 1 &&
(OriginalPagerPosition == PagerPosition.Bottom || OriginalPagerPosition == PagerPosition.TopAndBottom);
BottomPagerRow.Visible = bottomPagerVisible || EnableUpdateAll;
var tblBottomPager = (Table)BottomPagerRow.Cells[0].Controls[0];
tblBottomPager.Rows[0].Visible = bottomPagerVisible;
}
private void UpdateAll(Object sender, EventArgs e)
{
// do something...
}
}
I have a data table in dt in c# code and it has column[0] datatype is int.So when ever I reach 7th value in the table I need to convert to hyperlink and add it back to data table.
int x = int.Parse(dt.Rows[7][0].ToString());
dt.Row[7][0] = "" + x + "";
but it is givin me the error that can not accept string value to integer. How to over come this?
Correct me I'm wrong. Add an extra column of string type.
dt.Columns.Add("LinkColumn");
...
dt.Rows[7]["LinkColumn"]=string.Format("<a href='#'>{0}</a>",x);
How are you creating the data table? The column has probably been typed to int, so it can not accept string values.
A better way might be to change the data bound control to show the link
protected override void OnInit(EventArgs e) {
base.OnInit(e);
DataBound += new EventHandler(GridView1_DataBound);
}
void GridView_RowDataBound(object sender, GridViewRowEventArgs e) {
GridView gridview = (GridView)sender;
if (e.Row.RowType == DataControlRowType.DataRow) {
for (int i = 0; i < gridview.Columns.Count; i++) {
DataControlField obj1 = gridview.Columns[i];
if (obj1.GetType() == typeof(BoundField)) {
BoundField field = (BoundField)obj1;
string datafield = field.DataField;
object value = DataBinder.Eval(e.Row.DataItem, datafield);
Literal c = new Literal();
c.Text = "";
e.Row.Cells[i].Controls.Add(c);
}
}
}
}