Update gridview according to checkbox - c#

I have a gridview. It contains checkboxes against all the values. Once I click the checkbox, and press submit, the selected items are inserted into another databse. I want that those selected items shouldn't appear on the current gridview if loaded next time.
For this, what I have planned is that there must be a column in current database to indicate whether the checkbox has been checked or not. The column will be filled with yes/no accordingly. And then display the rows which have only "No" in them.
However, this seems to be lengthy. Is there any other means to achieve this.

Since I believe this is a continuation of your problem from here,
I'll just copy my answer from there.
Sorry if it's not written in c#, I just noticed that tag just now.
You need to include the Primary Key or the column that makes your record Unique in its table. I'll just assume a "ImageID" column.
Place it on a hidden field on your first column.
You'll need it to issue a SQL DELETE or UPDATE statement on those rows after insertion to the destination DB. Although by using the latter, you'll need to have a new column on the table let's say - "TRANSFER_STATUS" tinyint, a switch which you can update 1 or 0.
<Columns>
<asp:TemplateField>
<HeaderTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" AutoPostBack="true"
OnCheckedChanged="CheckUncheckAll"/>
</HeaderTemplate>
<ItemTemplate>
<asp:CheckBox ID ="CheckBox2" runat="server" />
<asp:HiddenField ID="hfImgID" runat="server"
Value=<%# Eval("ImageID") %> />
</ItemTemplate>
</asp:TemplateField>
Code behind:
Dim cbSelect As CheckBox, imgToInsert As Image
Dim ddlStatus As DropDownList, hfImgID As HiddenField
For Each r As GridViewRow In gvDetails.Rows
cbSelect = r.Cells(0).FindControl("CheckBox2")
If cbSelect.Checked Then
hfImgID = r.Cells(0).FindControl("hfImgID")
imgToInsert = r.Cells(1).FindControl("imgPreview")
ddlStatus = r.Cells(2).FindControl("dpdListEstatus")
/*Insert statement goes here...
DELETE or UPDATE statement goes here,
passing the ID of the image from hfImgID.Value*/
End If
Next r
**EDIT**
/*Call your SELECT statement again here to refresh your GridView.
If you used UPDATE, you need to include
your toggle switch in the WHERE clause. TRANSFER_STATUS = 0*/

I don't know what DB you are using, so this is limited, but it will get the value of a cell based on the checkbox--this assumes the chkbox is in the 3rd cell(index 2) and that there is other text in cells 0 and 1 (I don't know what your DGV looks like). it then puts the cell values of the checked rows into a dataset--from there you could dump the dataset into a db of your choice (not sure what you have). In terms of not showing the row on next load, you could change the text of cell 4 (a y/n cell, for example), then update the current database. Next time you load the DGV, include in your call to show only rows with 'y' in column X (are you using SQL?)
'get checked items and add to dataset
Dim i As Integer = 0
For i = 0 To Outdgv.RowCount - 1
If Outdgv.Rows(i).Cells(2).Value = True Then
Dim dsNewRow As DataRow
dsNewRow = dataset.Tables("report").NewRow()
Dim val1 As String = Outdgv.Rows(i).Cells(0).Value
Dim val2 As String = Outdgv.Rows(i).Cells(1).Value
dsNewRow.Item(1) = val1
dsNewRow.Item(2) = val2
dataset.Tables("report").Rows.Add(dsNewRow)
Outdgv.Rows(i).Cells(3).Value = 'n'
End If
Next

From your reply to my comment, it seems a restriction during the current session is suffient. Therefore you could keep track in a session variable.
For example, if your rows have an integer id, you could store a List<int> in session, and add ids to the list each time a checked row is submitted. Then refer to the session variable when refreshing the grid.

I'm not entirely sure what your goal appears to be, but if your trying to hide items that are checked directly from the grid that is possible.
Query: SELECT * FROM [db] WHERE ([Checked] = 0);
So the premise is that if the value is zero, it appears on the grid. If it becomes any other value, it won't appear on the grid.
Grid
<asp:TemplateField HeaderText="Active">
<ItemTemplate>
<asp:CheckBox Id="CustomerCheck" runat="server"
Checked='<%# Eval("Active") %>'
Enabled="false" />
<asp:LinkButton Id="lbCustomerActive" runat="server"
Text="Activate" CommandName="OnActivate"
ToolTip='<%# "Activate or Deactivate Course: " + Eval("CourseId") %>'
OnClick="CustomerCheck_Click" CssClass="Activator" />
</ItemTemplate>
</asp:TemplateField>
You'll now be able to actually write a method for server, called CustomerCheck_Click. That server postback will call your method which can write to the database, once that value in that column is changed the grid will no longer display it.
protected void CustomerCheck_Click(object sender, EventArgs e)
{
// Logic to modify column in database.
}

Related

How to create editable GridView with dynamic controls

How do I create editable gridviews with dynamic controls. The following image gives an idea.
On page load, a gridview will be shown with only a single row other than the header. The row contains two dropdownlist, two textboxes and an image button. Once I enter data in the first row, and then press the image button, a new row with these controls will be created, and so on.
How is this possible?
Gridview by default does not provide a simple way of handling the Insert operations.
You will have to perform several steps to handle this.
First of all each gridview column has to be converted to TemplateColumn(TemplateField). Then in the footer template you have to insert your controls(dropdown, textbox etc.)
<asp:TemplateField HeaderText="Item Category">
<%--Define item template--%>
<FooterTemplate>
<asp:DropDownList ID="dropDownListCategory" runat="server"></asp:DropDownList>
</FooterTemplate>
</asp:TemplateField>
...... similarly other footer templates
You have to add the onclick Event for the ImageButton.
protected void imageButtonInsert_Click(object sender, EventArgs e)
{
//Get the gridview row
GridViewRow row = (sender as Control).NamingContainer as GridViewRow;
DropDownList dropDownListCategory = row.FindControl("dropDownListCategory") as DropDownList;
///Similarly you can access the other controls here
//If you are using SqlDataSource then you can add/assign these values to the insert parameters
//Note that, you need to have insertcommand defined for the sql data source with appropreate parameters
SqlDataSource1.InsertParameters.Add("category", dropDownListCategory.SelectedValue);
//Similarly assign the other parameter values
//Call the insert method of the sql data source.
SqlDataSource1.Insert();
//If you are not using data source approach, here you can insert the data to
// database by calling sql command or other ways
//Rebind the gridview.
GridView1.DataBind();
}
This should work, when you have some rows to display in the gridview.
BIG PROBLEM : EMPTY ROWS
The above approach works when you have at least one row in the gridview. But if you do not have any rows, that is for the first time, the gridview will be empty. If the gridview data source is empty, then it does not display anything, even header,footer, rows etc.
As a initial workaround, first you need to make the header is always visible
ShowHeaderWhenEmpty="true" ShowFooter="true"
This makes sure that you have the headers all the time.
Now footer will not at all display unless and until there is some row in the gridview.
As a work around you can use EmptyDataTemplate of the gridview.
Here you need to add all your controls again, dropdownlist, textboxes etc. Not that you have to use here to make the same layout. You can use the same control ids, so that you dont need to write the codebehind again
<EmptyDataTemplate>
<tr>
<td><asp:DropDownList ID="dropDownListCategory" runat="server"></asp:DropDownList></td>
<td><asp:Button runat="server" CommandName="Insert" ID="buttonInsert" OnClick="imageButtonInsert_Click" Text="Insert" /></td>
<%--Other controls go here--%>
</tr>
</EmptyDataTemplate>
This is now good for both first time and successive load.
The next question you may have is how to bind these dropdowns. For this you need to use the RowCreated event, in which you can access the dropdowns and fill them
protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Footer || e.Row.RowType == DataControlRowType.EmptyDataRow)
{
DropDownList dropDownListCategory = e.Row.FindControl("dropDownListCategory") as DropDownList;
//similarly access the other controls and bind them
}
}
For Doing this use can use Dynamic table at client side. where you can create whole table dynamically and also apply styling that can look like grid view. for Styling use can use JQuery DataTables which provice much more controls.
And also by using JQuery DataTables or JQuery Code you can also add rows dynamically at client side.

How do I use the RowCreated event for GridViews

Problem:
I want to add headers in the middle of a gridview databind. I updated the DataTable to include headers and their correct positions(I've checked during debug, they're there). On the new rows that contain headers, one of the unneeded fields (unneeded as in the header doesn't need that information) has a flag called "Subheader" in it.
Background information:
So my datatable rows hold a server name, and the group the server belongs to. I updated the DataTable so it inserts a new row where the server name is the header text. The server group that this new row belongs to is "Subheader". My datatable holds more information than what my gridview shows. My gridview only needs one column, but has a column with visibility=false; which holds the server group.
What I want to achieve:
So when I bind this datatable to the gridview I want all the non-header rows to be links that point to another location. All the data rows that are headers I want to just leave them as is.
Code:
private void CurrentServers_RowCreated(Object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if(e.Row.Cells[1].Text != "Subheader")
{
e.Row.Cells[0].Text = "<a href='/EventViewer.aspx?m=" + e.Row.Cells[0].Text + "&s=&e=Application&r=25'>" + e.Row.Cells[0].Text + "</a>";
}
}
}
Questions:
This isn't working. e.Row.Cells[1].Text != "Subheader" always returns true. In debugging I check the value of e.Row.Cells[1].Text and somewhere in there it has the information I need.
Is this the correct event I should be handling?
How do I access that data? e.Row.Cells[1].Text and e.Row.Cells[1].ToString() do not return the result that I want, even though when in debugging I can find the value I want in e.Row
I've tried finding exactly how this works but am unable to find answers. If my GridView only has columns for 2 datatable columns, will e.Row.Cells only have the 2 cells that my gridview requires, or does this take place before it breaks apart the datatable (i.e. does it have all the columns that my datatable has)
Depending on how you bind your data and how you get server group, you could do the following:
In the item template where you're showing content of nonheader row, instead of plain text use two placeholders, one will hold label for nonhyperlink text and another will hold hyperlink. You bind both controls to whatever text property you use. And set those placeholders' visibility to Eval("ServerGroup").ToString().ToLowerInvariant().Equals("subheader") and !Eval("ServerGroup").ToString().ToLowerInvariant().Equals("subheader"). That way you won't have to write code to perform control manipulation and get away from using RowDataBound event all together.
Let me know if this doesn't make sense :)
EDIT:
<asp:GridView ID=".." runat="server" ...>
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:PlaceHolder id="phTextContent" runat="server" visible='<%# Eval("ServerGroup").ToString().ToLowerInvariant().Equals("subheader") %>'>
<asp:Label id="lblServerGroup" runat="server" text='<%#Eval("ServerGroup")%>'/>
</asp:PlaceHolder>
<asp:PlaceHolder id="phTextContent" runat="server" visible='<%# !Eval("ServerGroup").ToString().ToLowerInvariant().Equals("subheader") %>'>
<asp:HyperLink id="hlServerGroup" runat="server" Text='<%#Eval("ServerGroup")%>' NavigateUrl='<%#string.Fromat("/MyAction.aspx?param=", Eval("Param"))%>'/>
</asp:PlaceHolder>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

DetailsView binds to columns in database and asp:bound columns resulting in duplicate columns shown?

I have a DetailsView that has a Fields element and some bound columns. The DetailsView is bound to a SqlDataSource. Code on dev and in Environment B is exactly the same, but on dev, I am seeing the columns from the database as well as columns that are bound, so it results in a duplicate columns shown. In Environment B, this is not happening, so I am wondering if it is a data issue, but I am not sure where to start or look?
<asp:DetailsView id="dv" runat="server" DataSourceID="sql" DataKeyNames="Id" OnDataBound="dv_DataBound" OnItemInserted="dv_ItemInserted" OnModeChanged="dv_ModeChanged" HeaderText="Add New" AutoGenerateInsertButton="true">
<Fields>
<asp:BoundField HeaderText="Name" DataField="sName" />
</Fields>
</asp:DetailsView>
The above DetailsView will generate a form that displays label sName with a textbox next to it and another label Name with a TextBox next to it, but the exact same code in Environment B only generates the label Name with a TextBox next to it. This has me thinking it is a data issue, but I can't pinpoint where to start looking. The SqlDataSource.SelectCommand is just a stored proc that is similar to:
SELECT * FROM TABLE_1
Does the DetailsView has something like AutoGenerateColums in gridview?

Adding new Columns to GridView with a new DataSource

I have a gridview that is loaded from a DataSet, in which most of the fields are generated through templates.
One of them is an Image that changes according to the value that is returned from the dataset.
Here is an example:
<asp:TemplateField HeaderText="Attention">
<ItemTemplate>
<asp:Image ID="alertFlag" runat="server" ImageUrl='<%# Eval("alertFlag").ToString().Equals("True") ? "~/Images/Warning-32.png" : "" %>' />
</ItemTemplate>
</asp:TemplateField>
Now I have a dropdown list, in which, depending on what is chosen, a new request to the database is made, and new columns are added, but the previous ones must stay.
Should I create a new GridView or how should I add new the new columns, keep them hidden, and then show them when the proper event is fired. this includes loading new data from the database and binding to the gridview. And how would I add the condition above programatically?
Thanks.
I would say that you will use the same gridview and have column with visible set to true or false. I will suggest that you have a property in the code behind such as ShowColumnX which will return true or false based on the dropdown value. In the aspx, you will then bind the visible property to that value such as Visible="<%= ShowColumnX %>"
If your existing column is setup to bind value correctly to a field of your data source, then you dont have to do anything different then what you have already done such as rebinding the data source on postback.

How to place a different value within a GridView, if the source is a DataTable?

First of all, I've got a DataTable which stores data in a number of fields. One of these fields stores a value, which can either be '1', '0' or '-1'.
What I'm trying to accomplish is to fill a GridView with all the data contained in this DataTable, except for the previously mentioned field. Instead of this field, I would like to display a column which shows a different icon depending on the value (either 0, 1 or -1).
In other words, if a row contains a value of '0' in this field within the DataTable, I would like a red circle icon to appear in the equivalent cell within the GridView.
Could anyone kindly explain how this may be accomplished? Below is some code which may help to explain the situation further.
The GridView is filled with the data contained in the DataTable.
source = new DataSource();
TableGridView.DataSource = source.FillTable();
TableGridView.DataBind();
What should be done after this?
EDIT: Solution added as a comment below
Well there are different approaches:
1) you could add a field to your DataTable for the image and fill it with the url of the image that corresponds to the value. Add an image to the GridView and set it's ImageUrl to that field.
2) Add a template field to your GridView and add the 3 images. In the Visible property of the each image you set something like <% (int)Eval("MyNumericValue") == x %> (x being 0, 1 or -1) . That way only 1 image is shown, the others hidden (not rendered even).
from the hip:
<TemplateField>
<ItemTemplate>
<asp:image runat="server" imageurl="~/images/0.png" Visible='<%# (int)Eval("MyNumericValue") == 0 %>' />
<asp:image runat="server" imageurl="~/images/1.png" Visible='<%# (int)Eval("MyNumericValue") == 1 %>' />
<asp:image runat="server" imageurl="~/images/-1.png" Visible='<%# (int)Eval("MyNumericValue") == -1 %>' />
</ItemTemplate>
</TemplateField>
Solved: I created the TemplateField in ASP.NET code, and the other fields programmatically in the .cs class. Next, I added a chunk of code which switches round the order of the columns. Hope someone finds this helpful.

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