i have a gridview in which i am using checkbox in each row. i am trying to access checkbox of each row and trying to find out which checkboxes have been checked.buut when i try to run the below code.the condition always stands to be false and the inner if condition is never reached by the code.kindly help me.thanks in advance.
protected void btn_3id_Click(object sender, EventArgs e)
{
string str = "";
string srr = "";
for (int i = 0; i < GridView1.Rows.Count;i++ )
{
CheckBox chk = (CheckBox)GridView1.Rows[i].FindControl("CheckBox1");
if (chk.Checked==true)
{
if (str == "")
{
str = GridView1.Rows[i].Cells[0].Text.ToString();
}
else
{
srr = str + "," + GridView1.Rows[i].Cells[0].Text.ToString();
}
}
}
Session["Card_id"] = str;
Response.Redirect("ID.aspx");
}
The code looks fine.
The problem could be you are binding the gridview at page load.
Try grid binding in the following section of page load
if(!Page.IsPostBack)
{
//code to bind the gridview
}
I can only guess that you are binding your gridview on each page load without checking PostBack. That is causing the checkbox to loose its current state. So where you are assigning the DataSource to the Gridview , Check for PostBack like:
if(!Page.IsPostBack)
{
GridView1.DataSource = yourDataSource;
GridView1.DataBind();
}
also you can do some minor improvements in your code like your check:
if(chk.Checked == true)
can be replaced as:
if(chk.Checked) //Since it returns a bool value.
You can omit multiple string variables for concatenation. Its better if you use StringBuilder, (See why it is better) so your code would be:
protected void btn_3id_Click(object sender, EventArgs e)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < GridView1.Rows.Count;i++ )
{
CheckBox chk = (CheckBox)GridView1.Rows[i].FindControl("CheckBox1");
if (chk.Checked==true)
{
sb.Append() GridView1.Rows[i].Cells[0].Text.ToString();
}
}
Session["Card_id"] = sb.ToString();
Response.Redirect("ID.aspx");
}
if(!Page.IsPostBack)
{
//
}
Postback plays important role in cs file. If you are clearing values on page load , you will null values of checkbox.
You code is fine.
Just try to do this...
Related
I have a gridview with many columns. It's sortable, Allow Sorting="True", each column has Sort Expression. For each column sorting works just fine, except for 10 columns that have dynamic headers that I assign in Row_Databound event:
protected void gvSearchResults_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
for (int i = 1; i < 11; i++)
{
if (Session["Label" + i.ToString()] !=null)
{
e.Row.Cells[i].Text = Session["Label" + i.ToString()].ToString();
}
}
}
}
These 10 columns are not clickable. Is there any way to make them clickable? Everything else in these columns is enabled for sorting.
I've got some suggestions from a different forum about creating columns in Page_Load or Page_Init events, but this probably won't work for me.
Thank you.
You can replace the text of the existing LinkButton in the header cell:
protected void gvSearchResults_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
for (int i = 1; i < 11; i++)
{
string caption = Session["Label" + i.ToString()] as string;
if (caption != null)
{
TableCell headerCell = e.Row.Cells[i];
LinkButton lnkSort = headerCell.Controls[0] as LinkButton;
lnkSort.Text = caption;
}
}
}
}
It can be done. If you look at the HTML code you will see something similar to this as the link for sorting the GridView.
yourColumnName
We need to recreate that link in the RowDataBound function.
for (int i = 1; i < 11; i++)
{
//first we cast the sender as a gridview
GridView gv = sender as GridView;
//get the unique ID of the gridview, this is different from ClientID which you normally would use for JavaScipt etc
string uniqueID = gv.UniqueID;
//then get the SortExpression for the column
string sortExpression = gv.Columns[i].SortExpression;
//get the new column name from the session
string yourColumnName = string.Empty;
if (Session["Label" + i.ToString()] != null)
{
yourColumnName = Session["Label" + i.ToString()].ToString();
}
//and then we fill the header with the new link
e.Row.Cells[i].Text = "" + yourColumnName + "";
}
However for this to work, enableEventValidation has to be set to false, which is NOT recommended. Otherwise you will get the "Invalid postback or callback argument" error.
Better would be changing the column names somehow before the data is bound to the gridview.
Thank you very much for your help. The solution with LinkButton worked great for me:
protected void gvSearchResults_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
for (int i = 1; i < 11; i++)
{
if (Session["Label" + i.ToString()] !=null)
{
((LinkButton)(e.Row.Cells[i].Controls[0])).Text = Session["Label" + i.ToString()].ToString();
}
}
}
}
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.
namespace Dynamic_Controls.Dropdowndynamic
{
public partial class DropdowndynamicUserControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
if (ControlCount != 0)
{
Recreatecontrols();
}
}
private void Recreatecontrols()
{
// createtextboxes(ControlCount);
createtextboxes(2);
}
protected void createtextboxes(int ControlCount)
{
DynPanel.Visible = true;
for (int i = 0; i <= ControlCount; i++)
{
TextBox tb = new TextBox();
tb.Width = 150;
tb.Height = 18;
tb.TextMode = TextBoxMode.SingleLine;
tb.ID = "TextBoxID" + this.DynPanel.Controls.Count;
tb.Text = "EnterTitle" + this.DynPanel.Controls.Count;
tb.Load+=new EventHandler(tb_Load);
tb.Visible = true;
tb.EnableViewState = true;
DynPanel.Controls.Add(tb);
DynPanel.Controls.Add(new LiteralControl("<br/>"));
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 newControlCount = Int32.Parse(DropDownList1.SelectedValue);
//createtextboxes(newControlCount);
//ControlCount+=newControlCount;
createtextboxes(2);
}
protected void Button1_Click(object sender, EventArgs e)
{
readtextboxes();
}
public void readtextboxes()
{
string x = string.Empty;
for (int a = 0; a < DynPanel.Controls.Count; a++)
{
foreach (Control ctrl in DynPanel.Controls)
{
if (ctrl is TextBox)
{
x = ((TextBox)ctrl).Text;
}
x+=x+("\n");
}
Result.Text = x;
}
}
private Int32 ControlCount
{
get
{
if (ViewState["ControlCount"] == null)
{
ViewState["ControlCount"] = 0;
}
return (Int32)ViewState["ControlCount"];
}
set
{
// ViewState["ControlCount"] = value;
ViewState["ControlCount"] = 2;
}
}
private void tb_Load(object sender, EventArgs e)
{
LblInfo.Text = ((TextBox)sender).ID + "entered";
}
}
}
Are you adding these controls dynamically in Page_Load (by, I'm assuming, calling your AddRequiredControl() method)? If so, is it wrapped in a conditional which checks for IsPostBack? The likely culprit is that you're destructively re-populating the page with controls before you get to the button click handler, so all the controls would be present but empty (as in an initial load of the page).
Also, just a note, if you're storing each control in _txt in your loop, why not refer to that variable instead of re-casting on each line. The code in your loop seems to be doing a lot of work for little return.
You need to recreate any dynamically created controls on or before Page_Load or they won't contain postback data.
I'm not entirely clear what happens on DropdownList changed - are you trying to preserve anything that has been entered already based on the textboxes previously generated?
In any event (no pun intended) you need to recreate exactly the same textboxes in or before Page_Load that were there present on the postback, or there won't be data.
A typical way to do this is save something in ViewState that your code can use to figure out what to recreate - e.g. the previous value of the DropDownList. Override LoadViewState and call the creation code there in order to capture the needed value, create the textboxes, then in the DropDownList change event, remove any controls that may have been created in LoadViewState (after of course dealing with their data) and recreate them based on the new value.
edit - i can't figure out how your code works now, you have AddRequiredControl with parameters but you call it with none. Let's assume you have a function AddRequiredControls that creates all textboxes for a given DropDownList1 value, and has this signature:
void AddRequiredControls(int index)
Let's also assume you have a PlaceHolder called ControlsPlaceholder that will contain the textboxes. Here's some pseudocode:
override void LoadViewState(..) {
base.LoadViewState(..);
if (ViewState["oldDropDownIndex"]!=null) {
AddRequiredControls((int)ViewState["oldDropDownIndex"]);
}
}
override OnLoad(EventArgs e)
{
// process data from textboxes
}
void DropDownList1_SelectedIndexChanged(..) {
ControlsPlaceholder.Controls.Clear();
AddRequiredControls(DropDownList1.SelectedIndex);
ViewState["oldDropDownIndex"]=DropDownList1.SelectedIndex;
}
I have SqlDataSource and GridView on web form. GridView.DataSourceID = mySqlDataSource.
When I call myGridView.DataBind(), all data successfully bind on the page.
How is it possible to read already got data from mySqlDataSource or myGridView objects as DataTable or DataView? Thanks
The data in the gridview can read by using FindControl property of Gridview control. For example, for reading values set in the Checkbox column in the grid.
for (i = 0; i < GridView1.Rows.Count; i++)
{
CheckBox chk = (CheckBox)GridView1.Rows[i].FindControl("checkbox1");
//here code for using value captured in chk
}
Provided your data set isn't gigantic, you could store it in the Session, bind your GridView to the Session data, and then re-use the Session data in your other web objects.
Your code would then look something like this (you'll have to forgive any minor inaccuracies -- I'm away from my development box at the moment):
protected override OnInit(object sender, EventArgs e)
{
base.OnInit();
if (Page.IsPostback == false)
{
SetSessionData();
}
//
// Set your GridView, DataTable, DataView, etc. events here.
//
}
void SetSessionData();
{
List<YourDataBoundObject> myDataBoundObject = GetYourDataBoundObject(); // Or Collection<T>, IEnumerable<T>, etc.
Session["data"] = myDataBoundObject;
}
void YourGridView_Load(object sender, EventArgs e)
{
BindYourGridView();
}
void BindYourGridView()
{
YourGridView.DataSource = GetSessionData();
YourGridView.DataBind();
}
List<YourDataBoundObject> GetSessionData()
{
return (List<YourDataBoundObject>) Session["data"];
}
void YourDataTable_Load(object sender, EventArgs e)
{
BindYourDataTable();
}
void BindYourDataTable()
{
YourDataTable.DataSource = GetSessionData();
YourDataTable.DataBind();
}
am trying to get users to enter some details into a textbox in form1 and get the entry validated against the database. if the entry is correct, form2 loads with other texboxes including the one they made entries into. however i dont want them to make any changes to the textboxes they entered values into previously neither should they have to re-enter the values again.
how do i get the values in the textboxes to move from form1 to form2?
the code below shows what ive done with both forms but the second form dosent display the items in the textboxes when the form is loaded.
first form
protected void Button1_Click(object sender, EventArgs e)
{
string strConn;
strConn = "Provider=MIcrosoft.Jet.OLEDB.4.0;data Source=" +
Server.MapPath("App_Data/test.mdb");
OleDbConnection mDB = new OleDbConnection(strConn);
mDB.Open();
prodSnStr = pSnTextBox.Text;
purDate = Convert.ToDateTime(purDateTextBox.Text);
string dateStr = purDateTextBox.Text;
productClass aProduct = new productClass();
if (aProduct.Prods(mDB, prodSnStr, purDate))
{
Session["ProdSn"] = pSnTextBox.Text;
Session["PurDate"] = purDateTextBox.Text.ToString();
Response.Redirect("Warranty.aspx");
}
else
{
//error message
}
}
form two
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
if (Request.QueryString["ProdSn"] != "")
{
pSNoTextBox.Text = Request.QueryString["ProdSn"];
if (Request.QueryString["PurDate"] != "")
{
dateTextBox.Text = Request.QueryString["PurDate"];
}
else
{
//error message to display
}
}
else
{
//error message to display
}
}
eagaerly waiting for your responses..thanks..
In your code you are putting the values on one page into the session:
Session["ProdSn"] = pSnTextBox.Text;
Session["PurDate"] = purDateTextBox.Text.ToString();
However you are trying to read them out on the 2nd page from the Request collection:
if (Request.QueryString["ProdSn"] != "")
{
pSNoTextBox.Text = Request.QueryString["ProdSn"];
if (Request.QueryString["PurDate"] != "")
{
dateTextBox.Text = Request.QueryString["PurDate"];
}
This makes no sense. If you want to use the session, you must also get the values back out from the session object.
Personally I would look into Cross Page postbacks and Server.Transfer combined with Page.PreviousPage. Just make sure you don't set preserveForm parameter to false if using Server.Transfer.
You aren't passing your values as a query string. If you were your Response.Redirect would look like this:
Response.Redirect("Warranty.aspx?ProdSn=something&PurDate=something");
Instead since you are saving these values in a Session variable try this:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
if (Session["ProdSn"] != "")
{
pSNoTextBox.Text = Session["ProdSn"];
if (Session["PurDate"] != "")
{
dateTextBox.Text = Session["PurDate"];
}
else
{
//error message to display
}
}
else
{
//error message to display
}
}
In the button_click of the first form i entered this code
Session["ProdSn"] = pSnTextBox.Text;
Session["PurDate"] = purDateTextBox.Text.ToString();
Response.Redirect("Warranty.aspx?ProdSn=" + Server.UrlEncode(pSnTextBox.Text) +
"&PurDate=" + Server.UrlEncode(purDateTextBox.Text));
and then in the Page_load event of the second form i did this..
string value = Request["ProdSn"];
string value1 = Request["PurDate"];
pSnTextBox.Text = value;
purDateTextBox.Text = value1;
no hassle sustained....easy and perfectly working....
thank for ya'11 helping....
am very grateful
your asp.net page must post your data to second page.
just set your buttons PostBackUrl attribute.
<asp:Button ID="Button1" runat="server" Text="Button" PostBackUrl="target.aspx" />
I do not understand while you are making things complex.
When users clicks the button all data will be send to your target page.