!IsPostBack returns always true - asp.net

I am trying to implement search operation for my gridview.When I load my page first time !IsPostBack works fine but when I click on the search button my page loads again and !IsPostBack returns true value.So, I was not able to perform my search operation
this is my code.
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
((Label)Master.FindControl("Label1")).Text = (string)Session["sname"];
fillData();
}
}
public void fillData()
{
if (con.State == ConnectionState.Open)
{
con.Close();
}
con.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM EBR_Supplier where DeleteFlag=" + 0 + " ORDER BY RowId ASC", con);
SqlDataAdapter adap = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
adap.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
fillData();
}
protected void search_Click(object sender, EventArgs e)
{
string id = txtid.Text;
if (con.State == ConnectionState.Open)
{
con.Close();
}
con.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM EBR_Supplier where DeleteFlag=" + 0 + " and SupplierId='" + id + "' ORDER BY RowId ASC", con);
SqlDataAdapter adap = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
adap.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}

I have found the solution myself I have a form control on my master page.I removed that it helped me.I thank you all for giving time to my question.

Related

Gridview doesn't refresh after deleting a row

I have a GridView in an UpdatePanel.
When I add a row, it gets updated right away. The problem is that, when I delete a row, it doesn't update the GridView.
What can be done?
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Request.QueryString["EventId"] != null)
{
ExtractEventData();
GridView1.DataSourceID = "SqlDataSource1";
}
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
string CS =
ConfigurationManager.ConnectionStrings["ss"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand("spInsertComment", con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#Comment", txtComment.Text);
cmd.Parameters.AddWithValue("#Eventid", lblEventId.Text);
cmd.Parameters.AddWithValue("#UserId", Session["UserId"].ToString());
cmd.ExecuteNonQuery();
txtComment.Text = "";
GridView1.DataSourceID = "SqlDataSource1";
GridView1.DataBind();
}
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "Delete")
{
int id = Int32.Parse(e.CommandArgument.ToString());
string CS = ConfigurationManager.ConnectionStrings["ss"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand(
"Delete from tblEventComments WHERE CommentId = #CommentId", con);
cmd.Parameters.AddWithValue("#CommentId", id);
cmd.ExecuteNonQuery();
GridView1.DataSourceID = "";
GridView1.DataSourceID = "SqlDataSource1";
GridView1.DataBind();
}
}
}
I have also tried removing the datasource1 connection from GridView and then re-assigned it. Still it doesn't seem to work, the way I need it to.
I don't think you will need the GridView markup here, however you can ask for it if necessary.
According to this post, you should delete the row using GridView.DeleteRow method.

lable is not showing any output for the dropdown list selection

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["LibraryConnectionString"].ConnectionString);
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ddlbookavail.Items.Add(new ListItem("select", "-1"));
ddlbookavail.AppendDataBoundItems = true;
SqlCommand cmd = new SqlCommand("select * from tblbookinfo", con);
con.Open();
ddlbookavail.DataSource = cmd.ExecuteReader();
ddlbookavail.DataTextField = "Name";
ddlbookavail.DataValueField = "Id";
ddlbookavail.DataBind();
con.Close();
txtdate.Text = DateTime.Now.Date.ToString("dd/MM/yyyy");
}
in my design page i put the sql datasource from data and got this connection srting

populate gridview on dropdownlist indexchanged

i have gridview which populate date from database i want to change seclected data on dropdown SelectedIndexChanged when i select the first index it selected data from database when i chang selections it get another data try this code but nosense this is my code
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindData();
}
}
private void BindData()
{
if (ddlTguidedit.SelectedIndex==0)
{
string strQuery = "SELECT [Pdfid],[Arpdf_name],[Arpdf_des],[pdf_date] FROM [books_alaa].[dbo].[Tbl_uploadpdf]";
SqlCommand cmd = new SqlCommand(strQuery);
GridView1.DataSource = GetData(cmd);
GridView1.DataBind();
}
else
{
string strQuery = " SELECT Pdfid, Enpdf_name AS Arpdf_name, Enpdf_des AS Arpdf_des, pdf_url, pdf_date FROM Tbl_uploadpdf";
SqlCommand cmd = new SqlCommand(strQuery);
GridView1.DataSource = GetData(cmd);
GridView1.DataBind();
}
}
private DataTable GetData(SqlCommand cmd)
{
DataTable dt = new DataTable();
SqlConnection con = new SqlConnection(strConnString);
SqlDataAdapter sda = new SqlDataAdapter();
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
con.Open();
sda.SelectCommand = cmd;
sda.Fill(dt);
return dt;
}
protected void ddlTguidedit_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlTguidedit.SelectedIndex == 0)
{
string strQuery = "SELECT [Pdfid],[Arpdf_name],[Arpdf_des],[pdf_date] FROM [books_alaa].[dbo].[Tbl_uploadpdf]";
SqlCommand cmd = new SqlCommand(strQuery);
GridView1.DataSource = GetData(cmd);
GridView1.DataBind();
}
else
{
string strQuery = " SELECT Pdfid, Enpdf_name AS Arpdf_name, Enpdf_des AS Arpdf_des, pdf_url, pdf_date FROM Tbl_uploadpdf";
SqlCommand cmd = new SqlCommand(strQuery);
GridView1.DataSource = GetData(cmd);
GridView1.DataBind();
}
}
why it doesnt work ??
Remove BindData() from !IsPostBack(). You are loading the grid data on DropDownList SelectedIndexChanged. There is no need of BindData() function to be in !IsPostBack(). BindData() function always loads no matter at what index the DropDownList is, it will always take the index as 0.

Making code duplication to refresh the gridview in asp.net

I am trying to update the gridview after updating some data. Here is my code:
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = University.GetConnectionString();
con.Open();
string query = "select [ID],[Name],[Surname],[level] from StudentTable order by ID";
SqlCommand cmd = new SqlCommand(query, con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
studentLevel.DataSource = dt;
studentLevel.DataBind();
con.Close();
}
protected void studentLevel_RowCommand(object sender, GridViewCommandEventArgs e)
{
int row = -1;
int.TryParse(e.CommandArgument as string, out row);
GridViewRow gdrow = studentLevel.Rows[row];
DataRow dr = ((DataTable)studentLevel.DataSource).Rows[gdrow.DataItemIndex];
string id = dr["ID"].ToString();
Student student = new Student(Convert.ToInt32(id), "", "", "", "", "", "", "");
if (e.CommandName == "Undergraduate")
student.setLevelRole(new UnderGraduateStudent());
else if (e.CommandName == "Graduate")
student.setLevelRole(new GraduateStudent());
student.writeLevelRole(id);
SqlConnection con = new SqlConnection(); //HERE IS DUPLICATION
//refresh the gridview on the page
con.ConnectionString = University.GetConnectionString();
con.Open();
string query = "select [ID],[Name],[Surname],[level] from StudentTable order by ID";
SqlCommand cmd = new SqlCommand(query, con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
studentLevel.DataSource = dt;
studentLevel.DataBind();
con.Close();
}
The problem is, if i do not write the last 12 lines of the code, which is the same code as page_load method, the gridview does not refresh itself on the page. Waht can i do to avoid this?
Thanks
You should provide a method that loads the data and databinds the GridView, for example DataBindGrid:
private void DataBindGrid()
{
using(var con = new SqlConnection(University.GetConnectionString()))
{
con.Open();
string query = "select [ID],[Name],[Surname],[level] from StudentTable order by ID";
SqlCommand cmd = new SqlCommand(query, con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
studentLevel.DataSource = dt;
studentLevel.DataBind();
}
}
Then you can call it from wherever you need. If you want to change something you have only one place to maintain which is less error-prone.
Note that you should databind the GridView only if(!IsPostBack) if you use ViewState(default):
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostback))
DataBindGridView();
}
and in RowCommand
protected void studentLevel_RowCommand(object sender, GridViewCommandEventArgs e)
{
// ... update student ... then
DataBindGridView();
}

Paging in Gridview not working 2nd page data not showing data?

my gridview
<div style="margin-left: 280px">
<asp:GridView ID="exportGrdVw" runat="server" BackColor="White"
AllowPaging="True" PageSize="3"
OnPageIndexChanging="exportGrdVw_PageIndexChanging"
onpageindexchanged="exportGrdVw_PageIndexChanged">
</asp:GridView>
</div>
my code
SqlConnection con = new SqlConnection("server=acer-Pc\\Sql;database=MYDB;trusted_connection=yes");
//DataSet ds = new DataSet();
DataTable table = new DataTable();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SqlDataAdapter da = new SqlDataAdapter("select customername,contactno,address from employee ", con);
da.Fill(table);
BindEmployee();
}
}
public void BindEmployee()
{
exportGrdVw.DataSource = table;
exportGrdVw.DataBind();
}
protected void exportGrdVw_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
exportGrdVw.PageIndex = e.NewPageIndex;
BindEmployee();
}
the problem is gridview is displaying but when i click page 2. 2nd page data is not showing (blank). pls help me to solve this problem.
see that the code is correct or not
Use like below
SqlConnection con = new SqlConnection("server=acer-Pc\\Sql;database=MYDB;trusted_connection=yes");
//DataSet ds = new DataSet();
DataTable table = new DataTable();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindEmployee();
}
}
public void BindEmployee()
{
SqlDataAdapter da = new SqlDataAdapter("select customername,contactno,address from employee ", con);
da.Fill(table);
exportGrdVw.DataSource = table;
exportGrdVw.DataBind();
}
protected void exportGrdVw_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
exportGrdVw.PageIndex = e.NewPageIndex;
BindEmployee();
}
Your datatable gets initialize in every page load so you need to get the datatable
everytime before binding it to grid.
Set your page Index before binding it to grid
So your code should be like this
public void BindEmployee(int newPageIndex = -1)
{
SqlDataAdapter da = new SqlDataAdapter("select customername,contactno,address from employee ", con);
da.Fill(table);
exportGrdVw.PageIndex = newPageIndex;
exportGrdVw.DataSource = table;
exportGrdVw.DataBind();
}
No need to call database on exportGrdVw_PageIndexChanging. Just declare DataTable table as static
You can try this:
GridView1.PageIndex = e.NewPageIndex;
SqlCommand cmd = new SqlCommand("Select * from Emp_Data ORDER BY [ID] DESC", con);
SqlDataAdapter DA1 = new SqlDataAdapter(cmd);
DA1.Fill(DT1);
GridView1.DataSource = DT1;
GridView1.DataBind();

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