Insert multiline TextBox value copied from Excel to GridView using C# and VB.Net in ASP.Net

Hi bakhtawar,

I have created a sample which full fill your requirement you need to modify the code according to your need.

HTML

<div>
    <asp:TextBox ID="textData" OnTextChanged="Paste" AutoPostBack="true" TextMode="MultiLine"
        Rows="5" Width="200" runat="server" />
    <br />
    <asp:GridView ID="gvData" runat="server" />
</div>

C#

DataTable gridviewss;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        gridviewss = new DataTable();
        gridviewss.Columns.AddRange(new DataColumn[] { new DataColumn("Column3"), new DataColumn("Column4") });
        gridviewss.Rows.Add("123", "345");
        gridviewss.Rows.Add("1345", "235");
        gridviewss.Rows.Add("758", "3658");
        gridviewss.Rows.Add("958", "4235");
        gridviewss.Rows.Add("1d23", "7345");
        gridviewss.Rows.Add("13d45", "2235");
        ViewState["GridData"] = gridviewss;
        gvData.DataSource = gridviewss;
        gvData.DataBind();
    }
}

protected void Paste(object sender, EventArgs e)
{
    if (ViewState["GridData"] != null)
    {
        gridviewss = ViewState["GridData"] as DataTable;
        int previousColumnCount = gridviewss.Columns.Count;

        string cCon = Request.Form[textData.UniqueID];
        cCon = cCon.Replace("\r\n", "@");
        int i = 1;
        if (ViewState["ColumnCount"] != null)
        {
            i = Convert.ToInt32(ViewState["ColumnCount"]);
        }

        for (int a = 0; a < cCon.Split('@')[0].Split('\t').Length; a++)
        {
            if (!string.IsNullOrEmpty(cCon.Split('@')[0].Split('\t')[a].ToString()))
            {
                DataColumn newColumn = new DataColumn("excelcol" + i.ToString(), typeof(System.String));
                gridviewss.Columns.Add(newColumn);
                i++;
            }
        }

        ViewState["ColumnCount"] = i;
        int j = 0;
        int columnCount = gridviewss.Columns.Count;
        foreach (string row in cCon.Split('@'))
        {
            if (!string.IsNullOrEmpty(row))
            {
                foreach (string cell in row.Split(' '))
                {
                    if (!string.IsNullOrEmpty(cell))
                    {
                        int l = previousColumnCount;
                        if (cell.Split('\t').Length > 1)
                        {
                            for (int s = 0; s < cell.Split('\t').Length; s++)
                            {
                                if (!string.IsNullOrEmpty(cell.Split('\t')[s].ToString()))
                                {
                                    gridviewss.Rows[j][l] = cell.Split('\t')[s];
                                    l++;
                                }
                            }
                        }
                        else
                        {
                            gridviewss.Rows[j][l] = cell.Trim();
                            l++;
                        }
                        j++;
                    }
                }
            }
        }
        ViewState["GridData"] = gridviewss;
        gvData.DataSource = ViewState["GridData"] as DataTable;
        gvData.DataBind();
    }
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        gridviewss = New DataTable()
        gridviewss.Columns.AddRange(New DataColumn() {New DataColumn("Column3"), New DataColumn("Column4")})
        gridviewss.Rows.Add("123", "345")
        gridviewss.Rows.Add("1345", "235")
        gridviewss.Rows.Add("758", "3658")
        gridviewss.Rows.Add("958", "4235")
        gridviewss.Rows.Add("1d23", "7345")
        gridviewss.Rows.Add("13d45", "2235")
        ViewState("GridData") = gridviewss
        gvData.DataSource = gridviewss
        gvData.DataBind()
    End If
End Sub

Protected Sub Paste(sender As Object, e As EventArgs)
    If ViewState("GridData") IsNot Nothing Then
        gridviewss = TryCast(ViewState("GridData"), DataTable)
        Dim previousColumnCount As Integer = gridviewss.Columns.Count

        Dim cCon As String = Request.Form(textData.UniqueID)
        cCon = cCon.Replace(vbCr & vbLf, "@")
        Dim i As Integer = 1
        If ViewState("ColumnCount") IsNot Nothing Then
            i = Convert.ToInt32(ViewState("ColumnCount"))
        End If

        For a As Integer = 0 To cCon.Split("@"c)(0).Split(ControlChars.Tab).Length - 1
            If Not String.IsNullOrEmpty(cCon.Split("@"c)(0).Split(ControlChars.Tab)(a).ToString()) Then
                Dim newColumn As New DataColumn("excelcol" + i.ToString(), GetType(System.String))
                gridviewss.Columns.Add(newColumn)
                i += 1
            End If
        Next
        ViewState("ColumnCount") = i
        Dim j As Integer = 0
        Dim columnCount As Integer = gridviewss.Columns.Count
        For Each row As String In cCon.Split("@"c)
            If Not String.IsNullOrEmpty(row) Then
                For Each cell As String In row.Split(" "c)
                    If Not String.IsNullOrEmpty(cell) Then
                        Dim l As Integer = previousColumnCount
                        If cell.Split(ControlChars.Tab).Length > 1 Then
                            For s As Integer = 0 To cell.Split(ControlChars.Tab).Length - 1
                                If Not String.IsNullOrEmpty(cell.Split(ControlChars.Tab)(s).ToString()) Then
                                    gridviewss.Rows(j)(l) = cell.Split(ControlChars.Tab)(s)
                                    l += 1
                                End If
                            Next
                        Else
                            gridviewss.Rows(j)(l) = cell.Trim()
                            l += 1
                        End If
                        j += 1
                    End If
                Next
            End If
        Next
        ViewState("GridData") = gridviewss

        gvData.DataSource = TryCast(ViewState("GridData"), DataTable)
        gvData.DataBind()
    End If
End Sub

ScreenShot