Incorrect Value

Ramco Ramco

I have below code . I have attached image. When i loop thru Gridview it should show Data value but it shows

When i am tryying this it gives error - Object reference mot set to an instance of the Object.

foreach (GridViewRow gr in grdPlanning.Rows)
{
    //string sessionDate = "";
    if (gr.RowType == DataControlRowType.DataRow)
    {

        if (gr.Cells[0].Text == "146")
        {
            string sign5 = ((TextBox)gr.FindControl("txtDate")).Text;
        }
    }
}

protected void gr_RowDataBound(object sender, GridViewRowEventArgs e)
{
    try
    {
        if (e.Row.RowType != DataControlRowType.DataRow)
            return;
        e.Row.Cells[0].HorizontalAlign = HorizontalAlign.Center;

        TextBox txtDate = new TextBox();
        txtDate.CssClass = "form-control";
        txtDate.DataBind();
        e.Row.Cells[e.Row.Cells.Count - 1].Controls.Add(txtDate);
    }
}

Thanks

4 Replies

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Ramco Ramco3y ago
Hi Tuhin

If u see in my earlier code in gr_RowDataBound i have defined txtDate. Why this issue is coming

Thanks
0
Tuhin Paul3y ago
The `FindControl` method returns `null` if the control is not found, so you should check if the result is not `null` before using it. Here's an example:
```
TextBox txtDate = gr.FindControl("txtDate") as TextBox;
if (txtDate != null)
{
    // Use the txtDate control
}
```
Alternatively, you can use C# 8's "nullable reference types" feature to specify that `txtDate` may be null:
```
if (gr.FindControl("txtDate") is TextBox? txtDate)
{
    // Use the txtDate control
}
 
```
Note the use of the `?` after the `TextBox` type to indicate that the variable can be null.
0

Ramco Ramco3y ago

Hi Tuhin

When i write this it gives null

if (gr.FindControl("txtDate") is TextBox txtDate) // use pattern matching to check if the control is found and cast it to TextBox
                        {

Thanks

Tuhin Paul3y ago
Part 1:

The ` ` that you see in the GridView cell is a non-breaking space character, which is used to create space between words or characters without allowing line breaks. In your code, you are checking if `gr.Cells[0].Text == "146"`, which means you are comparing the text in the first cell of the GridView row to the string "146". If the text in the cell is actually ` ` (which is not visible to the user), then the condition will not be true. To check for the ` ` character, you can use `Server.HtmlDecode` method to decode the cell's text and replace ` ` with an empty string.
```
foreach (GridViewRow gr in grdPlanning.Rows)
{
    if (gr.RowType == DataControlRowType.DataRow)
    {
        string cellText = Server.HtmlDecode(gr.Cells[0].Text).Trim(); // decode the text and remove any leading/trailing spaces
        if (cellText == "146")
        {
            string sign5 = ((TextBox)gr.FindControl("txtDate")).Text;
        }
    }
}
```
Part 2:

Regarding the error "Object reference not set to an instance of the Object", it means that you are trying to access a property or method of an object that is `null`. In your case, it is possible that `gr.FindControl("txtDate")` is returning `null`, which means that the TextBox control with ID "txtDate" is not found in the current GridView row. You can add a null check to avoid this error:
```
foreach (GridViewRow gr in grdPlanning.Rows)
{
    if (gr.RowType == DataControlRowType.DataRow)
    {
        if (gr.FindControl("txtDate") is TextBox txtDate) // use pattern matching to check if the control is found and cast it to TextBox
        {
            string cellText = Server.HtmlDecode(gr.Cells[0].Text).Trim();
            if (cellText == "146")
            {
                string sign5 = txtDate.Text;
            }
        }
    }
}
```
0