Object reference not set to an instance of an object in textbox

JC Ballo

Good day guys can you help me, I have this error called Object reference not set to an instance of an object in my code. here is the code.

Also this is the winforms

I want the data to fill in the textboxes.
This is the data

and this is my procedure

this code is actually from my previous questions I have to change because of some circumstances.

It actually work once but the other day when I want to try it, it is not working I'm sorry.

7 Replies

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Tuhin Paul3y ago
Accepted answer
There seems to be a typo in the code. In the if block, DBNull.Value is being compared with the value variable using the equality operator (==), which will always return false. Instead, it should be checked for inequality with the value variable.
```
object value = dataSet.Tables[1].Rows[i]["TdateInOut"];
if (value != null && value != DBNull.Value)
{
   TimeIn.Text = dataSet.Tables[1].Rows[i]["TdateInOut"].ToString();
}
else
{
   // handle the case where the value is null or DBNull.Value
}
```
TdateInOut column name is misspelled in the code snippet. It should match the correct column name in the dataset.
0
JC Ballo3y ago
Tuhin Paul it works but I also have to change some but all in all it works
0
JC Ballo3y ago

Hello Sir. Tuhin Paul

I tried your codes and still the error persist and when I look at the TIME.text the output is still null.

PS: I changed the text only because I changed all the textboxes into TIME1.text to TIME30.
0
JC Ballo3y ago
Hello Sir. Jignesh Kumar the codes work but there is no data in the textboxes

0
Jignesh Kumar3y ago
Hi JC,

I am able to see the column "TDateINOut" in your data set, Can you please put debugger in you code and check Table[1]. you are getting this column or not ?
```
 object value = dataSet.Tabels[1].Rows[i]["TdateInOut"];
    if (value != null && value != DBNull.Value)
   {
      TimeIn.Text = dataSet.Tabels[1].Rows[i]["TdateInOut].Tostring();
   }
    else
   {}
```
+1
JC Ballo3y ago
Hello Sir. Jignesh Kumar I tried using your codes but still not working.

0

Jignesh Kumar3y ago

Hello,

You are trying to cast null value due to that you are getting this error. Please do null check before convert to tostring(),

TimeIn.Text = dataSet.Tabels[1].Rows[i]["TdateInOut"] != null ? dataSet.Tabels[1].Rows[i]["TdateInOut].Tostring() : "";

TimeIn.Text = dataSet.Tabels[1].Rows[i]["TdateInOut]?.Tostring();