Thursday, September 26, 2019

c# - NullReferenceException in string.IsNullOrWhiteSpace() and string.IsNullOrEmpty()



I'm checking the cell values of cells of a column that might or not be empty/null so I needed something to avoid a NullReferenceException.



How do I do that since even with the IsNullOrWhiteSpace() and IsNullOrEmpty() I get that exception somehow.



Here's part of the code I'm using:




s = "Total = " + dataGridView1.Rows[0].Cells.Count +
"0 = " + dataGridView1.Rows[0].Cells[0].Value.ToString() +
"/n 1 = " + dataGridView1.Rows[0].Cells[1].Value.ToString() +
"/n 2= " + dataGridView1.Rows[0].Cells[2].Value.ToString() +
"/n 3 = " + dataGridView1.Rows[0].Cells[3].Value.ToString() +
"/n 4= " + dataGridView1.Rows[0].Cells[4].Value.ToString() +
"/n 5 = " + dataGridView1.Rows[0].Cells[5].Value.ToString() +
"/n 6= " + dataGridView1.Rows[0].Cells[6].Value.ToString() +
"/n 7 = " + dataGridView1.Rows[0].Cells[7].Value.ToString();


if (string.IsNullOrEmpty(dataGridView1.Rows[0].Cells[8].Value.ToString()))
{

}
else
{
s += "/n 8 = " + dataGridView1.Rows[0].Cells[8].Value.ToString();
}



I've tried those methods I've tried putting it ==null, I've tried !=null. What else is there or what am I doing wrong exactly and how do I do it right?


Answer



the are a lot of places you code could throw that exception ..



dataGridView1.Rows[0]  //here
.Cells[0] //here
.Value //and here
.ToString()



I belive you don't need the ToString() just type:



"... "+ dataGridView1.Rows[0].Cells[0].Value


in your ifstatement do this:



if (string.IsNullOrEmpty(dataGridView1.Rows[0].Cells[8].Value as string))


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