使用int.parse添加值

Question

I'm looping through some excel cells to sum the values of the cells, some of the cells are empty and i'm getting a Input string was not in the correct format error when I pass them. Here's my code:

     int total = 0;
        int rowstart = 4;
        while (ws.Cells[rowstart, 1].Value.ToString() != "")
        {
           if (ws.Cells[rowstart, 1].Value.ToString() !=
                      ws.Cells[rowstart + 1, 1].Value.ToString())
           {
               ws.InsertRow(rowstart + 1, 1);
               ws.Cells[rowstart + 1, 3].Value = total;
           }
           else
           {
         total = total + int.Parse(ws.Cells[rowstart, 3].Value.ToString()); 
// I'm adding the value of Column 3 to the variable total, 
I get the error if the cell is empty
               rowstart = rowstart + 1;
           }
        }

I was thinking it's because you can't parse an empty string, so how do I just add 0 if the cell is empty?

Answer 1

Use int.TryParse :

int parsed;
int.TryParse(ws.Cells[rowstart, 3].Value.ToString(), out parsed)
total += parsed;

parsed will be 0 if the string wasn't a number.

Answer 2

Use int.TryParse instead of int.Parse

int total = 0;
int rowstart = 4;

while (ws.Cells[rowstart, 1].Value.ToString() != "")
{
int val=0;
if (ws.Cells[rowstart, 1].Value.ToString() != ws.Cells[rowstart + 1, 1].Value.ToString())
{
   ws.InsertRow(rowstart + 1, 1);
   ws.Cells[rowstart + 1, 3].Value = total;
}
else
{ 
int.TryParse(ws.Cells[rowstart, 3].Value.ToString(), out val);
    total = total + val; 
   // I'm adding the value of Column 3 to the variable total, I get the error if the cell is empty
   rowstart = rowstart + 1;
}

}

Answer 3

Try the code below

else
{ 
  If (int.TryParse(ws.Cells[rowstart, 3].Value.ToString(), out result))
    total = total +int.Parse(ws.Cells[rowstart, 3].Value.ToString());

   rowstart = rowstart + 1;
}