如何验证用户是否在C＃的datagridview单元格中输入整数？

Question

在我的Windows应用程序“ Purchase Order Datagridview”中，如下所示

如果用户在当前行的数量单元格中未输入数字值，则会引发异常。我想知道如果我在此错误消息中按ok按钮后如何继续操作。我尝试了以下代码。但是它将持续弹出此消息。如何解决此问题。

 private void dataGridView1_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e)
    {
        try
        {
            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                double unitPrice = 0;
                int quantity = 0;
                quantity = Convert.ToInt32(row.Cells[dataGridView1.Columns[2].Index].Value);
                unitPrice = Convert.ToDouble(row.Cells[dataGridView1.Columns[3].Index].Value);
                row.Cells[dataGridView1.Columns[4].Index].Value = quantity * unitPrice;
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(" Error " + ex.Message);
            dataGridView1.CurrentRow.Cells[2].Value = DBNull.Value;
        }
    }

Answer 1

请参阅this.use int.TryParse

  private void dataGridView1_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e)
        {
            try
            {
                foreach (DataGridViewRow row in dataGridView1.Rows)
                {
                    double unitPrice = 0;
                    int quantity = 0;
                    int.TryParse(row.Cells[dataGridView1.Columns["Enter Your Column Name here"].Index].Value, out quantity))
                    if(!(quantity > 0))
                    {
                     MessageBox.Show(" Error ");
                     return;
                    }
                    unitPrice = Convert.ToDouble(row.Cells[dataGridView1.Columns["Enter Your Column Name here"].Index].Value);
                    row.Cells[dataGridView1.Columns["Enter Your Column Name here"].Index].Value = quantity * unitPrice;
                }
            }
            catch (Exception ex)
            {
            }
        }

完整示例以了解Tryparse：-

 class Program
    {
        static void Main(string[] args)
        {
            string abc = "10abc";
            int result = 0;
            int.TryParse(abc, out result);
            Console.WriteLine(result);
            Console.ReadKey();
        }
    }

我如何测试：-

class Program
{
    static void Main(string[] args)
    {
        string abc = "10abc";
        int result = 0;
        int.TryParse(abc, out result);
        if(!(result>0))
        {
            Console.Write("Enter Numeric Value");
        }
        Console.ReadKey();
    }
}