Datagridview Error :: Index超出范围。我怎么能解决它？

Question

我有这个表单应用程序项目。我上传销售字段的快照。有两个datagridview。底部datagirdview包含TAX details。底部datagrid的包含来自database except “Amount” column。用户提供的金额列值或自动计算。我写了一个代码。当我尝试执行它时显示错误。 Index was out of range. Must be non-negative and less than the size of the collection.Parameter name: index。我该如何解决？

对齐::

以下是代码：

        private void dgvSalesFooterAdd_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e)
        {
            decimal Total = 0;

            decimal a=Convert.ToDecimal(lblTotalAdd.Text);
            for (int i = 0; i <dgvSalesFooterAdd.Rows.Count ; i++)
            {

                dgvSalesFooterAdd.Rows[i].Cells[4].Value = a + (a * (Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[3].Value)/100));

                Total += Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[4].Value);
            }
            lblFinalTotalAdd.Text = Total.ToString();
        }

[注意：错误

dgvSalesFooterAdd.Rows[i].Cells[4].Value = a + (a * (Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[3].Value)/100));
Total += Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[4].Value); 

这两个lins。]

Answer 1

在i中找不到Row索引时抛出异常。您必须将行数减少1.这将告诉循环仅计算由值填充的行。改变行

int i = 0; i <dgvSalesFooterAdd.Rows.Count

到

int i = 0; i <dgvSalesFooterAdd.Rows.Count - 1

完整区块将如下所示;

        for (int i = 0; i <dgvSalesFooterAdd.Rows.Count - 1; i++)
        {

            dgvSalesFooterAdd.Rows[i].Cells[4].Value = a + (a * (Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[3].Value)/100));

            Total += Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[4].Value);
        }

Answer 2

  dgvSalesFooterAdd.Rows[i].Cells[4].Value = a + (a *(Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[3].Value)/100));
Total += Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[4].Value); 

它会抛出异常，因为你正在读取第4列的值为null，因为一旦离开单元格，cell_value就会改变...

通过这个链接，它会给你一个更好的图片.. http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.cellvaluechanged.aspx

并试试这样的代码..

 void dgvSalesFooterAdd_CurrentCellDirtyStateChanged(object sender,
EventArgs e)
 {
if (dgvSalesFooterAdd.IsCurrentCellDirty)
{
    dgvSalesFooterAdd.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
}

  private void dgvSalesFooterAdd_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e)
    {
        decimal Total = 0;

        decimal a=Convert.ToDecimal(lblTotalAdd.Text);
        for (int i = 0; i <dgvSalesFooterAdd.Rows.Count ; i++)
        {

            dgvSalesFooterAdd.Rows[i].Cells[4].Value = a + (a * (Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[3].Value)/100));

            Total += Convert.ToDecimal(dgvSalesFooterAdd.Rows[i].Cells[4].Value);
        }
        lblFinalTotalAdd.Text = Total.ToString();
    }