总和DataGridView C＃

Question

我想显示标签一列的所有单元格的 sum 的重新填充。我尝试了一个在网络中看到的代码，但代码不起作用。

这是代码：

foreach (DataGridViewRow row in dgv_Carrinho.Rows.Cast<DataGridViewRow>().Where(t => !string.IsNullOrEmpty(t.Cells["Valor"].Value?.ToString())))
            {
                lbl_Subtotal.Text += (Convert.ToDouble(row.Cells["Valor"].Value)).ToString();
            }

有人可以帮我吗？

Answer 1

您必须先计算总和，然后将其分配给lbl_subtotal.text，就像

var sum = 0;
foreach (DataGridViewRow row in dgv_Carrinho.Rows.Cast<DataGridViewRow>().Where(t => !string.IsNullOrEmpty(t.Cells["Valor"].Value?.ToString())))
    sum += (Convert.ToDouble(row.Cells["Valor"].Value));

//Now assign it to label
 lbl_Subtotal.Text = sum.ToString();

---

让我们尝试一些Linq操作一样，

var sum = dgv_Carrinho.Rows.Cast<DataGridViewRow>()
     .Select(double.TryParse(row.Cells["Valor"].Value?.ToString(), out double value) ? value : 0)
     .Sum();
//Now assign it to label
lbl_Subtotal.Text = sum.ToString();

Answer 2

var count = 0;
foreach (DataGridViewRow row in dgv_Carrinho.Rows.Cast<DataGridViewRow>().Where(t => !string.IsNullOrEmpty(t.Cells["Valor"].Value?.ToString())))
{
     count += (Convert.ToDouble(row.Cells["Valor"].Value)).ToString();
}
lbl_Subtotal.Text = count.ToSring();

Answer 3

您可以为DataGridView使用添加扩展功能

public double getSumCell(this DataGridView GridView, string ColName)
{
    double sumValue = (from d in GridView.Rows
                       select d).Sum(DataGridViewRow x => Convert.ToDouble(x.Cells(ColName).Value));

    return sumValue;
}

：

lbl_Subtotal.Text = dgv_Carrinho.getSumCell("COLUMN_NAME");