vb.net中datagridview列的查找和求和值

我想使用此代码在数据网格视图列am中查找和求和搜索id的数量值

Dim tqty As Double
For Each row As DataGridViewRow In dgv.Rows
    If row.Cells.Item(0).Value = cmbItemCode.Text Then
        tqty += row.Cells.Item(4).Value
        Textbox1.text=tqty
        Exit For
    End If
Next

问题是

Textbox1

只显示一个顶部搜索的行值。比如说

id     item name    qty
1      abc           4
2      xyz           10
1      abc           10

---

Textbox1

仅显示结果4。

只要您点击第一个值，就退出for语句。因此，您永远无法通过第一个值。清除出口，因为它应该可以工作。

如果DataGridView2.RowCount>1，则 Dim tqty作为整数=0

        'if you have the other column to get the result you  could add a new one like these above 
        For index As Integer = 0 To DataGridView2.RowCount - 1
            amount += Convert.ToInt32(DataGridView2.Rows(index).Cells(2).Value)

            'if you have the other column to get the result you  could add a new one like these above (just change Cells(2) to the one you added)
        Next
        TextBox1.Text = tqty

---

他还应该等待设置

TextBox1.Text

，直到循环结束。