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即时消息工作来显示我的数据网格中的数据,并显示文本框2中带来的项目总数,但是此错误“运算符'+'不是为'Decimal'类型定义并键入'DBNull'。“问题是什么?请帮助我,我需要完成这个如此糟糕。 。:(运算符'+'没有为'Decimal'类型定义,而输入'DBNull'
Private Sub dailySales_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
con.Connect()
DataGridView1.DataSource = dtb
dtb.Columns.Add("Transaction Code")
dtb.Columns.Add("Transaction Date ")
dtb.Columns.Add("Item Code")
dtb.Columns.Add("Item")
dtb.Columns.Add("Description")
dtb.Columns.Add("Quantity")
dtb.Columns.Add("Price")
dtb.Columns.Add("Total")
display()
con.Close()
total()
TextBox1.Text = DataGridView1.RowCount()
Me.DataGridView1.DefaultCellStyle.Font = New Font("Cambria", 10)
Me.DataGridView1.ColumnHeadersDefaultCellStyle.Font = New Font("Cambria", 12)
Me.DataGridView1.DefaultCellStyle.SelectionBackColor = Color.FromArgb(129, 207, 224)
Dim i As Integer
For i = 0 To DataGridView1.Columns.Count - 1
DataGridView1.Columns.Item(i).SortMode = DataGridViewColumnSortMode.Programmatic
Next
End Sub
Sub total()
Dim sum As Decimal = 0
For x = 0 To DataGridView1.Rows.Count - 1
sum =sum + DataGridView1.Rows(x).Cells(7).Value
Next
TextBox2.Text = sum
End Sub
Sub display()
con.Connect()
Label6.Text = Date.Now.ToString("dd MMMM yyyy")
Dim da = Label6.Text
Dim sc = " where lower(tns_date) like lower('%" & da & "%') "
Dim sql = "select * from tns " & sc & " order by tns_code desc"
odr = con.Retrieve(sql)
dtb.Clear()
While (odr.Read)
Dim ic = odr.GetOracleValue(0)
Dim itn = odr.GetOracleValue(1)
Dim de = odr.GetOracleValue(2)
Dim ca = odr.GetOracleValue(3)
Dim pr = odr.GetOracleValue(4)
Dim st = odr.GetOracleValue(5)
Dim sst = odr.GetOracleValue(6)
dtb.Rows.Add(ic, itn, de, ca, pr, st, sst)
End While
con.Close()
End Sub
一列7个值是零当然,你可以测试为,而不是做加法;或修改查询(你还没有表现出)使用'nvl()'或'coalesce()'返回零而不是空值? –
@AlexPoole在我的列中没有null.how做测试? –
或测试IsDBnull(DataGridView1.Rows(x).Cells 7).Value),如果为true,则跳过 –