vb.net-检查Datagridview中是否有重复数据 [英] vb.net - check if there are duplicate data in Datagridview

问题描述

如何检查datagridview中是否存在重复项？

How do I check if there are duplicate in datagridview?

我有以下代码：

For x As Integer = 0 To DataGridView1.Rows.Count - 1
    For y As Integer = x + 1 To DataGridView1.Rows.Count - 1
        If DataGridView1.Rows(x).Cells(0).Value.ToString = DataGridView1.Rows(y).Cells(0).Value.ToString Then
            MsgBox("Duplicate Data!")
            Exit Sub
        Else
            save_data()
            Me.Close()
        End If
    Next
Next

如果重复数据像下面这样互相重复，则上面的代码可以：

the code above is okay if the duplicate data is following each other like this:

Column1 (cell 0)  |  Column2 (cell 1)
------------------|------------------
TEST              |  NAME
TEST              |  NAME2

和重复数据！出现消息框。

and the "Duplicate Data!" Message Box appears.

但是，当重复的数据不互相跟踪时，它将转到 else 语句，其中它将被保存。像这样：

But when the duplicate data is not following each other it will go to the else statement where it will be saved. Like this:

Column1 (cell 0)  |  Column2 (cell 1)
------------------|------------------
TEST              |  NAME
TEST2             |  NAME3
TEST              |  NAME2

，数据将被保存。如 else 语句中所示。

and the data will be saved. as shown in the else statement.

我应该怎么做，即使重复的数据不在每个后面其他 MsgBox（重复数据！）仍然出现吗？

What should I do so that even if the duplicate data are not following each other the MsgBox("Duplicate Data!") still appears?

推荐答案

在第二个For循环中，您应检查除第一个循环所处的索引以外的所有行，而不是索引+1。此外，如前所述，请清理else语句，因为它将阻止检查整个网格。如果找不到重复项，请在循环结束时调用您的Save_Data。

In your second For Loop you should check ALL rows other than the index you're on with the first loop, instead of index + 1. Also as mentioned, clean up that else statement because it will prevent the whole grid from being checked. Call your Save_Data at the end of looping if no duplicates were found. Use a Boolean to keep track.

Dim bolDuplicateWasFound As Boolean = False

For x As Integer = 0 To DataGridView1.Rows.Count - 1
    For y As Integer = 0 To DataGridView1.Rows.Count - 1
        If y <> x AndAlso DataGridView1.Rows(x).Cells(0).Value.ToString = DataGridView1.Rows(y).Cells(0).Value.ToString Then
            bolDuplicateWasFound = True
            MsgBox("Duplicate Data!")
            Exit Sub
        End If
    Next
Next

If Not bolDuplicateWasFound Then
    Save_Data()
End If

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