Question

我有这样的东西：

Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
    Dim dt As New DataTable()
    AppendColumnsToDGV2(dt)
    For Each row As DataGridViewRow In DataGridView1.Rows
        If row.Cells("SelectColumn").Value = True Then
            Dim NewRow = dt.NewRow
            For i As Integer = 0 To row.Cells.Count - 1
                NewRow(i) = row.Cells(i).Value
            Next
            dt.Rows.Add(NewRow)
        End If
    Next
End Sub

Private Sub AppendColumnsToDGV2(dt As DataTable)
    'dt.Columns.Add(CreateDGVCheckBoxCol())
    'dt.Columns.Add(CreateImageColumn())
    dt.Columns.Add(DataGridView1.Columns(3).HeaderText)
    dt.Columns.Add(DataGridView1.Columns(4).HeaderText)
    dt.Columns.Add(DataGridView1.Columns(5).HeaderText)
    dt.Columns.Add(DataGridView1.Columns(6).HeaderText)
    DataGridView2.DataSource = dt
End Sub

和基础类型是这样的：

x1 := someFunctionWithAnInterfaceReturnValue()

我将如何访问x1中的值？

本质上来说，我希望与x1等效：

x2 := map[string] string{"hello": "world"}

Answer 1

使用type assertion：

x1 := someFunctionWithAnInterfaceReturnValue()
x2, ok := x1.(map[string]string)
if !ok {
   // handle unexpected type
}
var value string = x2["hello"]

如何从使用interface {}输入的golang map [string]字符串中提取值

1 个答案: