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使用块中的OleDbCommand:COM对象已与其底层RCW分离,无法使用

comobject using exception database c#

MiOnIs · 技术社区 · 9 年前

OleDbCommand 中的对象 using parameters

using (OleDbCommand comm = new OleDbCommand())
        {
            comm.Connection = conn;
            comm.CommandType = CommandType.Text;
            string txt = "SELECT* FROM [ListForGroup] WHERE [email] = @email";
            comm.Parameters.Add("@email", OleDbType.VarWChar).Value = userEmail;
            comm.CommandText = txt;
            conn.Open();
            OleDbDataReader reader = comm.ExecuteReader();
            List<ListForGroups> list = returnLists(reader);
            conn.Close();
            cmbSelectList.DataSource = list;
            cmbSelectList.DisplayMember = "listName";
            cmbSelectList.ValueMember = "listForGroupsID";
        }

有人知道原因吗。我可以将其解析为使用 OLEDB命令 具有的对象 CommandText 但我读到这是个坏主意。我想在 使用

1 回复 | 直到 9 年前

MiOnIs 9 年前

我解决了这个问题

using (OleDbConnection conn = new OleDbConnection(connString))
    {
        OleDbCommand comm = new OleDbCommand();
        comm.Connection = conn;
        comm.CommandType = CommandType.Text;
        string txt = "SELECT* FROM [ListForGroup] WHERE [email] = @email";
        comm.Parameters.Add("@email", OleDbType.VarWChar).Value = userEmail;
        comm.CommandText = txt;
        conn.Open();
        OleDbDataReader reader = comm.ExecuteReader();
        List<ListForGroups> list = returnLists(reader);

        cmbSelectList.DataSource = list;
        cmbSelectList.DisplayMember = "listName";
        cmbSelectList.ValueMember = "listForGroupsID";
    }

OleDbConnection 在旁边的括号中 using connection 之后