Question

我有一个函数，它填充下拉列表并设置BindingSource中的显示和值成员，但我不知道如何只选择所选项的值。

Dictionary bindingsource population：

    public Dictionary<int, string> Get_List_of_ManualSchemes()
    {
        Dictionary<int, string> comboSource = new Dictionary<int, string>();

        using (SqlConnection cnn = new SqlConnection(connectionString))
        {
            cnn.Open();
            string query = "SELECT [idGMRScheme],[SchemeName] FROM [DBA_Admin].[dbo].[GMR_Schemes]";

            using (SqlCommand command = new SqlCommand(query, cnn))
            using (SqlDataReader reader = command.ExecuteReader())
                while (reader.Read())
                {
                    comboSource.Add((int)reader["idGMRScheme"], (string)reader["SchemeName"]);
                }
        }
        return comboSource;
    }

用它填充组合：

        public void Populate_ManualSchemes_Combolist(Dictionary<int, string> comboSource)
        {
            cb_SchemesManual.DataSource = new BindingSource(comboSource, null);
            cb_SchemesManual.ValueMember = "value";
            cb_SchemesManual.DisplayMember = "text";
        }

我尝试着：

cb_ManualSchemes.SelectedValue

并返回显示的文本，而不是id，当我尝试时：

cb_ManualSchemes.SelectedText

它什么都不返回

Answer 1

因为您使用的字典是键值对的集合。显示成员和值成员必须与字典中项目的属性匹配

尝试以下

 cb_SchemesManual.ValueMember = "Key";
 cb_SchemesManual.DisplayMember = "Value";

Answer 2

使用以下代码对您的组合框进行外壳，以便您可以使用cb_ManualSchemes.SelectedValue

访问该值

  public void Populate_ManualSchemes_Combolist(Dictionary<int, string> comboSource)
    {
      cb_SchemesManual.DataSource=comboSource;
       cb_SchemesManual.ValueMember = "Key";
       cb_SchemesManual.DisplayMember = "Value";
    }

Answer 3

尝试使用DataTable for comboSource而不是Dictionary。

public DataTable Get_List_of_ManualSchemes()
    {
        DataTable comboSource = new DataTable();
        comboSource.Columns.Add("value", typeof(Int32));
        comboSource.Columns.Add("text");
        DataRow newRow;

        using (SqlConnection cnn = new SqlConnection(connectionString))
        {
            cnn.Open();
            string query = "SELECT [idGMRScheme],[SchemeName] FROM [DBA_Admin].[dbo].[GMR_Schemes]";

            using (SqlCommand command = new SqlCommand(query, cnn))
            using (SqlDataReader reader = command.ExecuteReader())
                while (reader.Read())
                {
                    newRow = comboSource.NewRow();
                    newRow["value"] = (Int32)reader["idGMRScheme"];
                    newRow["text"] = reader["SchemeName"].ToString();
                    comboSource.Rows.Add(newRow);
                }
        }
        return comboSource;
    }

    public void Populate_ManualSchemes_Combolist(DataTable comboSource)
    {
        cb_SchemesManual.DataSource = comboSource;
        cb_SchemesManual.ValueMember = "value";
        cb_SchemesManual.DisplayMember = "text";

    }

如何选择当前所选项目的DisplayMember或DisplayValue？

3 个答案: