Question

我有一个组合框，用于填充来自数据库的数据。我想要默认文本首次加载页面时，“请选择”显示在组合框中，重置时必须位于顶部。只打开组合框时出现默认文本。请帮忙

这是我如何绑定我的组合框;

    private void LoadCombo()
    {
        try
        {
            oConnection = new SqlConnection(_connectionString);
            oCommand = new SqlCommand("select * from tbldpt", oConnection);
            oAdapter = new SqlDataAdapter(oCommand);
            oConnection.Open();
            oDataset = new System.Data.DataSet();
            SqlDataReader oReader = oCommand.ExecuteReader();

            while (oReader.Read())
            {                   
                string _Combobox = oReader["Name"].ToString();
                cboDepartment.Items.Add(_Combobox);
            }
            cboDepartment.Items.Insert(0, "--Select Department--");
            oReader.Close();
            oConnection.Close();
        }
        catch(Exception ex)
        {
        }

    }

Answer 1

试试这个代码段，

cboDepartment.Items.Add("--Select Department--");
 while (oReader.Read())
  {                   
    string _Combobox = oReader["Name"].ToString();
    cboDepartment.Items.Add(_Combobox);
  }
  cboDepartment.selectedIndex=0;

Answer 2

创建字符串列表并使用组合框绑定。

try
        {
            oConnection = new SqlConnection(_connectionString);
            oCommand = new SqlCommand("select * from tbldpt", oConnection);
            oConnection.Open();
            oDataset = new System.Data.DataSet();
            SqlDataReader oReader = oCommand.ExecuteReader();

            list<string> _combobox=new list<string>();
            _combobox.add("--Select Department--");

            while (oReader.Read())
            {                   
                _combobox.Add(oReader["Name"].ToString());

            }
cboDepartment.Datasource=_combobox

            oReader.Close();
            oConnection.Close();
        }
        catch(Exception ex)
        {
        }

使用Reader将组合框与默认文本绑定

2 个答案: