填充组合框从SQL在C＃

Question

我试图从SQL填充我组合框但是当我的值成员分配给它，它给了我下面的错误

cannot explicitly convert int into string 

你能帮助我理解并纠正我的错误？

void Fillcombo() 
    { 
     string query_select = "SELECT * FROM department"; 
     DataTable dt = DataAccess.selectData(query_select); 
     SqlDataReader dr = DataAccess.selectDataReader(query_select); 
     while (dr.Read()) 
      { 
       string dpt_name = dr.GetString(1); 
       int dpt_id = (int)dr.GetValue(0); 
       comboBox1.DataSource = dt; 
       comboBox1.ValueMember = dpt_id; // error here 
       comboBox1.DisplayMember = dpt_name; 

      } 
    } 

Answer 1

您必须DataSource（DataTable）到ValueMenmber和DisplayMember作为字符串指定列的名称，你不需要使用while循环，如下所示：

void Fillcombo() 
{ 
    string query_select = "SELECT * FROM department"; 
    DataTable dt = DataAccess.selectData(query_select); 
    comboBox1.DataSource = dt; 
    comboBox1.ValueMember = "ColumnName_DepartmentID"; 
    comboBox1.DisplayMember = "ColumnName_DepartmentName"; 
} 

Answer 2

你应该把它写以字符串格式：

comboBox1.ValueMember = "dpt_id";