c# - 填: SelectCommand. 连接属性还没有初始化

Question

在使用网站、加载内容等一段时间后，此消息显示“Fill:SelectCommand.Connection 属性尚未初始化”!我认为这是因为 sql 连接，但不确定......我想知道我能做些什么来防止这种情况，每次发生这种情况我都必须上传一个文件(SQL 类，建立连接)和网站又开始工作了。

我的 SQL 连接:

public class SQL
{

    SqlCommand comandos;
    public SqlConnection sql()
    {
        string Server = @"server"; 
        string Username = "user"; 
        string Password = "pass"; 
        string Database = "database";
        string ConnectionString = "Data Source=" + Server + ";";
        ConnectionString += "User ID=" + Username + ";";
        ConnectionString += "Password=" + Password + ";";
        ConnectionString += "Initial Catalog=" + Database;

        SqlConnection Connection = new SqlConnection();
        try
        {
            Connection.ConnectionString = ConnectionString;
            Connection.Open();
            return Connection;
        }
        catch (Exception)
        {
            if (Connection != null)
            {
                Connection.Dispose();
        }
        return null;
        }
    }

    public void FazerComando(string comando)
    {
        comandos = new SqlCommand(comando, sql());
        comandos.ExecuteNonQuery();
    }

    public DataTable Execute(string comando)
    {
        SqlDataAdapter SQLDataAdapter = new SqlDataAdapter(comando, sql());
        DataTable dtResult = new DataTable();
        SQLDataAdapter.Fill(dtResult);
        return dtResult;
    }
}

Answer 1

这可能与您的问题有关，但无论如何，这是应该解决的问题:当您完成连接后，您并没有丢弃它们。你应该使用 using:

    public void FazerComando(string comando)
    {
        using (var conn = sql())
        {
            comandos = new SqlCommand(comando, conn);
            comandos.ExecuteNonQuery();
        }
    }
    public DataTable Execute(string comando)
    {
        using (var conn = sql())
        {
            SqlDataAdapter SQLDataAdapter = new SqlDataAdapter(comando, conn);
            DataTable dtResult = new DataTable();
            SQLDataAdapter.Fill(dtResult);
            return dtResult;
        }
    }