How to Convert string to Arraylist type

[Brian Connelly]

I am receiving a Cannot implicitly convert type "String" to"System.Collections.ArrayList". I new to programming so trouble shooting is an issue for me and if someone could help would be much appreciated. I highlighted the section returning the error with bold type font. Here is my code:

public partial class MassMailer : System.Web.UI.Page
{
    static string CSTR = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" +
       AppDomain.CurrentDomain.BaseDirectory + "SuCasaVersion8.mdb";
 
    int associationID;
    ArrayList massEmail;
    string buildStName;
 
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            populateBuildingDropDown();
    }
 
    protected void populateBuildingDropDown()
    {
 
        string query = "SELECT * FROM Association";
        System.Data.OleDb.OleDbCommand ocmd = new System.Data.OleDb.OleDbCommand(query, new System.Data.OleDb.OleDbConnection(CSTR));
        ocmd.Connection.Open();
        System.Data.OleDb.OleDbDataReader dr = ocmd.ExecuteReader();
        dropBuildingList.Items.Clear();
        while(dr.Read())
        {
            string buildingName = dr.GetString(3);
            string buildingID = dr.GetInt32(0).ToString();
 
            dropBuildingList.Items.Add(new ListItem(buildingID + ": " + buildingName, buildingID));
        }
        ocmd.Connection.Close();
        dropBuildingList.AutoPostBack = true;
    }
    protected void dropBuildingList_SelectedIndexChanged(object sender, EventArgs e)
    {
        massEmail.Clear();
        associationID = Convert.ToInt32(dropBuildingList.SelectedValue);
        string query = "SELECT Email(1) FROM Occupant INNER JOIN Association INNER JOIN Association-Occupant ON"+ 
        "Association.PropertyID = Association-Occupant.Property ID ON Occupant.Occupant ID = Association-Occupant.Occupant ID"+
        "WHERE Association.AssociationID=@associationID GROUP BY Email(1)";
 
        System.Data.OleDb.OleDbCommand ocmd = new System.Data.OleDb.OleDbCommand(query, new System.Data.OleDb.OleDbConnection(CSTR));
        ocmd.Parameters.AddWithValue("@associationID", associationID);
        ocmd.Connection.Open();
        System.Data.OleDb.OleDbDataReader dr = ocmd.ExecuteReader();
        while (dr.Read())
        {
            massEmail = dr.GetString(8).ToString();
        }
        ocmd.Connection.Close();
        dropBuildingList.AutoPostBack = true;
 
 
    }
}
 

[GaryTexmo]

It's exactly what the error says. massEmail is of type ArrayList and you're trying to assign a string to it.

I believe you want to use the Add method to add it to the list instead of assigning it.

http://msdn.microsoft.com/en-us/libr...=VS.71%29.aspx

The other possibility is to just make massEmail a string type instead of an ArrayList, but I don't know the details of what you're trying to do.

[Brian Connelly]

I have created a query that returns multiple email addresses. I would like to place each row into an ArrayList, but am having trouble and have spent the last two hours working on it. Can you help explain and show me how to do it? My query and code is follows:

massEmail=new ArrayList();
associationID = Convert.ToInt16(dropBuildingList.SelectedValue);
 
string query = " SELECT Occupant.[Email(1)]FROM Occupant INNER JOIN"+
"(Association INNER JOIN [Association-Occupant] ON Association.PropertyID "+ 
"= [Association-Occupant].PropertyID) ON Occupant.OccupantID = [Association-Occupant].OccupantID"+
" WHERE (((Association.AssociationID)=@associationID))GROUP BY Occupant.[Email(1)]";
 
        System.Data.OleDb.OleDbCommand ocmd = new System.Data.OleDb.OleDbCommand(query, new System.Data.OleDb.OleDbConnection(CSTR));
        ocmd.Parameters.AddWithValue("@associationID",associationID);
        ocmd.Connection.Open();
        System.Data.OleDb.OleDbDataReader dr = ocmd.ExecuteReader();
 

[GaryTexmo]

It looks like the result of your query is going to be a list of e-mail addresses, is that correct? I don't use these commands that often but I believe you can have a query return a data set.

At that point, you can just loop through the rows returned in the dataset and add them to the ArrayList.

Also, this seems to be roughly the same question as the other one you posted... http://bytes.com/topic/c-sharp/answe...arraylist-type. Please refrain from posting new threads on the same issue, it's generally better to keep everything in the same thread so it's easier to follow the progression of the discussion.

Thanks!