CODEWITHSUNDEEP
c#sql-serverpoint
Mike91
Mike91

Reputation: 540

Creating an array of points from SQL Server database c#

I am quite new to c# and have stored positions of an object in a SQL Server database. I have written a query to select the object locations out of the database and now want to populate an array with these.

I have had trouble with 'you cannot convert an object to a point' etc errors and I cannot figure out how to populate an array with the point data type.

Could anyone help me with this?

Current code: 

 try
 {
    consecond.Open(); //Opens the connection
    SqlDataReader dr = com_getposition.ExecuteReader();
    int i = 0;
    object[] arrayreturn = new object[10];
    while (dr.Read())
    {
        arrayreturn[i] = dr["POSITION"];
        i++;
    }
    p1.Location = (Point)arrayreturn[0];
    dr.Close();
 }
 finally
 {
     consecond.Close(); //Closes the connection
 }

Thanks

Upvotes: 0

Views: 503

Answers (2)

Magnus
Magnus

Reputation: 46937

If POSITION is of type nvarchar you need to parse it (not cast it) into correct type.

var str = (string)dr["POSITION"];
var i = str.IndexOf(',', 3);
var x = int.Parse(str.Substring(3, i  - 3));
var y = int.Parse(str.Substring(i + 3, str.Length - (i + 4)));
p1.Location = new Point(x, y);

Upvotes: 1

egrunin
egrunin

Reputation: 25053

Magnus is correct, but personally I prefer something like this:

Int32 n;
bool b = Int32.TryParse(arrayreturn[0].ToString(), out n);
if (b)
    p1.Location = n;

If location is a Point, then you can modify this:

Int32 x;
Int32 y;

bool b = Int32.TryParse(arrayreturn[0].ToString(), out x);
if (b) {
    b = Int32.TryParse(arrayreturn[1].ToString(), out y);
    if (b) {
        p1.Location = new Point(x, y);
        return;
    }
}

// put error-handling code here

Upvotes: 0

Related Questions