c# - Showing Database Search results in Datagridview -

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i using visual studio 2013 sql server 2012 database in windows forms application c#.

i want show query search results in datagridview:

public void customersearch(int custid, datagridview datagridview) {         try         {             sqlconnection connection = new sqlconnection(@"connection string");             connection.open();              sqlcommand searchquery = new sqlcommand("select * [customer] custid = @custid", connection);             searchquery.parameters.addwithvalue("@custid", custid);             //searchquery.executenonquery();              using (sqldatareader reader = searchquery.executereader())             {                 while (reader.read())                 {                     datagridview.databindings.tostring();                 }             }         }         catch (sqlexception exception)         {             messagebox.show(exception.tostring());         }                 {             connection.close();         }     } }

i got nullreferenceexception @ connection.close(); appreciated.

when put connection in using automatically close , dispose connection when block exits.

public void customersearch(int custid, datagridview datagridview)         {             using (sqlconnection connection = new sqlconnection(configurationmanager.connectionstrings["myconnectionstring"].connectionstring))             {                 try                 {                      connection.open();                      sqlcommand searchquery = new sqlcommand("select * [customer] custid = @custid", connection);                     searchquery.parameters.add("@custid", sqldbtype.int).value = custid;                     //searchquery.executenonquery();                      using (sqldatareader reader = searchquery.executereader())                     {                         datatable dt = new datatable();                         dt.load(reader);                         datagridview.autogeneratecolumns = true;                         datagridview.datasource = dt;                         datagridview.refresh();                     }                 }                 catch (sqlexception exception)                 {                     messagebox.show(exception.tostring());                 }             }         }

--edit--

you can't bind datagridview datareader. edited code above demonstrate 1 way this. create datatable reader , bind grid datatable.


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