Do it after DATAGRIDVIEW in binding data statistics-CodePudding

I am then sum by filling in the data, but do not know why now sum the result is 0,

 
String sql_str="SELECT online distribution order result table. Order industry as a result, online distribution order result table. KuoXiao amount as a result, online distribution order result table. The order number" + 
"FROM the online distribution order result table INNER JOIN megabite dimension result table name list ON the online distribution order. Order megabite results=megabite dimension names table. Dimensions industry" + 
Name of "UNION ALL SELECT supermarket stores, supermarkets KuoXiao amount, supermarket order number FROM the online distribution order table supermarket results"; 

CMD=new OleDbCommand (sql_str, conn); 
Conn. The Open (); 
Find_do=new OleDbDataAdapter (); 
Find_do. SelectCommand=CMD; 
Ds=new DataSet (); 
Find_do. The Fill (ds, "rs"); 
Conn. Close (); 
DataTable DataTable=ds. The Tables (" rs "); 
Int ab=0; 
DataGridViewRowCollection rows=this. D_xs2. Rows; 

Foreach (DataGridViewRow row in rows) 
{
Ab +=the Convert. ToInt32 (row) Cells [1]. The Value). 
} 

DataRow dataRows. 
DataRows=dataTable. NewRow (); 
DataRows [0]="combined"; 
DataRows [1]=ab; 
The dataTable. Rows. The Add (dataRows); 
Enclosing d_xs2. The DataSource=dataTable;