from datatable to array، no loop
Following Code for transmission to the list box is :
DataTable dt = new DataTable();
DataColumn dc = new DataColumn("BestSite", typeof(string));
dt.Columns.Add(dc);
开发者_开发问答 for (int i = 1; i <= 10; i++)
{
DataRow dr = dt.NewRow();
dr[0] = i.ToString() + " = stackoverflow";
dt.Rows.Add(dr);
}//EndFor
var Query = from mycolumn in dt.AsEnumerable()
where mycolumn.Field<string>("BestSite") != string.Empty
select mycolumn;
listBox1.DataSource = Query.AsDataView();
listBox1.DisplayMember = "BestSite";
Transfer to array what should be? no loop
string[] myvalue = new string[Query.AsDataView().Count];
Finally realized
Correct answer :
private string ConvertToString(DataRow dr)
{
return Convert.ToString(dr[0]);
}
private void button1_Click(object sender, EventArgs e)
{
DataTable dt = new DataTable();
DataColumn dc = new DataColumn("BestSite", typeof(string));
dt.Columns.Add(dc);
for (int i = 1; i <= 10; i++)
{
DataRow dr = dt.NewRow();
dr[0] = i.ToString() + " = stackoverflow";
dt.Rows.Add(dr);
}//EndFor
//var Query = from mycolumn in dt.AsEnumerable()
// where mycolumn.Field<string>("BestSite") != string.Empty
// select mycolumn;
DataRow[] myrow = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(myrow, 0);
string[] myString = Array.ConvertAll(myrow, new Converter<DataRow, string>(ConvertToString));
foreach (string a in myString)
{
listBox1.Items.Add(a);
}
}
If I understood your question correctly...
string[] myvalue = Query.Select(i => i.Field<string>("BestSite")).ToArray();
This example assumes:
=> datatable is non zero length
=> values are "parsable" to double.
coln = "PurchasePrice";
double[] arr_val = Array.ConvertAll<DataRow, double>
(
dattbl.Select(),
delegate (DataRow rw) { return
double.Parse(rw[coln].ToString()); }
);
// ... and for example
double total = arr_val.Sum();
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