I have a code that reads the information from the database and assigns it to the list
class YaziciBilgiler
{
public string yaziciAdi;
public List<YaziciBilgiler> YaziciSec()
{
con.Open();
OracleCommand cmd = new OracleCommand("SELECT PRINTER_NAME FROM LABEL_PRINTER ");
DataSet dataset = new DataSet();
cmd.Connection = con;
cmd.CommandType = CommandType.Text;
using (OracleDataAdapter dataAdapter = new OracleDataAdapter())
{
dataAdapter.SelectCommand = cmd;
dataAdapter.Fill(dataset);
}
var yazici=dataset.Tables[0].AsEnumerable().Select(datarow=>new YaziciBilgiler
{
yaziciAdi = datarow.Field<string>("PRINTER_NAME")
}).ToList();
con.Close();
return yazici;
}
}
}
Then call the information in the printer list from the form
List<YaziciBilgiler>yazici;
yazici=yb.YaziciSec();
foreach (var item in yazici)
{
cbYazici.Items.Add(item);
}
but instead of the contents of the list, the location is as follows:
The basic problem with your code is that you have created a list full of objects with type YaziciBilgiler with a single string member called yaziciAdi
Combo doesn't know how to display this, it doesn't know to get the yaziciAdi property and show it, and you haven't told it so the only thing it can do when faced with an unknown object is call ToString() on it to get a string and display that string
Because you haven't overridden ToString it performs its default action which is to report the name of the class. This means your combo is full of repeated words of YaziciBilgiler
You have a few options:
override ToString so that it returns the yaziciAdi property
make your code that adds the items inside the loop add the yaziciAdi property instead of the whole object: cbYazici.Items.Add(item.yaziciAdi);
change the yaziciAdi member to be a property instead. bind the combobox to the list, or to the datatable- the discussion for this is in the comments to the question. I don't use WPF but reading around, I think the code might be something like:
cbYazici.SetBinding(
ItemsControl.ItemsSourceProperty,
new Binding { Source = yazici });
cbYazici.DisplayMemberPath = "yaziciAdi";
Or use an equivalent in the XAML (if the codebehind can't set these; I've no idea whether it can or not, and any experienced WPF guys feel free to edit this answer if I've got this wrong)
Note: to bind property yaziciAdi MUST be a property, not a field
You can try this :
cbYazici.Items.Add(item.yaziciAdi)
I am trying to create a DataRow which gets some values from hard-coded strings or string variables, and the rest of the values from a collection's values, System.Collections.Generic.Dictionary<string, double>.ValueCollection to be specific. In my attempt below, I'm casting to an array but that doesn't work.
DataTable source = new DataTable();
foreach (string sample in GridSource.SampleName)
{
SampleDictionaries sd = GridSource.Data.Where(x => GridSource.Data.IndexOf(x) == GridSource.SampleName.IndexOf(sample)).First();
source.Rows.Add(sample, "Average", sd.Avg.Values.ToArray());
source.Rows.Add("", "Std. Deviation", sd.StdDev.Values.ToArray());
}
The code above produces this:
I understand what is happening here. My question is this: is there an easy way to tell the DataRow "Fill the remaining column values with this collection," or am I going to have to come up with some loop to do it?
what you can do is create the row from the datatable.NewRow() method. Then you can have the items array of the row equal an array of data:
DataTable source = new DataTable();
foreach (string sample in GridSource.SampleName)
{
DataRow temp = source.NewRow();
SampleDictionaries sd = GridSource.Data.Where(x => GridSource.Data.IndexOf(x) == GridSource.SampleName.IndexOf(sample)).First();
temp.ItemArray = new object[]{sample, "Average"}.Concat(sd.Avg.Values.ToArray());
source.Rows.Add(temp);
temp = source.NewRow();
temp.ItemArray = new object[]{"", "Std. Deviation".Concat(sd.StdDev.Values.ToArray());
}
Found an answer, with help from KMoussa!
source.Rows.Add(new object[] { "", "Std. Deviation"}.Concat(sd.StdDev.Values.Cast<object>().ToArray()).ToArray());
Very similar to what he recommended, but it was missing a second cast to array at the end.
I see a lot of complex examples for converting a DataTable with multiple-member rows here but in my case, the query simply returns one column from a table, that is to say 0..N strings/varchars, such as:
bbfinaleofseem#wallacestevens.org
eyenoy#dunbar.com
I thought something like this should work:
DataTable UnitReportPairEmailValsDT = new DataTable();
string qry = string.Format(SQL.UnitReportPairEmailQuery, unit, rptId);
UnitReportPairEmailValsDT = SQL.ExecuteSQLReturnDataTable(
qry,
CommandType.Text,
null
);
List<String> emailAddresses = new List<string>();
foreach (string emailaddr in UnitReportPairEmailValsDT)
{
emailAddresses.Add(emailaddr);
}
...but it won't compile ("foreach statement cannot operate on variables of type 'System.Data.DataTable' because 'System.Data.DataTable' does not contain a public definition for 'GetEnumerator'")
I tried appending ".AsEnumerable" to "in UnitReportPairEmailValsDT" too, but that also provoked the wrath of the compiler.
Error says you cannot loop through DataTable object itself, probably what you need is looping through DataRows.
Use this.
foreach(DataRow row in UnitReportPairEmailValsDT.Rows)
{
emailAddresses.Add(row["emailaddr"].ToString()); // assuming you have emailaddr column.
}
Other option, use Linq
emailAddresses = UnitReportPairEmailValsDT
.AsEnumerable()
.Select(row=> row.Field<string>("emailaddr"))
.ToList();
try something like this:
List<String> emailAddresses = new List<string>();
foreach (DataRow row in UnitReportPairEmailValsDT.Rows)
{
emailAddresses.Add(row.Item(0));
}
Suppose dt is your data table then using Linq:
dt.Rows.Select(x=> x[0]+"").ToList() will give you List. Beware of using Select(x=>xToString()) as it is prone to error if column value is null. x[0]+"" makes sure that in case of null empty string is returned.
I'm curious as to the best route (more looking towards simplicity, not speed or efficiency) to sort a DropDownList in C#/ASP.NET - I've looked at a few recommendations but they aren't clicking well with me.
Edit: Folks, I do not have control over how the data comes into the DropDownList - I cannot modify the SQL.
If you get a DataTable with the data, you can create a DataView off of this and then bind the drop down list to that. Your code would look something like...
DataView dvOptions = new DataView(DataTableWithOptions);
dvOptions.Sort = "Description";
ddlOptions.DataSource = dvOptions;
ddlOptions.DataTextField = "Description";
ddlOptions.DataValueField = "Id";
ddlOptions.DataBind();
Your text field and value field options are mapped to the appropriate columnns in the data table you are receiving.
A C# solution for .NET 3.5 (needs System.Linq and System.Web.UI):
public static void ReorderAlphabetized(this DropDownList ddl)
{
List<ListItem> listCopy = new List<ListItem>();
foreach (ListItem item in ddl.Items)
listCopy.Add(item);
ddl.Items.Clear();
foreach (ListItem item in listCopy.OrderBy(item => item.Text))
ddl.Items.Add(item);
}
Call it after you've bound your dropdownlist, e.g. OnPreRender:
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
ddlMyDropDown.ReorderAlphabetized();
}
Stick it in your utility library for easy re-use.
Assuming you are running the latest version of the .Net Framework this will work:
List<string> items = GetItemsFromSomewhere();
items.Sort((x, y) => string.Compare(x, y));
DropDownListId.DataSource = items;
DropDownListId.DataBind();
DropDownList takes any IEnumerable as a DataSource.
Just sort it using LINQ.
I usually load a DropDownList with values from a database table, so the easiest way is to sort your results as desired with the ORDER BY clause of your SELECT statement, and then just iterate through the results and dump them into the DropDownList.
Take a look at the this article from CodeProject, which rearranges the content of a dropdownlist. If you are databinding, you will need to run the sorter after the data is bound to the list.
It is recommended to sort the data before databinding it to the DropDownList but in case you can not, this is how you would sort the items in the DropDownList.
First you need a comparison class
Public Class ListItemComparer
Implements IComparer(Of ListItem)
Public Function Compare(ByVal x As ListItem, ByVal y As ListItem) As Integer _
Implements IComparer(Of ListItem).Compare
Dim c As New CaseInsensitiveComparer
Return c.Compare(x.Text, y.Text)
End Function
End Class
Then you need a method that will use this Comparer to sort the DropDownList
Public Shared Sub SortDropDown(ByVal cbo As DropDownList)
Dim lstListItems As New List(Of ListItem)
For Each li As ListItem In cbo.Items
lstListItems.Add(li)
Next
lstListItems.Sort(New ListItemComparer)
cbo.Items.Clear()
cbo.Items.AddRange(lstListItems.ToArray)
End Sub
Finally, call this function with your DropDownList (after it's been databound)
SortDropDown(cboMyDropDown)
P.S. Sorry but my choice of language is VB. You can use http://converter.telerik.com/ to convert the code from VB to C#
Another option is to put the ListItems into an array and sort.
int i = 0;
string[] array = new string[items.Count];
foreach (ListItem li in dropdownlist.items)
{
array[i] = li.ToString();
i++;
}
Array.Sort(array);
dropdownlist.DataSource = array;
dropdownlist.DataBind();
I agree with sorting using ORDER BY when populating with a database query, if all you want is to sort the displayed results alphabetically. Let the database engine do the work of sorting.
However, sometimes you want some other sort order besides alphabetical. For example, you might want a logical sequence like: New, Open, In Progress, Completed, Approved, Closed. In that case, you could add a column to the database table to explicitly set the sort order. Name it something like SortOrder or DisplaySortOrder. Then, in your SQL, you'd ORDER BY the sort order field (without retrieving that field).
What kind of object are you using for databinding? Typically I use Collection<T>, List<T>, or Queue<T> (depending on circumstances). These are relatively easy to sort using a custom delegate. See MSDN documentation on the Comparison(T) delegate.
var list = ddl.Items.Cast<ListItem>().OrderBy(x => x.Text).ToList();
ddl.DataSource = list;
ddl.DataTextField = "Text";
ddl.DataValueField = "Value";
ddl.DataBind();
Try it
-------Store Procedure-----(SQL)
USE [Your Database]
GO
CRATE PROC [dbo].[GetAllDataByID]
#ID int
AS
BEGIN
SELECT * FROM Your_Table
WHERE ID=#ID
ORDER BY Your_ColumnName
END
----------Default.aspx---------
<asp:DropDownList ID="ddlYourTable" runat="server"></asp:DropDownList>
---------Default.aspx.cs-------
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
List<YourTable> table= new List<YourTable>();
YourtableRepository tableRepo = new YourtableRepository();
int conuntryInfoID=1;
table= tableRepo.GetAllDataByID(ID);
ddlYourTable.DataSource = stateInfo;
ddlYourTable.DataTextField = "Your_ColumnName";
ddlYourTable.DataValueField = "ID";
ddlYourTable.DataBind();
}
}
-------LINQ Helper Class----
public class TableRepository
{
string connstr;
public TableRepository()
{
connstr = Settings.Default.YourTableConnectionString.ToString();
}
public List<YourTable> GetAllDataByID(int ID)
{
List<YourTable> table= new List<YourTable>();
using (YourTableDBDataContext dc = new YourTableDBDataContext ())
{
table= dc.GetAllDataByID(ID).ToList();
}
return table;
}
}
I agree with the folks in sorting your data in the model before populating them to the DropDownList, so if you are populating this from a DB, it is a good thing to get them sorted already there using a simple order by clause, it will save you some cycles in the web server, and I am sure the DB will do it so much faster.
If you are populating this from another data source for example, XML file, using LINQ will be a good idea, or even any variation of Array.Sort will be good.
If your data is coming to you as a System.Data.DataTable, call the DataTable's .Select() method, passing in "" for the filterExpression and "COLUMN1 ASC" (or whatever column you want to sort by) for the sort. This will return an array of DataRow objects, sorted as specified, that you can then iterate through and dump into the DropDownList.
List<ListItem> li = new List<ListItem>();
foreach (ListItem list in DropDownList1.Items)
{
li.Add(list);
}
li.Sort((x, y) => string.Compare(x.Text, y.Text));
DropDownList1.Items.Clear();
DropDownList1.DataSource = li;
DropDownList1.DataTextField = "Text";
DropDownList1.DataValueField = "Value";
DropDownList1.DataBind();
To sort an object datasource that returns a dataset you use the Sort property of the control.
Example usage In the aspx page to sort by ascending order of ColumnName
<asp:ObjectDataSource ID="dsData" runat="server" TableName="Data"
Sort="ColumnName ASC" />
is better if you sort the Source before Binding it to DropDwonList.
but sort DropDownList.Items like this:
Dim Lista_Items = New List(Of ListItem)
For Each item As ListItem In ddl.Items
Lista_Items.Add(item)
Next
Lista_Items.Sort(Function(x, y) String.Compare(x.Text, y.Text))
ddl.Items.Clear()
ddl.Items.AddRange(Lista_Items.ToArray())
(this case i sort by a string(the item's text), it could be the suplier's name, supplier's id)
the Sort() method is for every List(of ) / List<MyType>, you can use it.
You can do it this way is simple
private void SortDDL(ref DropDownList objDDL)
{
ArrayList textList = new ArrayList();
ArrayList valueList = new ArrayList();
foreach (ListItem li in objDDL.Items)
{
textList.Add(li.Text);
}
textList.Sort();
foreach (object item in textList)
{
string value = objDDL.Items.FindByText(item.ToString()).Value;
valueList.Add(value);
}
objDDL.Items.Clear();
for(int i = 0; i < textList.Count; i++)
{
ListItem objItem = new ListItem(textList[i].ToString(), valueList[i].ToString());
objDDL.Items.Add(objItem);
}
}
And call the method this SortDDL(ref yourDropDownList);
and that's it. The data in your dropdownlist will be sorted.
see http://www.codeproject.com/Articles/20131/Sorting-Dropdown-list-in-ASP-NET-using-C#
You can use this JavaScript function:
function sortlist(mylist)
{
var lb = document.getElementById(mylist);
arrTexts = new Array();
arrValues = new Array();
arrOldTexts = new Array();
for(i=0; i<lb.length; i++)
{
arrTexts[i] = lb.options[i].text;
arrValues[i] = lb.options[i].value;
arrOldTexts[i] = lb.options[i].text;
}
arrTexts.sort();
for(i=0; i<lb.length; i++)
{
lb.options[i].text = arrTexts[i];
for(j=0; j<lb.length; j++)
{
if (arrTexts[i] == arrOldTexts[j])
{
lb.options[i].value = arrValues[j];
j = lb.length;
}
}
}
}
Try This:
/// <summary>
/// AlphabetizeDropDownList alphabetizes a given dropdown list by it's displayed text.
/// </summary>
/// <param name="dropDownList">The drop down list you wish to modify.</param>
/// <remarks></remarks>
private void AlphabetizeDropDownList(ref DropDownList dropDownList)
{
//Create a datatable to sort the drop down list items
DataTable machineDescriptionsTable = new DataTable();
machineDescriptionsTable.Columns.Add("DescriptionCode", typeof(string));
machineDescriptionsTable.Columns.Add("UnitIDString", typeof(string));
machineDescriptionsTable.AcceptChanges();
//Put each of the list items into the datatable
foreach (ListItem currentDropDownListItem in dropDownList.Items) {
string currentDropDownUnitIDString = currentDropDownListItem.Value;
string currentDropDownDescriptionCode = currentDropDownListItem.Text;
DataRow currentDropDownDataRow = machineDescriptionsTable.NewRow();
currentDropDownDataRow["DescriptionCode"] = currentDropDownDescriptionCode.Trim();
currentDropDownDataRow["UnitIDString"] = currentDropDownUnitIDString.Trim();
machineDescriptionsTable.Rows.Add(currentDropDownDataRow);
machineDescriptionsTable.AcceptChanges();
}
//Sort the data table by description
DataView sortedView = new DataView(machineDescriptionsTable);
sortedView.Sort = "DescriptionCode";
machineDescriptionsTable = sortedView.ToTable();
//Clear the items in the original dropdown list
dropDownList.Items.Clear();
//Create a dummy list item at the top
ListItem dummyListItem = new ListItem(" ", "-1");
dropDownList.Items.Add(dummyListItem);
//Begin transferring over the items alphabetically from the copy to the intended drop
downlist
foreach (DataRow currentDataRow in machineDescriptionsTable.Rows) {
string currentDropDownValue = currentDataRow["UnitIDString"].ToString().Trim();
string currentDropDownText = currentDataRow["DescriptionCode"].ToString().Trim();
ListItem currentDropDownListItem = new ListItem(currentDropDownText, currentDropDownValue);
//Don't deal with dummy values in the list we are transferring over
if (!string.IsNullOrEmpty(currentDropDownText.Trim())) {
dropDownList.Items.Add(currentDropDownListItem);
}
}
}
This will take a given drop down list with a Text and a Value property of the list item and put them back into the given drop down list.
Best of Luck!
If you are adding options to the dropdown one by one without a dataset and you want to sort it later after adding items, here's a solution:
DataTable dtOptions = new DataTable();
DataColumn[] dcColumns = { new DataColumn("Text", Type.GetType("System.String")),
new DataColumn("Value", Type.GetType("System.String"))};
dtOptions.Columns.AddRange(dcColumns);
foreach (ListItem li in ddlOperation.Items)
{
DataRow dr = dtOptions.NewRow();
dr["Text"] = li.Text;
dr["Value"] = li.Value;
dtOptions.Rows.Add(dr);
}
DataView dv = dtOptions.DefaultView;
dv.Sort = "Text";
ddlOperation.Items.Clear();
ddlOperation.DataSource = dv;
ddlOperation.DataTextField = "Text";
ddlOperation.DataValueField = "Value";
ddlOperation.DataBind();
This would sort the dropdown items in alphabetical order.
If you are using a data bounded DropDownList, just go to the wizard and edit the bounding query by:
Goto the .aspx page (design view).
Click the magic Arrow ">"on the Dropdown List.
Select "Configure Data source".
Click Next.
On the right side of the opened window click "ORDER BY...".
You will have up two there field cariteria to sort by. Select the desired field and click OK, then click Finish.
You may not have access to the SQL, but if you have the DataSet or DataTable, you can certainly call the Sort() method.
I currently copy the row to an empty datatable and bind that one, but surely there is a better way...
You don't need a data-table to bind - you just need something like a list / enumerable. For example, if you know the row number:
DataRowView row = dt.DefaultView[1]; // second row
detailsView1.DataSource = new DataRowView[] {row};
detailsView1.DataBind();
Note that we have to use DataRowView (rather than DataRow) in order to get the runtime-only properties (i.e. the data from columns). If you have a DataRow, this approach could easily be wrapped in a utility method, for example an extension method:
public static DataRowView[] ForBinding(this DataRow row)
{
foreach (DataRowView rowView in row.Table.DefaultView)
{
if (ReferenceEquals(rowView.Row, row))
{
return new DataRowView[] { rowView };
}
}
throw new ArgumentException("Row not found in the default view", "row");
}
with:
detailsView1.DataSource = row.ForBinding();
detailsView1.DataBind();
yes, it is the most simple way :)
IMHO, If you want to display only 1 field, you might use output parameters, but if you display more than one field in a detailsview it'!s the most simple way.