For the purposes of invoicing, I'm keeping track of timesheet entries that are associated with an invoice by storing the selected timesheets in the browser Session and adding/removing entries to that list as the user updates:
The GridView loads all timesheets for the selected company and then indicates by changing row style and select button text:
private void HighlightInvoiceTimesheets()
{
var timesheets = Session["invoiceTimesheets"] as List<Timesheet>;
var invoiceTotalHours = 0;
foreach (var timesheet in timesheets)
{
var tid = timesheet.Id.ToString();
foreach (GridViewRow row in ItemsGrid.Rows)
{
var btn = row.Cells[ItemsGrid.Columns.Count - 1].Controls[0] as LinkButton;
if (ItemsGrid.DataKeys[row.RowIndex].Values["Id"].ToString() == tid)
{
row.CssClass = "success";
btn.Text = "Remove";
int.TryParse(row.Cells[5].Text, out int timesheetHours);
invoiceTotalHours += timesheetHours;
}
}
}
Session["invoiceTotalHours"] = invoiceTotalHours;
BillableHoursLabel.Text = invoiceTotalHours.ToString();
}
When the user "selects" an item in the GridView, it adds or removes the item from the collection in the Session and updates the GridView accordingly:
protected void ItemsGrid_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
{
// Get the list of timesheets associated with the invoice.
var list = (Session["invoiceTimesheets"] == null) ? new List<Timesheet>() : Session["invoiceTimesheets"] as List<Timesheet>;
// Get the selected timesheet.
int.TryParse(ItemsGrid.DataKeys[e.NewSelectedIndex].Values["Id"].ToString(), out int timesheetId);
var timesheet = timesheetService.GetClearTimesheet(timesheetId);
// Get the select button to update its text.
var btn = ItemsGrid.Rows[e.NewSelectedIndex].Cells[ItemsGrid.Columns.Count - 1].Controls[0] as LinkButton;
// Get the total hours billable for the invoice based on the total hours of the timesheets.
var invoiceTotalHours = (Session["invoiceTotalHours"] == null) ? 0 : int.Parse(Session["invoiceTotalHours"].ToString());
if (list.Find(x => x.Id == timesheetId) != null)
{
// The list contains the selected item, remove it and indicate removed.
list.Remove(timesheet);
ItemsGrid.Rows[e.NewSelectedIndex].CssClass = "";
btn.Text = "Select";
int.TryParse(Session["invoiceTotalHours"].ToString(), out invoiceTotalHours);
invoiceTotalHours -= timesheet.BillableHours;
}
else
{
// The list doesn't contain the selected item, add it and indicate added.
list.Add(timesheet);
ItemsGrid.Rows[e.NewSelectedIndex].CssClass = "success";
btn.Text = "Remove";
int.TryParse(Session["invoiceTotalHours"].ToString(), out invoiceTotalHours);
invoiceTotalHours += timesheet.BillableHours;
}
BillableHoursLabel.Text = invoiceTotalHours.ToString();
// Update the collection in the session.
Session["invoiceTimesheets"] = list;
}
This works without any errors but I'm very confused why list.Remove(timesheet); doesn't actually update the list in memory.
As a result of this, the collection in the session doesn't get updated and changes made don't reflect on the database.
It's because the timesheet you're trying to remove isn't the same object as the one you get from
var timesheet = timesheetService.GetClearTimesheet(timesheetId);
instead of this:
if (list.Find(x => x.Id == timesheetId) != null)
{
// The list contains the selected item, remove it and indicate removed.
list.Remove(timesheet);
Do this:
var timeSheetSession=list.FirstOrDefault(x => x.Id == timesheetId);
if(timeSheetSession!=null) list.Remove(timeSheetSession);
it's pseudo code, i didn't test it.
I'm working on an ASP.NET webforms page that queries the database for a list of entries in the Study table. These entries are to be passed into the dropdownlist. When a study is selected from the dropdownlist, the studyID is to be passed to the GetResponses method to retrieve associated data from a stored procedure.
I receive Input String was not in a Correct Format with the following snippets:
private DataTable LoadStudies(int iStudyID )
{
ddlStudies.Items.Clear();
ddlStudies.SelectedValue = "0";
DataTable dt = new DataTable();
using (PROTOTYPING db = new PROTOTYPING(ConfigurationManager.ConnectionStrings["SQL"].ConnectionString))
{
var query = (from d in db.Studies
where d.StudyStatus == 0 //Closed...
orderby d.StudyName
select new
{
d.StudyName,
d.StudyID,
});
if (query.Count() > 0)
{
foreach (var a in query)
{
ddlStudies.Items.Add(new ListItem(a.StudyID.ToString()));
}
}
dt.Dispose();
DataView dv = new DataView(dt);
return dt;
}
}
The error is thrown on the Page_Load which is currently written as follows:
protected void Page_Load(object sender, EventArgs e)
{
int iUserID = 0;
if (Session["UserID"] == null)
{
Response.Redirect("Default.aspx");
}
iUserID = Convert.ToInt32(Session["UserID"]);
int iRole = 0;
iRole = Convert.ToInt32(Session["RoleID"]);
if (!Page.IsPostBack)
{
LoadStudies(Convert.ToInt32(ddlStudies.SelectedValue));
GetResponses(Convert.ToInt32(ddlStudies.SelectedValue));
ddlStudies.DataSource = LoadStudies(Convert.ToInt32(ddlStudies.SelectedValue));
ddlStudies.DataTextField = "StudyName";
ddlStudies.DataValueField = "StudyID";
ddlStudies.DataBind();
}
}
How do I resolve the error, which is thrown when assigning the dropdownlist's DataSource to the LoadStudies method?
ddlStudies.SelectedValue is not a valid integer value 0,1,2 etc.
I would wager a guess it's an empty string. Convert.ToInt32(""), which will throw the exception you are experiencing.
Interestingly Convert.ToInt32(null) will return a zero.
Try
Convert.ToInt32(string.IsNullOrWhiteSpace(ddlStudies.SelectedValue) ? null : ddlStudies.SelectedValue)
I have performed enormous amount of Google search on this topic but couldn't really find the proper answer to this question. The solution might be simple, but I am a beginner to C# ASP.NET.
I have some code that is taking and storing user inputs from a dropdown list and a textbox into its individual List. I am trying to display both lists in a single gridview as individual columns. For an example, when a user selects a product and type in the quantity and hits the add button, it should display the details in a single row of a gridview. Now I have achieved saving the data into a list but cannot get it to display it in a single row.
Here is my code:
List<string> productIdList = new List<string>();
List<string> productTemp = new List<string>();
List<string> quantityList = new List<string>();
List<string> quantityTemp = new List<string>();
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
productTemp = (List<string>)ViewState["productId"];
quantityTemp = (List<string>)ViewState["quantity"];
string str1 = Convert.ToString(productTemp);
string str2 = Convert.ToString(quantityTemp);
if (str1 != "")
{
if (productTemp.Count != 0)
{
foreach (string ids in productTemp)
{
productIdList.Add(ids);
}
}
}
if (str2 != "")
{
if (quantityTemp.Count != 0)
{
foreach (string qtys in quantityTemp)
{
quantityList.Add(qtys);
}
}
}
}
}
protected void btnContinue_Click(object sender, EventArgs e)
{
productIdList.Add(ddlProduct.SelectedValue.ToString());
quantityList.Add(txtQuantity.Text);
ViewState["productId"] = productIdList;
ViewState["quantity"] = quantityList;
txtQuantity.Text = "";
ArrayList testList = new ArrayList();
testList.AddRange(productIdList);
testList.AddRange(quantityList);
grdTest.DataSource = testList;
grdTest.DataBind();
grdProduct.DataSource = productIdList;
grdProduct.DataBind();
grdQuantity.DataSource = quantityList;
grdQuantity.DataBind();
}
}
The gridview currently present are for test purpose to check if data persists after every click of button. grdTest is what I am using for trying to display my list as columns.
Final would be something like this:
Name Qty
----- -----
Name1(list1) 5(list2)
Thanks!
You can use Linq to create List of object with Name and Qty from two lists like below
var temp = productIdList.Zip(quantityList, (n, w) => new { Name = n, Qty = w });
grdTest.DataSource = temp.ToList();
grdTest.DataBind();
Gridview you have to show both name and quantity in one row, if you join name and quantity to a one list it will not display as you expected ( all will show in one column)
we can create new class with Name and Qty as properties and create List of items by iterating though productIdList and quantityList.
Read more about Enumerable.Zip
I am trying to implement a checkbox within gridview,
The job of this checkbox is to verify a record,
When this verify button is pressed, all items with a checked checkbox are inputted into the database
This is my code:
protected void Button1_Click(object sender, EventArgs e)
{
foreach (GridViewRow row in GridView1.Rows)
{
CheckBox cbox = ((CheckBox)row.FindControl("Verify"));
if (cbox.Equals(true))
{
String DraftsText = ((TextBox)row.FindControl("numDrafts")).Text;
String TCtext = ((TextBox)row.FindControl("numTC")).Text;
if (row.RowType == DataControlRowType.DataRow)
{
//Header trs = new Header();
// GridView1.Rows[0].FindControl("numTC");
if (TCtext != "" && DraftsText != "")
{
// try
// {
string date = row.Cells[4].Text;
DateTime dateTime = Convert.ToDateTime(date);
string dateFormatted = dateTime.ToString("d-MMM-yy");
string unit = row.Cells[5].Text;
string currency = row.Cells[6].Text;
string totalFC = row.Cells[7].Text;
string totalDC = row.Cells[8].Text;
int d = Convert.ToInt32(DraftsText);
int tc = Convert.ToInt32(TCtext);
hdr = new Header(d, tc, dateFormatted, unit, currency, totalFC, totalDC);
hdr.InsertFCTC(hdr);
}
}
}
}
}
I might be going at this the wrong way but in the if (cbox.Equals(true))
its giving me an exception: Object reference not set to an instance of an object.
Any idea what i can do to solve this?
Many Thanks
This if (cbox.Equals(true)) should be if (cbox.Checked)
Since your cbox is a checkbox object it can't be used to compare, so you have to use the cbox Checked Property, which will return true/false
You receive a NullPointerException because the suggested checkbox wasn't found! Or the direct cast into an instance of type CheckBox doesn't worked as expected.
Change your code to something like this and retry:
CheckBox cbox = ((CheckBox)row.FindControl("Verify"));
if (cbox != null && cbox.Checked)
{
....
}
I have a datagridview on my form and I populate it with this:
dataGridView1.DataSource = students.Select(s => new { ID = s.StudentId, RUDE = s.RUDE, Nombre = s.Name, Apellidos = s.LastNameFather + " " + s.LastNameMother, Nacido = s.DateOfBirth })
.OrderBy(s => s.Apellidos)
.ToList();
Now, I use the s.Apellidos as the default sort, but I'd also like to allow users to sort when clicking on the column header.
This sort will not modify the data in any way, it's just a client side bonus to allow for easier searching for information when scanning the screen with their eyes.
Thanks for the suggestions.
Set all the column's (which can be sortable by users) SortMode property to Automatic
dataGridView1.DataSource = students.Select(s => new { ID = s.StudentId, RUDE = s.RUDE, Nombre = s.Name, Apellidos = s.LastNameFather + " " + s.LastNameMother, Nacido = s.DateOfBirth })
.OrderBy(s => s.Apellidos)
.ToList();
foreach(DataGridViewColumn column in dataGridView1.Columns)
{
column.SortMode = DataGridViewColumnSortMode.Automatic;
}
Edit: As your datagridview is bound with a linq query, it will not be sorted. So please go through this [404 dead link, see next section] which explains how to create a sortable binding list and to then feed it as datasource to datagridview.
Code as recovered from dead link
Link from above is 404-dead. I recovered the code from the Internet Wayback Machine archive of the page.
public Form1()
{
InitializeComponent();
SortableBindingList<person> persons = new SortableBindingList<person>();
persons.Add(new Person(1, "timvw", new DateTime(1980, 04, 30)));
persons.Add(new Person(2, "John Doe", DateTime.Now));
this.dataGridView1.AutoGenerateColumns = false;
this.ColumnId.DataPropertyName = "Id";
this.ColumnName.DataPropertyName = "Name";
this.ColumnBirthday.DataPropertyName = "Birthday";
this.dataGridView1.DataSource = persons;
}
As Niraj suggested, use a SortableBindingList. I've used this very successfully with the DataGridView.
Here's a link to the updated code I used - Presenting the SortableBindingList - Take Two - archive
Just add the two source files to your project, and you'll be in business.
Source is in SortableBindingList.zip - 404 dead link
One more way to do this is using "System.Linq.Dynamic" library. You can get this library from Nuget. No need of any custom implementations or sortable List :)
using System.Linq.Dynamic;
private bool sortAscending = false;
private void dataGridView_ColumnHeaderMouseClick ( object sender, DataGridViewCellMouseEventArgs e )
{
if ( sortAscending )
dataGridView.DataSource = list.OrderBy ( dataGridView.Columns [ e.ColumnIndex ].DataPropertyName ).ToList ( );
else
dataGridView.DataSource = list.OrderBy ( dataGridView.Columns [ e.ColumnIndex ].DataPropertyName ).Reverse ( ).ToList ( );
sortAscending = !sortAscending;
}
You don't need to create a binding datasource. If you want to apply sorting for all of your columns, here is a more generic solution of mine;
private int _previousIndex;
private bool _sortDirection;
private void gridView_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.ColumnIndex == _previousIndex)
_sortDirection ^= true; // toggle direction
gridView.DataSource = SortData(
(List<MainGridViewModel>)gridReview.DataSource, gridReview.Columns[e.ColumnIndex].Name, _sortDirection);
_previousIndex = e.ColumnIndex;
}
public List<MainGridViewModel> SortData(List<MainGridViewModel> list, string column, bool ascending)
{
return ascending ?
list.OrderBy(_ => _.GetType().GetProperty(column).GetValue(_)).ToList() :
list.OrderByDescending(_ => _.GetType().GetProperty(column).GetValue(_)).ToList();
}
Make sure you subscribe your data grid to the event ColumnHeaderMouseClick. When the user clicks on the column it will sort by descending. If the same column header is clicked again, sorting will be applied by ascending.
your data grid needs to be bound to a sortable list in the first place.
Create this event handler:
void MakeColumnsSortable_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
{
//Add this as an event on DataBindingComplete
DataGridView dataGridView = sender as DataGridView;
if (dataGridView == null)
{
var ex = new InvalidOperationException("This event is for a DataGridView type senders only.");
ex.Data.Add("Sender type", sender.GetType().Name);
throw ex;
}
foreach (DataGridViewColumn column in dataGridView.Columns)
column.SortMode = DataGridViewColumnSortMode.Automatic;
}
And initialize the event of each of your datragrids like this:
dataGridView1.DataBindingComplete += MakeColumnsSortable_DataBindingComplete;
You can use DataGridViewColoumnHeaderMouseClick event like this :
Private string order = String.Empty;
private void dgvDepartment_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
if (order == "d")
{
order = "a";
dataGridView1.DataSource = students.Select(s => new { ID = s.StudentId, RUDE = s.RUDE, Nombre = s.Name, Apellidos = s.LastNameFather + " " + s.LastNameMother, Nacido = s.DateOfBirth }) .OrderBy(s => s.Apellidos).ToList();
}
else
{
order = "d";
dataGridView1.DataSource = students.Select(s => new { ID = s.StudentId, RUDE = s.RUDE, Nombre = s.Name, Apellidos = s.LastNameFather + " " + s.LastNameMother, Nacido = s.DateOfBirth }.OrderByDescending(s => s.Apellidos) .ToList()
}
}
there is quite simply solution when using Entity Framework (version 6 in this case). I'm not sure but it seems to ObservableCollectionExtensions.ToBindingList<T> method returns implementation of sortable binding list. I haven't found source code to confirm this supposition but object returning from this method works with DataGridView very well especially when sorting columns by clicking on its headers.
The code is very simply and relies only on .net and entity framework classes:
using System.Data.Entity;
IEnumerable<Item> items = MethodCreatingItems();
var observableItems = new System.Collections.ObjectModel.ObservableCollection<Item>(items);
System.ComponentModel.BindingList<Item> source = observableItems.ToBindingList();
MyDataGridView.DataSource = source;
put this line in your windows form (on load or better in a public method like "binddata" ):
//
// bind the data and make the grid sortable
//
this.datagridview1.MakeSortable( myenumerablecollection );
Put this code in a file called DataGridViewExtensions.cs (or similar)
// MakeSortable extension.
// this will make any enumerable collection sortable on a datagrid view.
//
// BEGIN MAKESORTABLE - Mark A. Lloyd
//
// Enables sort on all cols of a DatagridView
//
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
public static class DataGridViewExtensions
{
public static void MakeSortable<T>(
this DataGridView dataGridView,
IEnumerable<T> dataSource,
SortOrder defaultSort = SortOrder.Ascending,
SortOrder initialSort = SortOrder.None)
{
var sortProviderDictionary = new Dictionary<int, Func<SortOrder, IEnumerable<T>>>();
var previousSortOrderDictionary = new Dictionary<int, SortOrder>();
var itemType = typeof(T);
dataGridView.DataSource = dataSource;
foreach (DataGridViewColumn c in dataGridView.Columns)
{
object Provider(T info) => itemType.GetProperty(c.Name)?.GetValue(info);
sortProviderDictionary[c.Index] = so => so != defaultSort ?
dataSource.OrderByDescending<T, object>(Provider) :
dataSource.OrderBy<T,object>(Provider);
previousSortOrderDictionary[c.Index] = initialSort;
}
async Task DoSort(int index)
{
switch (previousSortOrderDictionary[index])
{
case SortOrder.Ascending:
previousSortOrderDictionary[index] = SortOrder.Descending;
break;
case SortOrder.None:
case SortOrder.Descending:
previousSortOrderDictionary[index] = SortOrder.Ascending;
break;
default:
throw new ArgumentOutOfRangeException();
}
IEnumerable<T> sorted = null;
dataGridView.Cursor = Cursors.WaitCursor;
dataGridView.Enabled = false;
await Task.Run(() => sorted = sortProviderDictionary[index](previousSortOrderDictionary[index]).ToList());
dataGridView.DataSource = sorted;
dataGridView.Enabled = true;
dataGridView.Cursor = Cursors.Default;
}
dataGridView.ColumnHeaderMouseClick+= (object sender, DataGridViewCellMouseEventArgs e) => DoSort(index: e.ColumnIndex);
}
}
KISS : Keep it simple, stupid
Way A:
Implement an own SortableBindingList class when like to use DataBinding and sorting.
Way B:
Use a List<string> sorting works also but does not work with DataBinding.
I suggest using a DataTable.DefaultView as a DataSource. Then the line below.
foreach (DataGridViewColumn column in gridview.Columns)
{
column.SortMode = DataGridViewColumnSortMode.Automatic;
}
After that the gridview itself will manage sorting(Ascending or Descending is supported.)
If you get an error message like
An unhandled exception of type 'System.NullReferenceException'
occurred in System.Windows.Forms.dll
if you work with SortableBindingList, your code probably uses some loops over DataGridView rows and also try to access the empty last row! (BindingSource = null)
If you don't need to allow the user to add new rows directly in the DataGridView this line of code easily solve the issue:
InitializeComponent();
m_dataGridView.AllowUserToAddRows = false; // after components initialized
...
Create a class which contains all properties you need, and populate them in the constructor
class Student
{
int _StudentId;
public int StudentId {get;}
string _Name;
public string Name {get;}
...
public Student(int studentId, string name ...)
{ _StudentId = studentId; _Name = name; ... }
}
Create an IComparer < Student > class, to be able to sort
class StudentSorter : IComparer<Student>
{
public enum SField {StudentId, Name ... }
SField _sField; SortOrder _sortOrder;
public StudentSorder(SField field, SortOrder order)
{ _sField = field; _sortOrder = order;}
public int Compare(Student x, Student y)
{
if (_SortOrder == SortOrder.Descending)
{
Student tmp = x;
x = y;
y = tmp;
}
if (x == null || y == null)
return 0;
int result = 0;
switch (_sField)
{
case SField.StudentId:
result = x.StudentId.CompareTo(y.StudentId);
break;
case SField.Name:
result = x.Name.CompareTo(y.Name);
break;
...
}
return result;
}
}
Within the form containing the datagrid add
ListDictionary sortOrderLD = new ListDictionary(); //if less than 10 columns
private SortOrder SetOrderDirection(string column)
{
if (sortOrderLD.Contains(column))
{
sortOrderLD[column] = (SortOrder)sortOrderLD[column] == SortOrder.Ascending ? SortOrder.Descending : SortOrder.Ascending;
}
else
{
sortOrderLD.Add(column, SortOrder.Ascending);
}
return (SortOrder)sortOrderLD[column];
}
Within datagridview_ColumnHeaderMouseClick event handler do something like this
private void dgv_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
StudentSorter sorter = null;
string column = dGV.Columns[e.ColumnIndex].DataPropertyName; //Use column name if you set it
if (column == "StudentId")
{
sorter = new StudentSorter(StudentSorter.SField.StudentId, SetOrderDirection(column));
}
else if (column == "Name")
{
sorter = new StudentSorter(StudentSorter.SField.Name, SetOrderDirection(column));
}
...
List<Student> lstFD = datagridview.DataSource as List<Student>;
lstFD.Sort(sorter);
datagridview.DataSource = lstFD;
datagridview.Refresh();
}
Hope this helps
Just in case somebody still looks for it, I did it on VS 2008 C#.
On the Event ColumnHeaderMouseClick, add a databinding for the gridview, and send the order by field like a parameter. You can get the clicked field as follows:
dgView.Columns[e.ColumnIndex].Name
In my case the header's names are similar to view field names.
I have a BindingList<> object bind as a data source to dataGridView.
BindingList x1;
x1 = new BindingList<sourceObject>();
BindingSource bsx1 = new BindingSource();
bsx1.DataSource = x1;
dataGridView1.DataSource = bsx1;
When I clicked the column header, no sorting takes place.
I used the SortableBindingList answer provided by Tom Bushell.
Having included two source files into my project
SortableBindingList.cs
PropertyComparer.cs
Then this change is made to my code:
Be.Timvw.Framework.ComponentModel.SortableBindingList x1; // 1
x1 = new Be.Timvw.Framework.ComponentModel.SortableBindingList<sourceObject>(); // 2
BindingSource bsx1 = new BindingSource();
bsx1.DataSource = x1;
dataGridView1.DataSource = bsx1;
After these changes I performed a build on my program. I am now able to sort by clicking the column headers. Only two lines need changing, they are highlighted in the code snippet above by trailing comments.
In my case, the problem was that I had set my DataSource as an object, which is why it didn't get sorted. After changing from object to a DataTable it workd well without any code complement.
If using a DataTable: dgv.DataSource = (DataTable)table
You can automatically enable Sorting for objects that contain the IComparable Interface. After creating the DataTable, when adding the columns be sure to set the type also to at least object:
table.Columns.Add("ColumnName", typeof(object))
Otherwise, if you do Not specifically give it a type, it converts the object to a string.
I spent a fair amount of time creating a dgv_ColumnHeaderMouseClick() event because it was Not sorting the DataGridView correctly, then to find that all you need to do is specify the type for the column name, and it sorts properly. And the reason it was not sorting correctly previously was because without specifying the type for DataTable columns, it will convert objects to strings.
Just instead of passing a list to the datagrid, you store the search result as a datatable.
dataGridView1.DataSource = students
.Select(s => new {
ID = s.StudentId,
RUDE = s.RUDE,
Nombre = s.Name,
Apellidos = s.LastNameFather + " " + s.LastNameMother,
Nacido = s.DateOfBirth })
.OrderBy(s => s.Apellidos)
.ToDataTable();