MVC c# List from string in ViewBag - c#

I am retrieving a string from a MS Sql table, it could be just one name or delimited names: For example Tom or Speaker 1, Speaker 2.
I convert the string to list in the controller using:
Event cevent = db.Events.Find(id);
string speakers = cevent.Speakers;
ViewBag.speakers = "";
if (!String.IsNullOrWhiteSpace(speakers) &&
speakers.Contains(","))
{
ViewBag.speakers = speakers.Split(',').ToList();
}
else
{
ViewBag.speakers = speakers;
}
return View(cevent);
In the view I use the following to display the list:
<ul>
#foreach (var item in ViewBag.speakers)
{
<li> #item </li>
}
</ul>
Works great with the list, I get:
• Speaker 1
• Speaker 2
However, if the ViewBag has just one item, I get:
• T
• o
• m

You might consider always passing an enumerable speaker object to the view regardless of whether or not there are one or more than one speaker.
In your view, you are enumerating over the speakers object, which, in the case of the "Tom", is a list of chars. You might try something like this, instead:
In the controller:
ViewBag.speakers = new List<string>();
string speakers = cevent.Speakers;
var listOfSpeakers = speakers.Split(',').ToList();
foreach (var speaker in listOfSpeakers)
{
ViewBag.speakers.Add(speaker)
}
If you need to format the HTML output differently depending on whether more than one speaker is passed to the view, you can use if(ViewBag.speakers.Count > 1) on the speaker list in a conditional block and handle the output differently in that case.

Related

When assigning value into an Array it returned Object reference not set to an instance of an object

So basically I am trying to get the value from the database and form it into a list so that I can assign each one of them to a dynamic input tag.
View
#foreach (var item in (List<SelectListItem>)ViewBag.AppendTab)
{
#Html.TextBoxFor(m => m.Name[Convert.ToInt32(item.Text)],
new { id = "txtName-" + item.Value, placeholder = "", #class = "form-control"})
#Html.TextBoxFor(m => m.PhoneNo[Convert.ToInt32(item.Text)],
new { id = "txtPhoneNo-" + item.Value, placeholder = "", #class = "form-control"})
/* And Many others field */
}
Controller
List<Student> Model = _StudentBLL.GetAll(SchoolId); // Action that gets the list
if (Model.Count != 0)
{
int counter = 0;
foreach (var item in Model)
{
view.Name[counter] = item.Name;
view.PhoneNo[counter] = item.PhoneNo;
counter++;
}
}
#Beingnin It is referring to this line view.Name[counter] = item.Name; – FENR1R Ace 2 hours ago
View.Name is not null – FENR1R Ace 1 hour ago
If nothing on the left hand side of the = is null then it must be that your GetAll put a null thing in the Model. This model, for example, will also crash with a null reference in the same way:
List<Student> Model = new List<Student>();
Model.Add(null);
How it gets there, is for you to figure out.. You could just exclude them:
foreach (var item in Model.Where(s => s != null))
.. but you should try and find out why they're happening in the first place, so it doesn't trip you up elsewhere in the code when you use GetAll again.
Ultimately, NullRef exceptions are typically very easy to debug; the code crashes and stops, the debugger opens and you just point to every word, or select highlight every expression and then point to it, on the line with your mouse, see which one makes the tooltip say "null". You can also open the immediate window and paste bits of the code line into it and run it, looking for where it says null, e.g pasting ?item into it should say null in your case

ASP.net MVC/EF/C# add none related table records to query in controller

I am trying to add records from table position for positionName(s) to let user select a position for employee when editing.My last attempts is to add a navigation property like field in company model
public virtual ICollection<Position> Mpositions { get; set; }
But all I got so far is null ref exception or no element in viewModel with property "PositionName" ass per viewbag didn't bother using everybody keeps recommending to avoid it so not going to do so either.
public ActionResult Edit([Bind(Include = "CompanyID,CompanyName,EntityForm,Address,Dissolute,CreationDate,FiscaleYear,Description")] Company company)
{
var GlbUpdate = db.Companies.Include(c => c.Members).Include(p => p.Mpositions);
List<Company> mdlCompanies = new List<Company>();
foreach (var item in GlbUpdate)
{
if ((item.Mpositions==null) || (item.Mpositions.Count() == 0))
{
item.Mpositions = (ICollection<Position>)new SelectList(db.Positions.Except((IQueryable<Position>)db.Positions.Select(xk => xk.Members)), "PositionID", "PositionName");
}
mdlCompanies.Add(item);
//I tried first to edit the Mpositions property directly in gblUpdate
//item.Mpositions = (IEnumerable<Position>)db.Positions.Select(p => new SelectListItem { Value = p.PositionID.ToString(), Text = p.PositionName}) ;
//(ICollection<Position>)db.Positions.ToListAsync();
}
In the view I have this
List<SelectListItem> mPositionNames = new List<SelectListItem>();
#*#this yields no results if I try gettign it from the compani record itself it gives a logic error where all id match all positionNames impossible to select an item and only positions already registered are available on the dropDownlist*#
#{foreach (var item in Model.Mpositions)
{
mPositionNames.Add(new SelectListItem() { Text = item.PositionName, Value = item.PositionID.ToString(), Selected = (false) ? true : false });
#*#selected attribute set to false not an issue, no data to select from :p so far*#
}
}
#*#null exception(if i try to midify Mpositions directly in controler) here or empty list if modify it then put it with original query in a new list*#
<div class="SectionContainer R-sectionContainerData" id="MwrapperDataRight">
#Html.DropDownListFor(mpos => item.PositionID, (SelectList)Model.Mpositions)
</div>
All I want to do is pull the positions table to create a drop downList so users can change the position of an employee but since position has a 1>many relation with employee not companies it is not bound automatically by EF nor I seem to be able to use Include() to add it.
Your query for editing positions are complex. This query must edit person's info only. Using Edit action for formalizing position's edit are not correct.It's againts to Single Responsibility Principle. Use ViewComponents for this situation. Load positions separately from person info.
I found a suitable solution using a model that encapsulate the other entities then using Partialviews/RenderAction so each part handles one entity/operation.

The model item passed into the dictionary is of type 'AMSPractice.Models.AddTable'

I am very new to asp.net and i am stuck on that code i cant resolve this error
"The model item passed into the dictionary is of type 'AMSPractice.Models.AddTable', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable`1[AMSPractice.Models.AddTable]'."
I want to show only one value for example in my table there is more than one values name "first" so i want to show only one time "first" so when we write
FirstOrDefault then give error and when we write Where then error is not shown
but i want back only one value where return more then one values.
Here is my code
Controller
public ActionResult Login(string Name,string TeacherID)
{
AdmissionDBEntities obj = new AdmissionDBEntities();
AddTable t = new AddTable();
var v = obj.AddTables.FirstOrDefault(a => a.Teacher.Equals(Name) && a.Teacher_Id.Equals(TeacherID));
if (v != null)
{
**var var = obj.AddTables.FirstOrDefault(b => b.Teacher==Name);**
return View(var);
}
return RedirectToAction("/Home/Index");
and my View is:
#model IEnumerable<AMSPractice.Models.AddTable>
<h3>Classes Assigned</h3>
<br /><br />
<ul>
#foreach (var a in Model)
{
<li>
#Html.ActionLink(a.Class,"Sections","Attendance", new { nid = a.Foreign_Id }, null)
</li>
}
</ul>
Your issue is from the way you have strongly typed your view. From your controller, when you return return View(var); you are passing a single object to your view, yet your view is strongly typed to expect an IEnumerable of the AddTable object.
You either need to return an IEnumerable from your controller, or change your view to expect only a single object.
Try the following to change your view to expect only a single object.
In your view change your strongly typed #model from what you have to #model AMSPractice.Models.AddTable
At that point, you wouldn't need the foreach and you would just have the following.
<li>
#Html.ActionLink(a.Class,"Sections","Attendance", new { nid = Model.Foreign_Id}, null)
</li>

Sort child nodes by date - Razor Umbraco

For the following examples, I'm using a content tree which looks like this:
Content tree
#inherits Umbraco.Web.Mvc.UmbracoTemplatePage
#{
var home = Model.Content.Descendants().Where(x => x.DocumentTypeAlias == "BlogContainer");
<div class="container">
<ul>
#foreach (var item in home)
{
foreach (var items in item.Children)
{
foreach (var baby in items.Children.OrderBy("date desc"))
{
var date = baby.GetPropertyValue<DateTime>("date");
<li>#items.Name - #baby.Name - #date</li>
}
}
}
</ul>
</div>
}
And the result is Result three I need to collect all items and set order by date
Try and do something like
var allItems = homePage.Descendants("YourItemNodeType")
.Where(item => item.HasValue("date")
&& item.GetPropertyValue<DateTime>
("date") != DateTime.MinValue)
.ToList()
.OrderByDescending(item => item.GetPropertyValue<DateTime>("date"));
This should get you all your items in both category 1 and category 2, i always tend to check if my date is actually set ( you wouldnt need to do that for create date mentioned by #bowserm as that is always there with a value).
Once u got them to List then you can sort them by their set date, i do this on when i list news articles in different parent pages, then you can just have one loop to go through all of them.
First of all, what Umbraco version are you using? It looks like you are using 6+? Is that right? My answer below should work for 6 and 7.
The property you are looking for is called createDate, so you would use something like baby.GetPropertyValue<DateTime>("createDate"). Even better, you should be able to just type baby.CreateDate. Umbraco has exposed all of the default properties that you might want on the IPublishedContent as properties, so you can get at those without having to use GetPropretyValue(...).
Take a look at this Umbraco v6 MVC Razor Cheatsheet. It lists the default properties you can get off of the nodes in Umbraco. The razor syntax for v6 will also be applicable to v7, so this cheat sheet works for both.

How to use grid in VS2010 MVC3 to add and edit data?

I'm using Microsoft VS 2010 C#, MVC3.
I have Calsserooms and Students with many to many relation ship, so I add an intermediat table called Classroom_Students.
When adding students to a classroom, I use a combo box in my view filled with all students names, I choose one by one in every submit
#using (Html.BeginForm("AddStudentToClassroom", "Calssrooms", FormMethod.Post))
{
#Html.LabelFor(c=>c.Students, "Choose a Student")
<select name = "StudentID">
#foreach (var it in Model.Students)
{
<option value="#it.ID">#it.StudentName </option>
}
</select>
<input type="submit" value= "Add" />
}
My question is:
How can I use gride, instead of this combo, to select many students, select all or deselect all to add???
I'll appreciate any help.
This is the code in my controller.
For page first call, I fill combobox as following:
[AcceptVerbs(HttpVerbs.Get)]
public ActionResult AddStudentToClassroom(int id) //id of calssroom
{
using (ExaminationEntities en = new ExaminationEntities())
{
ClassroomDetails ClsromView = new ClassroomDetails (); // these are for
ClsromView.Classroom = en.Classroom.Single(c => c.ID == id);// loading calssroom information and to
ClsromView.Students = en.Students.ToList(); // fill students list for the combobox
return View(ClsromView);
}
}
When submiting the form, view, and click the add button, it calls the following overloaded add function for saving data:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult AddStudentToClassroom(AddStudToCals ClasStud) //ClasStud is the submited data from the view
{
using (ExaminationEntities en = new ExaminationEntities())
{
ClassroomDetails ClsromView = new ClassroomDetails(); // these are for
ClsromView.Calssroom = en.Calssroom.Single(c => c.ID == ClasStud.ClassroomID); // loading calssroom information and to
ClsromView.Students = en.Student.ToList(); // fill students list for the combobox
using (ExaminationEntities exn = new ExaminationEntities())
{
Calssroom_Student To_DB_ClasStud = new Calssroom_Student (); //To_DB_ClasStud object to get the submited values and to save it in the DB
To_DB_ClasStud.CalssroomID = ClasStud.CalssroomID;
To_DB_ClasStud.StudentID = ClasStud.StdentID;
en.AddToClassroom_Student(To_DB_ClasStud);
en.SaveChanges();
}
return View(ClsromView);
}
}
Well, the option that requires the least changes to your markup is to add the multiple property to your select. Then, change the action method to accept a params int[] ids, iterate through them, and you should be good-to-go. At worst, you might have to change your parameter to a string and do a Split() on ,, but I don't recall that being how the model binder supports multi-selects.
If this doesn't seem to fit your needs, there is an article on the ASP.NET website that explains using a MultiSelectList to bind to the ListBox helper, here:
http://www.asp.net/mvc/tutorials/javascript/working-with-the-dropdownlist-box-and-jquery/using-the-dropdownlist-helper-with-aspnet-mvc

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