In my Controller i have a method like this:
public string _Count(int id)
{
return (repositoryModeli_marka.Modeli_marka.Count(c => c.parent == id).ToString());
}
and then in my view i call this method with:
#foreach (var i in Model)
{
Html.RenderAction("_Count", "Modeli_marka", new { id = i.id })
}
and this works fine. I get the count number i my view.
Now i need to check this number, something like this:
#foreach (var i in Model)
{
if (Html.RenderAction("_Count", "Modeli_marka", new { id = i.id }) == "")
{
}
}
and i cant do that becouse it say void == int or == string. How can i accomplish this?
thx in advance
Related
I have 5 records coming from a simple select stored procedure.
ID Name
1 RecordOne
2 RecordTwo
3 RecordThree
4 RecordFour
5. RecordFive
Requirement is to display one record at a time example:
Record One
Previous Next
Two Action links or buttons with Previous and Next text.
If user clicks Next user will see
RecordTwo
and so on,same for previous case.
My model
namespace MVCLearning.Models
{
public class VMNews
{
public List<Student> StudentDetails { get; set; }
}
public class Student
{
public int ID { get; set; }
public string Name { get; set; }
}
}
Action
public ActionResult Index()
{
VMNews objnews = new VMNews();
objnews.StudentDetails = db.Database.SqlQuery<Student>("usp_studentdetails").ToList();
return View(objnews);
}
View
<div>
#foreach (var item in Model.SD.Take(1))
{
<h3>#item.Name</h3>
<h3>#item.Age</h3>
}
#Html.ActionLink("Next", "index", new { Model.SD[0].ID})
#Html.ActionLink("Previous", "index", new { Model.SD[0].ID })
The way I have written the view is totally wrong am not getting how and what to write on the action and what to write on the View.
What will be one of the way to achieve this.
Change you method to
public ActionResult Index(int? index)
{
int max = 5; // modify based on the actual number of records
int currentIndex = index.GetValueOrDefault();
if (currentIndex == 0)
{
ViewBag.NextIndex = 1;
}
else if (currentIndex >= max)
{
currentIndex = max;
ViewBag.PreviousIndex = currentIndex - 1;
}
else
{
ViewBag.PreviousIndex = currentIndex - 1;
ViewBag.NextIndex = currentIndex + 1;
}
VMNews objnews = new VMNews();
Student model = db.Database.SqlQuery<Student>("usp_studentdetails")
.Skip(currentIndex).Take(1).FirstOrDefault();
return View(model);
}
Note that the query has been modified to return only one Student since that is all that you require in the view. Also I have asssumed if a user enters a value greater than the number of records it will return the last record (you may in fact want to throw an error?)
The view now needs to be
#model Student
<h3>#Model.Name</h3>
<h3>#Model.Age</h3>
#if (ViewBag.PreviousIndex != null)
{
#Html.ActionLink("Previous", "Index", new { index = ViewBag.PreviousIndex })
}
#if (ViewBag.NextIndex != null)
{
#Html.ActionLink("Next", "Index", new { index = ViewBag.NextIndex })
}
The following code is taken from the tutorial: http://www.asp.net/mvc/tutorials/getting-started-with-aspnet-mvc3/cs/examining-the-edit-methods-and-edit-view which shows how ASP.net MVC 3 can be used to manage a movie database.
In the tutoral, a list object is added to the controller class that contains every movie genre that exists in the database. This list is then passed to a drop-down in the view enabling the database to be searched by genre.
Controller: (code related to movie genre in bold)
public ActionResult SearchIndex(string movieGenre, string searchString)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == movieGenre));
}
}
What I want to do is enhance this further so that the movies can be searched by price as well as genre. I know I can re-use the much of the same code to do this. I think I need to create a new class that the controller class can pass either the genre or price. Is this correct? IF so, I'd appreciate an example. Thanks.
Update/Clarification:
I want to avoid repeating the code for both genre and price as below:
public ActionResult SearchIndex(string movieGenre, string searchString,float moviePrice)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var PriceLst = new List<string>();
var PriceQry = from d in db.Movies
orderby d.Genre
select d.Genre;
PriceLst.AddRange(GenreQry.Distinct());
ViewBag.moviePrice = new SelectList(PriceLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == movieGenre));
}
if (string.IsNullOrEmpty(moviePrice))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == moviePrice));
}
}
You just have to insert a text box in the view to get price value. Then receive this value at action and modify the query to get desired results.
like this:
#Html.ActionLink("Create New", "Create")
#using (Html.BeginForm()){
<p>Genre: #Html.DropDownList("movieGenre", "All")
Title: #Html.TextBox("SearchString")
Price: #Html.TextBox("Price")
<input type="submit" value="Filter" /></p>
}
And in the action method you are using the code below to populate the dropdownlist with genre values. You need not do the same for price value.
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
And in your action method you just have to use the value of price to filter data
public ActionResult SearchIndex(string movieGenre, string searchString,float price)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where((x => x.Genre == movieGenre) &&(x => x.Price== price)));
}
}
You can do it in so many different ways while all are correct but it depends on the complexity of your project. Basically you don't want to over-engineer a simple program. But in general you should move all of your logic to a separate class and use your actions for creating and calling the right logic class:
public class GetMoviesRequest
{
public string Name { get; set; }
public float? Price { get; set; }
}
public class MoviesLogic
{
private List<Movie> Movies;
public IEnumerable<Movie> Get(GetMoviesRequest request)
{
IEnumerable<Movie> filtered = Movies.AsQueryable();
if (!string.IsNullOrEmpty(request.Name))
{
//Filter by name
filtered = filtered.Where(m => m.Name == request.Name);
}
if (request.Price.HasValue)
{
//Filter by value
filtered = filtered.Where(m => m.Price == request.Price);
}
return filtered;
}
}
public class MyController
{
public ActionResult SearchIndex(string movieGenre, string searchString)
{
var logic = new MoviesLogic();
var movies = logic.Get(new GetMoviesRequest() { Name = searchString } )
///do stuff with movies
}
}
My code is working nicelly but I would like to know if you can suggest something more performatic to get the values frm my dynamic controls.
public class Obj
{
public int ID { get; set; }
public int Quantity { get; set; }
public List<int> getValues (List<Obj> myList)
{
List<Obj> listQuatity = new List<Obj>();
foreach (Obj item in myList)
{
listQuatity.Add(new Obj
{
ID = item.ID,
Quantity = Request.Params["codControl" + item.ID].Trim().Equals("")
? 0
: Convert.ToInt32(Request.Params["codControl" + item.ID])
});
}
}
}
There is no much space for optimization, your loop is pretty simple and straightforward.
One thing I would improve - caching of the Request.Param value instead accessing it twice:
(This could be rewritten using LINQ so would look more elegant but it would not be faster)
public List<int> getValues(List<Obj> myList)
{
List<Obj> listQuatity = new List<Obj>();
foreach (Obj item in myList)
{
// access it once so code would be slightly faster
// but much clear
var requestParam = Request.Params["codControl" + item.ID].Trim();
listQuatity.Add(new Obj
{
ID = item.ID,
Quantity = requestParam.Equals(String.Empty)
? 0
: Convert.ToInt32(requestParam)
});
}
}
Let's see how LINQ query would look:
List<Obj> listQuatity =
myList.Select(i => new {
Id = i.ID,
Param = Request.Params["codControl" + item.ID].Trim(),
})
.Select(i => new Obj {
ID = i.Id,
Quantity = Param.Equals(String.Empty)
? 0
: Convert.ToInt32(i.Param)
})
.ToList();
I'm a linq noob.... can someone please some me how to achieve this using linq... I'm trying to compare 2 lists in both directions...
internal void UpdateUserTeams(int iUserID)
{
UserTeamCollection CurrentTeams = GetUserTeams(iUserID);
UserTeamCollection UpdatedTeams = this;
foreach (UserTeam ut in CurrentTeams)
{
if(!UpdatedTeams.ContainsTeam(ut.ID))
{
RemoveTeamFromDB();
}
}
foreach (UserTeam ut in UpdatedTeams)
{
if (!CurrentTeams.ContainsTeam(ut.ID))
{
AddTeamToDB();
}
}
}
public bool ContainsTeam(int iTeamID)
{
return this.Any(t => t.ID == iTeamID);
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Linqage
{
class Program
{
static void Main(string[] args)
{
UserTeamCollection currentTeams = new UserTeamCollection()
{
new UserTeam(1),
new UserTeam(2),
new UserTeam(3),
new UserTeam(4),
new UserTeam(5)
};
UserTeamCollection updatedTeams = new UserTeamCollection()
{
new UserTeam(2),
new UserTeam(4),
new UserTeam(6),
new UserTeam(8)
};
currentTeams.Except(updatedTeams).All(u =>
{
//Console.WriteLine("Item ID: {0}",u.ID);
//RemoveFromDB()
return true;
});
updatedTeams.Except(currentTeams).All(u =>
{
//Console.WriteLine("Item ID: {0}", u.ID);
//AddToDB()
return true;
});
}
}
public class UserTeamCollection
: List<UserTeam>
{
}
//Either overwrite the GetHashCode and Equals method OR create a IComparer
public class UserTeam
{
public int ID { get; set; }
public UserTeam(int id)
{
ID = id;
}
public override bool Equals(object obj)
{
UserTeam iOther = obj as UserTeam;
if (iOther != null)
{
return this.ID == iOther.ID;
}
return false;
}
public override int GetHashCode()
{
return ID.GetHashCode();
}
}
}
So converting your initial question to an english requirement:
foreach (UserTeam ut in CurrentTeams) // for each current team
{
if(!UpdatedTeams.ContainsTeam(ut.ID)) // that is not in the updated teams list
{
RemoveTeamFromDB(); // remove it from the database
}
}
foreach (UserTeam ut in UpdatedTeams) //for each of the teams in the updated teams list
{
if (!CurrentTeams.ContainsTeam(ut.ID)) //if the current team does not contain the updated team
{
AddTeamToDB(); //add the team to the database
}
}
Therefore, you want to do:
//select all current teams that are not in updated teams list
CurrentTeam.Except(UpdatedTeams).All(team => { RemoveTeamFromDB(team); return true; });
//select all updated teams that are not in the current teams list
UpdatedTeam.Except(CurrentTeams).All(team => { AddTeamToDB(team); return true; });
Make sure your UserTeam object has proper overrides for the Equals and GetHashCode methods, so that comparison between two UserTeams is accurate :)
You would normally use Enumerable.Except both ways to get the differences. Then add and remove as needed.
var addedTeams = UpdatedTeams.Except(CurrentTeams);
var removedTeams = CurrentTeams.Except(UpdatedTeams);
You're trying to get the outer parts from a full outer join. Here's a rough way to achieve that.
ILookup<int, UserTeam> currentLookup = CurrentTeams
.ToLookup(ut => ut.ID);
ILookup<int, UserTeam> updatedLookup = UpdatedTeams
.ToLookup(ut => ut.ID);
List<int> teamIds = CurrentTeams.Select(ut => ut.ID)
.Concat(UpdatedTeams.Select(ut => ut.ID))
.Distinct()
.ToList();
ILookup<string, UserTeam> results =
(
from id in teamIds
let inCurrent = currentLookup[id].Any()
let inUpdated = updatedLookup[id].Any()
let key = inCurrent && inUpdated ? "No Change" :
inCurrent ? "Remove" :
inUpdated ? "Add" :
"Inconceivable"
let teams = key == "Remove" ? currentLookup[id] :
updatedLookup[id]
from team in teams
select new {Key = key, Team = team)
).ToLookup(x => x.Key, x => x.Team);
foreach(UserTeam ut in results["Remove"])
{
RemoveTeamFromDB();
}
foreach(UserTeam ut in results["Add"])
{
AddTeamToDB();
}
Assume that we have class
public class RMenuItem
{
public List<RMenuItem> ChildrenItems { get; }
public decimal OperationID { get; }
public string Name { get; }
}
as you can see - each menuitem could have children items - as usual in menu.
My task is to iterate through each items of this list and apply some action to it. Classical decision is to write recursive iteration. But I'm interesting if LINQ could make my task easier? For example, I suppose that we can write query that can get flat list of objects, which i can iterate simply with foreach. But my attempts in this way weren't successful yet.
So any help appreciated!
It's possible:
public void PrintAllNames(RMenuItem rootItem)
{
Action<RMenuItem> print = null;
print = m =>
{
Console.WriteLine(m.Name);
m.ChildrenItems.ForEach(print);
};
print(rootItem);
}
Notice how it's necessary to declare print so that print can use itself. This is directly comparable to a recursive method, which I'd rather use:
public void PrintAllNames(RMenuItem rootItem)
{
Console.WriteLine(rootItem.Name);
rootItem.ChildrenItems.ForEach(PrintAllNames);
}
(although for a more complex situation, maybe the functional solution would make the most sense)
I suggest 2 ways of achieving this. You can opt with an utility method to get all the items or you can implement the Visitor Pattern, though it implies changing the RMenuItem class.
Utility method:
static IEnumerable<RMenuItem> GetAllMenuItems(IList<RMenuItem> items)
{
if (items == null)
throw new ArgumentNullException("items");
Queue<RMenuItem> queue = new Queue<RMenuItem>(items);
while (queue.Count > 0)
{
var item = queue.Dequeue();
if (item.ChildrenItems != null)
{
foreach (var child in item.ChildrenItems)
{
queue.Enqueue(child);
}
}
yield return item;
}
}
I prefer an imperative way to a recursive because we can use iterator blocks.
Visitor Pattern:
public interface IRMenuItemVisitor
{
void Visit(RMenuItem item);
}
public class PrintRMenuItemVisitor : IRMenuItemVisitor
{
public void Visit(RMenuItem item)
{
Console.WriteLine(item);
}
}
public interface IRMenuItem
{
void Accept(IRMenuItemVisitor visitor);
}
public class RMenuItem : IRMenuItem
{
// ...
public void Accept(IRMenuItemVisitor visitor)
{
visitor.Visit(this);
if (ChildrenItems != null)
{
foreach (var item in ChildrenItems)
{
item.Accept(visitor);
}
}
}
}
Usage:
RMenuItem m1 = new RMenuItem
{
Name = "M1",
ChildrenItems = new List<RMenuItem> {
new RMenuItem { Name = "M11" },
new RMenuItem {
Name = "M12",
ChildrenItems = new List<RMenuItem> {
new RMenuItem { Name = "M121" },
new RMenuItem { Name = "M122" }
}
}
}
};
RMenuItem m2 = new RMenuItem
{
Name = "M2",
ChildrenItems = new List<RMenuItem> {
new RMenuItem { Name = "M21" },
new RMenuItem { Name = "M22" },
new RMenuItem { Name = "M23" }
}
};
IList<RMenuItem> menus = new List<RMenuItem> { m1, m2 };
foreach (var menu in GetAllMenuItems(menus))
{
Console.WriteLine(menu);
}
// or
IList<RMenuItem> menus = new List<RMenuItem> { m1, m2 };
foreach (var menu in menus)
{
menu.Accept(new PrintRMenuItemVisitor());
}
You could difine a Flatten method in your class (or as an extension if you prefer) like this
public IEnumerable<RMenuItem> Flatten()
{
foreach (var item in ChildrenItems)
{
yield return item;
}
return ChildrenItems.SelectMany(item => item.Flatten());
}
then doing somthing with each elements will be as simple as
RMenuItem rootItem ;
// do somthing with the root item
foreach (var item in rootItem.Flatten())
{
// do somthing
}
Indeed you can do that using LINQ, SelectMany flats out the list, just some example
menuItemsList.SelectMany(x => x.ChildrenItems).Where(c => c.someChildProperty);
Thanks
Edit:
In response to the comments, I was just giving an example of SelectMany previously. Thanks for pointing out.
menuItemsList.SelectMany(x => x.ChildrenItems.Select(p => p)).Where(c => c.someChildProperty);
OR something like this
menuItemsList.SelectMany(x => x.ChildrenItems).Select(p => p).Where(c => c.someChildProperty);
Edit2
Ahh .. now I understood what you want ..
We can just slightly modify my above query to do what you want
menuItemsList
.SelectMany(x => { //do something with x like printing it
x.ChildrenItems
})
.Select(p => { // do something with p like printing it
p
});
Basically you can do what you want the element inside the {}
Thanks