I am new in c# and MVC and this is my question:
For my new website, I would like to have a DropDownList in my header so the visitors can choose a Currency.
I have a SQL server table named CurrencyList
I have a Controller named BaseController : Controller
I have a model:
public partial class CurrencyList
{
public int CurrencyId { get; set; }
public string CurrencyName { get; set; }
public string CurrencySymbol { get; set; }
public Nullable<decimal> CurrencyValue { get; set; }
public string Currency { get; set; }
public Nullable<System.DateTime> LastUpdate { get; set; }
}
Now, how do I get the datas in the select? And how do I manage the Post?
For my select, I will use only the field Currency, and by default EUR will be selected.
Onchange, I would like to save the Currency value in a session and/or cookie.
Thanks in advance.
You can use Ajax Get method to call the method of controller which get data for bind dropdown list
Related
Good day!
I'm having an issue with the DevExpress LookUpEdit I can't figure out what the problem is.
I'm use Entity Framework list as a datasource.
public partial class provider_scheme : BaseEntity
{
public provider_scheme()
{
}
public int Provider_Scheme_RowID { get; set; }
public int Currency_RowID { get; set; }
public string Provider_Scheme_Name { get; set; }
public virtual currency currency { get; set; }
}
public partial class currency : BaseEntity
{
public currency()
{
provider_scheme = new HashSet<provider_scheme>();
}
public int Currency_RowID { get; set; }
public string Currency_ISOCode { get; set; }
public virtual ICollection<provider_scheme> provider_scheme { get; set; }
}
I'm setting the Datasource property of the LookUpEdit to IEnumerable<provider_scheme>, and setting up two column field names in my LookUpEdit. One for 'Provider_Scheme_Name' and one for 'currency.Currency_ISOCode'. But for some reason only the 'Provider_Scheme_Name' column values are showing. I've also checked and the 'currency' navigation property is being loaded.
Thanks in advance for your help
A bit late for an answer, but you might consider using the GridLookupEdit control instead. It permits adding all the columns you want
I'm trying to run a query that gets all of my references, but it isn't working.
What I have right now is
from UserGroups
where Id="ActionGroup"
select Accomplishments.ID, Accomplishments.Accomplish
But I need only the Accomplishments.Accomplish that belong in my other collection ActivityAccomplishments and these are nested in another object.
To be exact, I'm trying to figure out how to query the UserGroups collection and only look at the one with id="ActionGroup". After that I need all of the Accomplishments.Accomplish strings within the UserGroup list to be filtered out if they don't match a id in ActivityAccomplishment.
Basically, in the UserGroup I'm looking at it's List Accomplishments needs to filter out all strings within the Acc class that don't match an Id in ActivityAccomplishments. Can someone please help me.
Here are the classes I'm using.
public class UserGroups
{
public string Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public List<Acc> Accomplishments { get; set; }
}
public class Acc
{
public string Id { get; set; }
public List<string> Accomplish { get; set; }
}
public class ActivityAccomplishments
{
public string Id { get; set; }
}
try this:
from UserGroups
where Id = "ActionGroup" AND Accomplishments[].Accomplish != "theIdYouDontWant"
select Accomplishments[].Accomplish as AccomplishStringsList
(not necessary to add the 'as AccomplishStringsList' - it is just a name for the results)
I'm making a task management tool using AngularJS for the frontend and ASP.NET WEB API 2 for the backend. I have two entities in the database, a "Task" and a "Type". Each task has one type associated. The user fills a form when he can create a new task, and he has to select a type for that task.
Here's the C# code:
// KBTM_Task.cs file
public class KBTM_Task
{
public int ID { get; set; }
public string TaskID { get; set; } // User defined ID
public string Title { get; set; }
public string Description { get; set; }
}
// KBTM_Type.cs file
public class KBTM_Type
{
public int ID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
}
So my question is: how do I "connect" the two in the database? What I mean is, let's say I want to POST data to the database. I have to make two POSTs, right? One for the Task and one for the Type, since they're two separate entities.
But since they're stored with two different IDs, how do I know that a certain task has a certain type? In other words, if I send a GET request to KBTM_Task, how do I get the type of that task?
Modify your KBTM_Task entity to include the Type Id and foreign key relationship
public class KBTM_Task
{
public int ID { get; set; }
public string TaskID { get; set; } // User defined ID
public string Title { get; set; }
public string Description { get; set; }
public int TypeID { get; set; }
[ForeignKey("TypeID")]
public virtual KBTM_Type Type { get; set; }
}
This way when you get the data from the API your task object will already include the key ("TypeID") that can be updated and related object ("Type") that you can access its properties (Name, Description, ...).
When you update TypeID on the client object (model) you can simply push the updated task object to the API using $http.put() to handle the database update.
1) Add foreign key using fluent api (or data annotation)
// KBTM_Task.cs file
public class KBTM_Task
{
public int ID { get; set; }
public string TaskID { get; set; } // User defined ID
public string Title { get; set; }
public string Description { get; set; }
public int KBTM_TypeID {get;set}
public virtual KBTM_Type {get; set}
}
// KBTM_Type.cs file
public class KBTM_Type
{
public int ID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public KBTM_Task KBTM_Task { get; set;}
}
Add the following in the class inheriting from DbContext
public class KbtmContext : DbContext
{
...
//public virtual DbSet<KBTM_Task> KbtmTasks {get; set;}
...
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// Configure KBTM_TypeID as FK for KBTM_Task
modelBuilder.Entity<KBTM_Task>()
.HasRequired(k => k.KBTM_Type)
.WithRequiredPrincipal(ad => ad.KBTM_Task);
}
}
2) If exposing the entity class in API response or request then you need to exclude navigation property from being serialized.
// KBTM_Task.cs file
public class KBTM_Task
{
...
[JsonIgnore]
public virtual KBTM_Type Type { get; set; }
}
To use the [JsonIgnore] atttribute use Install-Package Newtonsoft.Json in package manager console.(One of the popular solutions to manage serialization)
public partial class User
{
public System.Guid UserId { get; set; }
public Nullable<System.Guid> RoleId { get; set; }
public Nullable<long> MembershipNo { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Gender { get; set; }
public string Emaiil { get; set; }
public Nullable<decimal> MobileNo { get; set; }
public string Description { get; set; }
public Nullable<System.Guid> ModifiedBy { get; set; }
public Nullable<System.DateTime> ModifiedDate { get; set; }
public virtual Role Role { get; set; }
}
This is my table in DB named Users which is associated with Roles table of DB (as you can see last virtual row at the end above)
Now My problem is simple. I'm using angulars $http.get() method to call my Web Api in MVC 4. When i call it, it gets connected and fetches desired record but it doesn't throw proper result back to .js file or controller.
At .js side I run into error. Every time, it executes .error(jsonResult,config,header,status) .
When I jump on to JsonResult, it shows me below error.
Object
ExceptionMessage: "The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'."
ExceptionType: "System.InvalidOperationException"
InnerException: Object
ExceptionMessage: "Self referencing loop detected for property 'Role' with type
'System.Data.Entity.DynamicProxies.Role_82CA96EA045B1EB47E58B8FFD4472D86502EEA79837B4AE3AD705442F6236E58'.
Path 'Role.Users[0]'."
ExceptionType: "Newtonsoft.Json.JsonSerializationException"
Message: "An error has occurred."
I don't know what's wrong here. Is it json parsing error or something? if so, I've heard and read the articles that webapi in .net handles or throws json itself.
My call happens through
$http.get(apiUrl).success(function (jsonResult, header, config, status) {
debugger;
var number = parseInt(jsonResult.membershipNo) + 1;
$scope.membershipNo = "M" + number;
})
.error(function (jsonResult, header, config, status) {
debugger;
toastr.error('Something went wrong ! Contact Administrator!!!');
});
Edited:
One more thing to mention, .CS side when I fetch single cell value (from DB/table) , it gets returned back to .success() call but when i fetch particular row or all rows, it gets returned to .error() call. I'm using entity frameworkd 6.1.1. and above class is generated by EF-6.1.1.
public partial class Role
{
public Role()
{
this.Permissions = new List<Permission>();
this.Users = new List<User>();
}
public System.Guid RoleId { get; set; }
public string RoleName { get; set; }
public string Description { get; set; }
public Nullable<System.Guid> ModifiedBy { get; set; }
public Nullable<System.DateTime> ModifiedDate { get; set; }
public virtual ICollection<Permission> Permissions { get; set; }
public virtual ICollection<User> Users { get; set; }
}
Hi you can solve that in 2 easy steps
First Step: Create globalConfig class where you can set ignoring ReferenceLoopHandling (http://james.newtonking.com/json/help/index.html?topic=html/SerializationSettings.htm) and if you crating js app you can set as well to remove xml formaters and always get return from Webapi as JSON string is usefull for debugging. So in your app_start folder add class GlobalConfig like below:
public class GlobalConfig
{
public static void CustomizeConfig(HttpConfiguration config)
{
// Remove Xml formatters. This means when we visit an endpoint from a browser,
// Instead of returning Xml, it will return Json.
//that is optional
config.Formatters.Remove(config.Formatters.XmlFormatter);
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling =
Newtonsoft.Json.ReferenceLoopHandling.Ignore;
}
}
Second Step: In Global.asax set your custom configuration to do that please add code below to method Application_Start():
GlobalConfig.CustomizeConfig(GlobalConfiguration.Configuration);
it sounds like:
the problem is that EF is using lazy loading that is not materialized in time of constructing this, on role. EF from early version has switched lazy loading on by default.
Suggested solution
Create subset of you user class, with the parts that you really need.
=> Its bad practise to fetch too much data that you are not gonna need.
I'm having some doubts, maybe newbie doubts but I just got into ASP.NET MVC 4
Basically I would like to know the correct way of grabbing details of an Object inside a model.
In this case Image inside Contractor.
Model:
public class Contractor {
[Key]
public int ContractorID { get; set; }
[Required]
public string Name { get; set; }
[Required]
public string Address { get; set; }
public Image Avatar { get; set; }
}
public class Image {
[Key]
public int ImageID { get; set; }
[Required]
public string File_name { get; set; }
[Required]
public byte[] File_data { get; set; }
}
public class DATACRUD : DbContext {
public DbSet<Contractor> Companies { get; set; }
public DbSet<Image> Images { get; set; }
}
Controller:
private DATACRUD db = new DATACRUD();
public ActionResult GetContractorAvatar(int id)
{
Contractor contractor = db.Contractors.Find(id);
if (contractor == null)
{
return HttpNotFound();
}
Image avatar = contractor.Avatar;
Problem 1)
avatar == null, but is not suppose to be because when I created the object Contractor, I added the image sucessfully (I checked in the DB and it is there)
The solution I'm seeing is instead of having Image property in Contractor.cs model, I would just put a string property with the image key.
Problem 2)
Even If could grab the image key like I said in the previous problem, when I pass my mouse in Debug mode over
private DATACRUD db = new DATACRUD ();
db.Images is also empty...
return File(avatar.File_data, "image");
}
Because you haven't defined your Image navigation property as virtual, you will have to eager load the Image when loading a Contractor:
db.Contractors.Include("Avatar").SingleOrDefault(c => c.ContractorID == id);
OR
// using System.Data.Entity;
db.Contractors.Include(c => c.Avatar).SingleOrDefault(c => c.ContractorID == id);