Following is the Observable collection which is available in the viewmodel:
ObservableCollection<Category> productcat;
further split of Category class is as follows:
public class Category
{
public string CategoryName { get; set;}
public List<ProductData> Products
{
get;
set;
}
}
ProductData class as follows:
public class ProductData
{
public string ProductImageUri { get; set;}
public string ProductTitle { get; set;}
public float productcost { get; set;}
}
Part 1:
Now I have UIScrollView where each Scrollbar item is a button item, containing title as the CategoryName.
I want to do the binding of CategoryName from the observable collection- to each scrollbar button title
Whenever the collection changes the buttons in the UISCrollView titles must reflect the change. What would be the binding expression in this case given the above class structures. Its challenging to figure out binding syntax.
Part 2:
I have a UITableView which would contain a cell having product title, product image and product cost, which means i have list
I want to bind this UITableView to this list which is part of Observable Collection->CategoryName->ProductData list
What would be the binding expression in this case. I hope we must do custom binding here.?
Yes as you said MvxTableViewCell etc., are available.
And regarding custom binding should I do it in the minisetup?
view models/data structures
In your data structures, you seem to be binding public fields instead of public properties.
These won't work straight away - you need to use properties
So:
public string CategoryName;
public class ProductData
{
public string ProductImageUri;
public string ProductTitle;
public float productcost;
}
need to become:
public string CategoryName {get;set;}
public class ProductData
{
public string ProductImageUri {get;set;}
public string ProductTitle {get;set;}
public float productcost {get;set;}
}
I am not able to find any of these classes: MvxCollectionViewSource, MvxTableViewCell, MvxCollectionViewController etc
MvxCollectionViewSource and MvxTableViewCell should be available in MvvmCross.Binding.Touch.dll
MvxCollectionViewController is not available - it's an MvvmCross View
In this case how can I achieve binding in CrossCore environment?
This is shown in the N+1 N=39 tutorial - http://slodge.blogspot.com.au/2013/09/n39-crosslight-on-xamariniosmonotouch.html - with source in https://github.com/slodge/NPlus1DaysOfMvvmCross/tree/master/N-39-CrossLight-Touch
Also I should be able to do custom bindings?
Yes
But I am not having any setup class.. in my case. How can achieve custom binding in this case?
As shown in the N+1 N=39 tutorial, you still have a setup class - so you can put your initialization code in there. After the binding builder has been initialized, you can access the IMvxTargetBindingFactoryRegistry using Mvx.Resolve<IMvxTargetBindingFactoryRegistry>()
Because you are not using MvvmCross - because you are choosing to build your own framework - then ensuring setup is done is your own job to do.
What I am currently doing is have a view class and derive the view from IMvxBindable that's all and doing some binding in it
I have no idea what this means - please try including a working code sample in your questions.
Related
First of all I am talking about WinForms projects on Win10 and not ASP.NET in case somebody feels inclined to answer for ASP.NET.
Now, I will be using Entity Framework with code-first approach, I have used that in the past a lot with SQL & SQL Lite.
My question is, what if I don't want to use SQL/Lite as backend but use JSON? I noticed a nice WPF application storing all its relational data in a JSON file but I can't seem to find anything regarding using JSON as my backend RDBMS. It won't be a large database, but it is definitely relational data.
I use Entity Framework, Winforms, .NET and C#. I would like to have something like this:
class Top {
public int ID {get;set;}
public string Title {get;set;}
public TagInfo MainTag {get;set;}
public HashSet<TagInfo> TagCatalog {get;set;}
}
class TagInfo {
public int ID {get;set;}
public string TagName {get;set;}
public Color TagColor {get;set;}
public DogInfo Dog {get;set;}
}
class DogInfo {
public int ID {get;set;}
public string DogName {get;set;}
public Color DogColor {get;set;}
}
What I say is that when I serialize Top I don't want the Top.MainTag to be serialized as the full TagInfo but only its ID because all the tag information is already on the TagCatalog property.
You don't need EF for that. Just use a JSON serializer to save and load a bunch of objects to a file.
I am having an issue while trying the WebAPI of net core.
For some reason my object always comes empty no matter what I try. I've checked several other SO questions regarding this but cannot find a solution for what I am facing.
My model:
My controller (getting the null object):
And the POSTMAN request:
I've tried both with and without the [FromBody] option as I've seen in other SO questions that some people solved their issues with it.
Any ideas?
All the auto-implemented properties must have an public modifier before them to for JSON.NET to safely deserialize them.
public class APIRequest
{
string Action { get; set; }
}
Because in the above example no access modifier is given, thereby making it as private, so the default value of the property is assigned which is default(string) that is null.
public class APIRequest
{
public string Action { get; set; }
}
By default all class members are private and the class itself is internal, so you have to mark your property with public modifier.
We are developing a single page app using ASP.NET MVC4 with Web Api + Ko + Breeze using EF Code First.
Our (simplified) data model looks like this
class Product {
public String Name { get; set; }
public ICollection<ImageCollection> ImageSets { get; set;}
public Image DefaultImage { get; set; }
}
class ImageCollection {
public ICollection<Image> Images { get; set; }
}
class Image {
public String ImageUrl { get; set; }
}
DefaultImage is a navigation property (with foreign key) and is one of the images in the ImageSets.
We are exposing a Web API method of Products() and with default Breeze configuration. JSON serialized output on the wire has references for objects (i.e., PreserveReferencesHandling.Object) so when I want to bind the ImageUrl ko is unable to resolve the value.
Html looks like this
<img data-bind="attr: { src: DefaultImage().ImageUrl, title: Name}" />
When I switch the serializer to do PreserveReferencesHandling.None, the binding works.
Question: how do I make the default config to work? or if I switch to PreserveReferencesHandling.None for Breeze what are the gotchas/downsides?
Thanks!
In general, you do NOT want to switch PreserveReferencesHandling to None because you will lose the ability to serialize circular references and your payloads will get much larger.
I don't actually understand why your binding would begin to work after setting this. The first step to understanding this is probably to check that the ko objects actually contain the correct data after your query.
Remember that breeze navigation properties are lazy-loaded, so you may not have loaded them with your initial query. Take a look at the "EntityAspect.loadNavigationProperty" method.
Another 'Entity Type 'x' has no key defined' question, but I've set the [Key] attribute on a property so I'm a bit confused.
Here's my entity and context classes:
namespace DoctorDB.Models
{
public class Doctor
{
[Key]
public string GMCNumber;
[Required]
public string givenName;
[Required]
public string familyName;
public string MDUNumber;
public DateTime MDUExpiry;
public string MDUCover;
}
public class DoctorContext : DbContext
{
public DbSet<Doctor> Doctors { get; set; }
}
}
When I go to create my controller, I've selected to create it with the Entity Framework methods using this entity and context:
and I get this error:
My only thought is whether you can't successfully use [Key] on a string property. If you can't then fair enough, I'll work round it, but I'd be grateful if someone could confirm this one way or the other.
You need to change GMCNumber to a property not a field.
To help clarify, this line:
public string GMCNumber;
needs to become:
public string GMCNumber { get; set; }
I encountered the same error message when I had defined the property as private.
I ran into this post after facing a similar issue today. The problem was that I was attempting to create the scaffold after adding the [Key] attribute to my model and without compiling. Once I compiled with the [Key] attribute the scaffolding generated just fine.
I am attempting to implement a tagging system into my asp.net MVC project. When a user edits or adds a task, they can add any amount of tags they want before submitting. I am using the Jquery Tagit plugin, so when a user adds a new tag an input field is created that looks like:
<input type="hidden" style="display:none;" value="tag1" name="Tags[]">
When the user presses the submit button after adding a few tags, the browser sends the following querystring to the server (retrieved via fiddler):
IsNew=True&Id=2222&Title=Test+Title&Description=Test+Description&Tags%5B%5D=Tag1&Tags%5B%5D=blah&Tags%5B%5D=another-tag
Now my viewmodel that I am serializing this data into has the following structure:
public class KnowledgeBaseTaskViewModel
{
public int Id { get; set; }
[Required(AllowEmptyStrings=false, ErrorMessage="Task title is required")]
[StringLength(500)]
public string Title { get; set; }
[Required(AllowEmptyStrings=false, ErrorMessage="Task description is required")]
[StringLength(500)]
public string Description { get; set; }
public List<string> Tags { get; set; }
public bool IsNew { get; set; } // Needed to determine if we are inserting or not
}
Finally my receiving action has the following signature:
[HttpPost]
public ActionResult EditTask(KnowledgeBaseTaskViewModel task)
The issue is that my tag list is not serializing correctly, and my List Tags is null. I have looked at various questions on this site on how to serialize arrays but I still cannot see what I am doing wrong. Any help is greatly appreciated.
It sounds like what you've got should work, but try changing the type of Tags property from List to IList. the model binder might not be using the concrete List<> type.
also, check out this article by Phil Haack: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx