如何使用LINQ查询ASP.NET MVC 5实体框架来填充视图模型 [英] How to populate a view models using a linq query ASP.NET MVC 5 Entity Framework
问题描述
好了，所以这是从<一个后续href=\"http://stackoverflow.com/questions/30610141/mvc-5-asp-net-entity-framework-collect-form-data-through-range-input/30616463?noredirect=1#comment49333564_30616463\">MVC 5 ASP.NET实体框架通过范围输入收集表单数据，我的数据库结构由一个调查有很多类别，类别有很多问题，然后有很多QuestionResults最后一个问题QuestionResults有很多CategoryResults，在HomeController的我必须通过视图模型绑定的车型，但我现在要求它通过使用LINQ的背景下与我的实体填充，任何帮助将大大AP preciated。
Ok so this is a follow-up from MVC 5 ASP.NET Entity Framework Collect Form Data through Range Input , My Database Structure Consists of a Survey Having Many Categories, A Category having many Questions, then a Question having many QuestionResults and finally QuestionResults having many CategoryResults, in the HomeController I have the models being bound through the ViewModel, but I now require it to be populated with my entities through the context with Linq, any help will be greatly appreciated.
我需要填充这个视图模型，这与一个非常有价值的堆栈溢出贡献者的帮助下创建的，用我的实体，所有code是如下：
I need to populate this ViewModel, which was created with the help of a very valuable stack-overflow contributor, with my Entities, all code is as below:
主要问题：？我如何能带来我的实体到我SurveyVM视图模型的实例
视图模型
namespace MyApp
{
public class SurveyVM
{
public int ID { get; set; }
public string Name { get; set; }
public List<CategoryVM> Categories { get; set; }
}
public class CategoryVM
{
public int ID { get; set; }
public string Name { get; set; }
public List<QuestionVM> Questions { get; set; }
}
public class QuestionVM
{
public int ID { get; set; }
public string Title { get; set; }
public int Score { get; set; }
}
public class QuestionResult
{
public int ID { get; set; }
public int QuestionId { get; set; }
public int QuestionScore { get; set; }
}
}
链接到实体和随后的数据库模型
public class Question
{
public int Id { get; set; }
public string Title { get; set; }
public string CreatedBy { get; set; }
public DateTime? DateCreated { get; set; }
public DateTime? DateModified { get; set; }
public virtual Category Category { get; set; }
public int CategoryId { get; set; }
public virtual ICollection<QuestionResult> QuestionResult { get; set; }
public virtual ICollection<QuestionFeedback> QuestionFeedback { get; set; }
}
public class QuestionResult
{
public int Id { get; set; }
public DateTime? DateCreated { get; set; }
public DateTime? DateModified { get; set; }
public int QuestionScore { get; set; }
//navigation properties
public virtual ApplicationUser User { get; set; }
public ICollection<CategoryResult> CategoryResult { get; set; }
public virtual Question Question { get; set; }
public int QuestionId { get; set; }
}
public class CategoryResult
{
public int Id { get; set; }
public int CategoryScore {get;set;}
//navigation properties
public virtual QuestionResult QuestionResult { get; set; }
public int QuestionResultId { get; set; }
}
public class Category
{
public int Id { get; set; }
public string Title { get; set; }
public string CreatedBy { get; set; }
public DateTime? DateCreated { get; set; }
public DateTime? DateModified { get; set; }
public virtual Survey Survey { get; set; }
public int SurveyId { get; set; }
public virtual ICollection<Question> Question { get; set; }
public virtual ICollection<CategoryFeedback> CategoryFeedback { get; set; }
}
的HomeController
public ActionResult IndexSurveyViewModel()
{
SurveyVM model = new SurveyVM()
{
ID = 1,
Name = "Survey 1",
Categories = new List<CategoryVM>()
{
new CategoryVM()
{
ID = 1,
Name = "Category A",
Questions = new List<QuestionVM>()
{
new QuestionVM()
{
ID = 1, Title = "Question 1A", Score = 2
},
new QuestionVM()
{
ID = 2, Title = "Question 2A", Score = 4
}
}
},
new CategoryVM()
{
ID = 1,
Name = "Category B",
Questions = new List<QuestionVM>()
{
new QuestionVM()
{
ID = 3, Title = "Question 1B", Score = 3
},
new QuestionVM()
{
ID = 4, Title = "Question 2B", Score = 5
}
}
},
new CategoryVM()
{
ID = 1,
Name = "Category C",
Questions = new List<QuestionVM>()
{
new QuestionVM()
{
ID = 5, Title = "Question 1C", Score = 1
},
new QuestionVM()
{
ID = 6, Title = "Question 2C", Score = 3
}
}
}
}
};
return View(model);
}
[HttpPost]
public ActionResult IndexSurveyViewModel(SurveyVM model)
{
List<QuestionResult> results = new List<QuestionResult>();
foreach (CategoryVM category in model.Categories)
{
foreach (QuestionVM question in category.Questions)
{
results.Add(new QuestionResult()
{
Id = question.ID,
QuestionScore = question.Score
});
}
}
return View(model);
}
查看
@model STRA.Models.SurveyVM
@{
Layout = null;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>My app</title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.11.4/themes/smoothness/jquery-ui.css">
<style>
.category {
display: none;
margin-left: 20px;
margin-top: 10px;
}
.category:first-of-type {
display: block;
}
.category:first-of-type button:last-of-type {
display: none;
}
.category:last-of-type button:first-of-type {
display: none;
}
.question {
margin-left: 20px;
margin-top: 10px;
}
.buttons {
margin: 20px;
}
input[type="text"] {
width: 20px;
}
.slider {
display: inline-block;
width: 200px;
margin-left: 20px;
}
</style>
</head>
<body>
@using (Html.BeginForm())
{
@Html.HiddenFor(m => m.ID)
@Html.DisplayFor(m => m.Name)
for (int i = 0; i < Model.Categories.Count; i++)
{
<div class="category">
@Html.HiddenFor(m => m.Categories[i].ID)
@Html.DisplayFor(m => m.Categories[i].Name)
@for (int j = 0; j < Model.Categories[i].Questions.Count; j++)
{
<div class="question">
@Html.HiddenFor(m => m.Categories[i].Questions[j].ID)
@Html.DisplayFor(m => m.Categories[i].Questions[j].Title)
@Html.TextBoxFor(m => m.Categories[i].Questions[j].Score)
<div class="slider"></div>
</div>
}
<div class="buttons">
<button type="button" class="next">Next</button>
<button type="button" class="previous">Previous</button>
</div>
</div>
}
<input type="submit" />
}
<!-- JS includes -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="//code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
<script type="text/javascript">
$('.slider').each(function() {
var v = $(this).closest('.question').find('input[type="text"]').val();
$(this).slider({
value: v,
min: 1,
max: 5,
change: function (event, ui) {
$(this).closest('.question').find('input[type="text"]').val(ui.value);
}
});
});
$('.next').click(function() {
$(this).closest('.category').hide().next('.category').show();
});
$('.previous').click(function() {
$(this).closest('.category').hide().prev('.category').show();
});
</script>
</body>
</html>
我的code迄今：
var survey = from s in db.Surveys
from c in db.Categories
from q in db.Questions
where s.Id == c.SurveyId
where c.Id == q.CategoryId
select new SurveyVM
{
ID = s.Id,
Name = s.Title,
Categories = new List<CategoryVM>()
{
new CategoryVM()
{
ID = c.Id,
Name = c.Title,
Questions = new List<QuestionVM>()
{
new QuestionVM()
{
ID = q.Id,
Title = q.Title
}
}
}
}
};
我怎样才能把我的实体到我SurveyVM视图模型实例吗？
How can I bring in my entities into my SurveyVM ViewModel instance?
推荐答案
本，其使用lambda前pressions可能指向你在正确的方向。
This might point you in the right direction, its using lambda expressions.
List<SurveyVM> surveys = DbContext.Survey.Select(s=> new SurveyVM {
ID = s.ID,
Name = s.Name,
Categories = s.Category.Select(c => new CategoryVM {
ID = c.ID,
Name = c.Name,
Questions = c.Question.Select(q=> new QuestionVM {
ID = q.ID,
Title = q.Title,
Score = q.Score
}).ToList()
}).ToList()
}).SingleOrDefault();
这是我的头顶部，我没有任何东西来测试它。
This is off the top of my head as I dont have anything to test it with.
另外，作为一个方面说明我会看看使用EditorTemplates / DisplayTemplates，而不是你的循环在你的视图它会使你code更容易阅读。
Also as a side note I would look at using EditorTemplates/DisplayTemplates instead of your loop in your view as it will make your code easier to read.
for (int i = 0; i < Model.Categories.Count; i++)
{
<div class="category">
@Html.HiddenFor(m => m.Categories[i].ID)
@Html.DisplayFor(m => m.Categories[i].Name)
@for (int j = 0; j < Model.Categories[i].Questions.Count; j++)
{
<div class="question">
@Html.HiddenFor(m => m.Categories[i].Questions[j].ID)
@Html.DisplayFor(m => m.Categories[i].Questions[j].Title)
@Html.TextBoxFor(m => m.Categories[i].Questions[j].Score)
<div class="slider"></div>
</div>
}
<div class="buttons">
<button type="button" class="next">Next</button>
<button type="button" class="previous">Previous</button>
</div>
</div>
}
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