Showing data by percentage on Pie Charts in MVC

问题:

In my MVC5 application I have table lets's say it's name is Student and every student belonging to a Team. I want to show students according to their teams by percentage. For this reason I also created a ViewModel in order to join Student entity with Team entity. So, how can I show the data I want on Kendo UI pie chart? Could you have a look at the code and correct the mistakes below? And could you give a View samples suitable to this approach? Thanks in advance.

ViewModel:

public class StudentViewModel
{
    public int StudentId { get; set; }

    public int TeamId { get; set; }

    public string TeamName { get; set; }

    public int TeamPercentage { get; set; }
}

Controller:

public ActionResult Index_Read([DataSourceRequest] DataSourceRequest request)
{
    var dataContext = repository.Student;

    var result = dataContext.ToDataSourceResult(request, m => new StudentViewModel
        {
            StudentId = m.StudentId,
            TeamId = m.TeamId,
            TeamName = m.TeamName,

            TeamPercentage = //??? How can I obtain percentage by Lambda Expression ???
        }
    );
    return Json(result, JsonRequestBehavior.AllowGet);
}

回答1:

You could do something like this:

Viewmodel

public class StudentViewModel
{
    public string category { get; set; }
    public int value { get; set; }
}

Controller (note I've made some assumptions in the query)

public ActionResult Index_Read()
{
    var teamCount = repository.Team.Count();
    var result = repository.Student.GroupBy(g => g.TeamName).Select(s => new StudentViewModel { category = s.Key, value = s.Count()/teamCount });
    // Imagine result contains something like this: { category = "Team 1", value = "20" }, { category = "Team 2", value = "30" }, { category = "Team 3", value = "10" }, { category = "Team 4", value = "40" }
    return View(result);
}

View

@model IEnumerable<StudentViewModel>

@(Html.Kendo().Chart()
    .Name("chart")
    .Title(title => title.Text("Teams").Position(ChartTitlePosition.Bottom))
    .Legend(legend => legend.Visible(true))
    .Series(series => series.Pie(Model))
)

Alternative

Another way to do it would be using a data source binding.

public class StudentViewModel
{
    public string TeamName{ get; set; }
    public int Percentage { get; set; }
}

@(Html.Kendo().Chart<StudentViewModel>()
    .Name("chart2")
    .DataSource(ds => ds.Read("GetTeamData", "Home"))
    .Series(series => series.Pie(m => m.Percentage, model => model.TeamName))
)