Question 194573 in ASP.NET Question posted in
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Asp.net – Loop through Viewbags with a variable name

In my ASP.NET MVC View, I want to loop through Viewbag.A to ViewBag.Z but I’m not sure how to do this.

This is what I have in my view:

@{
    for (char letter = 'A'; letter <= 'Z'; letter++)
    {
        <h1 id=@letter>@letter</h1>       

        if (ViewBag.@letter != null)
        {
            foreach (var item in ViewBag.@letter))
            {
                 // do something here
            }
        }
    }
}

Is there a way to use a variable such as @letter in ViewBag name?

Tags:

4

Answers


  1. Chosen as BEST ANSWER
    0

    Thank you David for the clue. I stored all the values in a single ViewBag. Then in the view, I used StartsWith() to filter the results as below

    @{
for (char letter = 'A'; letter <= 'Z'; letter++)
{
    <h1 id=@letter>@letter</h1>


    if (ViewBag.F != null)
    {
        foreach (var item in ViewBag.F)
        {
            if (item.Title.StartsWith(@letter.ToString()))
            {
                //do something here
            }
        }
    }
}

    }

    Thank you all.


  2. 0

    Try this code man

    @{
    for (char letter = 'A'; letter <= 'Z'; letter++)
    {
        var propertyName = letter.ToString();
        <h1 id="@propertyName">@propertyName</h1>
        if (ViewBag is IDictionary<string, object> viewBagDict && viewBagDict.ContainsKey(propertyName))
        {
            var items = viewBagDict[propertyName] as IEnumerable<dynamic>;
            foreach (var item in items)
            {
                // Do something with each item here
                <p>@item</p>
            }
        }
    }
}
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  3. 0

    You can use reflection to enumerate the internal ViewDataDictionary of the ViewBag:

    @{
    var dc = ViewBag.GetType()
          .GetProperty("ViewData",
              System.Reflection.BindingFlags.Public |
              System.Reflection.BindingFlags.NonPublic |
              System.Reflection.BindingFlags.Instance)
          .GetValue(ViewBag, null);

    for (char letter = 'A'; letter <= 'Z'; letter++)
    {
        var s = letter.ToString();
        <h1 id=@letter>@letter</h1>
        if (dc[s] != null)
        {           
            //do something here          
        }
    }
}
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  4. 0

    I think better way to get your result would be to have a dictionary containing your ViewBag items and iterating through them that way, so your code would look something like this:

    public IActionResult SomeView()
{
   var dic = new Dictionary<char,YourClass>()
   //Populate your dictionary with your classes here
   //Where the character will be the key and the class will be the value
   ViewBag.ClassDic = dic;
   return View();
}

    And then your razor script will look something like this:

    @{
   foreach (KeyValuePair<char,YourClass> entry in ViewBag.ClassDic)
   {
       <h1 [email protected]>@entry.Key</h1>      
       foreach (var item in entry.Value))
       {
           // do something here
       }
   }       
}
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