Menu
  • HOME
  • TAGS

Get selected data

Tag: c#,asp.net,asp.net-mvc,asp.net-mvc-4

I already have the SQL Statement for retrieving data from the database, but I dont know how to pass the value from the class that I made to the controller and lastly to the view itself. I have tried to call the method for retrieving data from the database from the class that I made into the controller, and used ViewBag --> ViewBag.Name for save the value, and pass it to the view like this: @ViewBag.Name. When I run, there is nothing to show, like the method for retrieving data is not called.

My question is, how to pass the value from the database and put it into the view?

Here is the code that I am using:

Controller:

[HttpGet]
public ActionResult Update()
{
    ManageUser user = new ManageUser();

    user.GetData(user.Username);

    ViewBag.Username = user.Username;

    ViewBag.EmployeeID = user.EmployeeID;

    return View(user);
}

[HttpPost]
public ActionResult Update(ManageUser user)
{
    if (ModelState.IsValid)
    {
        if (user.UpdateData())
        {
            return RedirectToAction("List", "Home");
        }

        else
        {
            ModelState.AddModelError(string.Empty, "Cannot update to the database!");
        }
    }

    return View(user);
}

View:

@model ProjectName.Models.ManageUser
@{
    ViewBag.Title = "Update";
}

<h2>Update</h2>
<br />

@using (Html.BeginForm())
{
    @Html.ValidationSummary();

    <div>
        <fieldset>
            <legend>Credentials Register</legend>
            <div class="editor-label">
                @Html.LabelFor(u => u.Username)
            </div>
            <div class="editor-field">
                @ViewBag.Username
                @Html.DisplayFor(u => u.Username)
            </div>
            <div class="editor-label">
                @Html.LabelFor(u => u.EmployeeID)
            </div>
            <div class="editor-field">
                @ViewBag.EmployeeID
                @Html.DisplayFor(u => u.EmployeeID)
            </div>
            <input type="submit" value="Update &raquo;" />
            <input type="button" value="Cancel &raquo;" />
        </fieldset>
    </div>
}

Class (ManageUser.cs):

[Required(ErrorMessage = "Please fill-in Username.")]
[Display(Name = "Username:")]
public string Username
{
    get;
    set;
}

[Required(ErrorMessage = "Please fill-in Employee ID.")]
[Display(Name = "Employee ID:")]
public string EmployeeID
{
    get;
    set;
}
public void GetData(string username)
{
    using (SqlConnection conn = new SqlConnection(connectionString))
    {
        string query = "SELECT [Username], [EmployeeID] FROM [User] WHERE [Username] = @Username";

        conn.Open();

        using (SqlCommand cmd = new SqlCommand(query, conn))
        {
            cmd.Parameters.Add("@Username", SqlDbType.NVarChar);

            if (string.IsNullOrEmpty(Username))
            {
                cmd.Parameters["@Username"].Value = DBNull.Value;
            }

            else
            {
                cmd.Parameters["@Username"].Value = username;
            }

            using (SqlDataReader reader = cmd.ExecuteReader())
            {
                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        Username = reader["Username"].ToString();

                        EmployeeID = reader["EmployeeID"].ToString();
                    }
                }

                else
                {
                    reader.Dispose();

                    cmd.Dispose();
                }
            }
        }
    }
}

Best How To :

Firstly to address why no data is being loaded. In your Update() method you first initialize a new instance of ManageUser, whose default value for Username will be null (the default for typeof string). You then call user.GetData(user.Username); which passes null to the method and based on

if (string.IsNullOrEmpty(Username)) // it is!
{
  cmd.Parameters["@Username"].Value = DBNull.Value;
}

your query then returns all Users whose Username field is null. If you database does not contain any rows where Username IS NULL no rows are returned, therefor there is no data to display.

However including this method in your model is bad practice (and what about other methods such as fetching all users?). Start by adding the following 2 classes to your Data folder

public interface IUserDB
{
  List<User> Fetch();
  User Get(int ID);
}
public class UserDB : IUserDB
{
  public List<User> Fetch()
  {
    List<User> users = new List<User>();
    using (SqlConnection conn = new SqlConnection(connectionString))
    {
      string query = "SELECT [Username], [EmployeeID] FROM [User];
      conn.Open();
      using (SqlCommand cmd = new SqlCommand(query, conn))
      {
        using (SqlDataReader reader = cmd.ExecuteReader())
        {
          while (reader.Read())
          {
            User user = new User();
            user.Username = reader["Username"].ToString();
            user.ID = reader["EmployeeID"].ToString();
            users.Add(user);
          }
        }
      }
    }
    return users;
  }
  public User Get(int ID)
  {
    User user = new User();
    using (SqlConnection conn = new SqlConnection(connectionString))
    {
      string query = "SELECT [Username], [EmployeeID] FROM [User] WHERE [EmployeeID] = @ID";
      conn.Open();
      using (SqlCommand cmd = new SqlCommand(query, conn))
      {
        cmd.Parameters.Add("@EmployeeID", SqlDbType.Int).Value = ID;
        using (SqlDataReader reader = cmd.ExecuteReader())
        {
          if (!reader.Read())
          {
            return null;
          }
          user.ID = reader["EmployeeID"].ToString();
          user.UserName = reader["Username"].ToString();  
        }
      }
    }
    return user;
  }
}

Side notes: You do not need to call Dispose() - the using statement takes care of that. The purpose of the interface may not be obvious yet, but once you gain some experience and understand Dependency Injection it will be. Its not clear why a table named User would have a field named EmployeeID - it should be UserID or better, just ID. There is no need to call if (reader.HasRows).

Then change your class to

public class User
{
  [Required(ErrorMessage = "Please fill-in Username.")]
  [Display(Name = "Username:")]
  public string UserName { get; set; }

  [Required(ErrorMessage = "Please fill-in Employee ID.")]
  [Display(Name = "ID:")]
  public string ID { get; set; }
}

Notes: A class name should reflect what it is, not what is does - it should not contain verbs such as "Manage".

Now in the controller, you can can call these methods to construct your views

public Controller UserController : Controller
{
  UserDB _Repository = new UserDB(); // later you will use DI
  public ActionResult Index()
  {
    List<User> model = _Repository.Fetch();
    return View(model);
  }
  public ActionResult Edit(int ID)
  {
    User model = _Repository.Get(ID);
    if (model == null)
    {
      return new HttpNotFoundResult();
    }
    return View(model);
  }
}

Your Index.cshtml view might then look like

@model List<yourAssembly.User>
@foreach(var user in Model)
{
  @Html.ActionLink(user.UserName, "Edit", "User", new { id = user.ID }, null)
}

Clicking a a link will pass the users ID value to the Edit(int ID) method which in turn will return the User with that ID value.

Note also you Edit.cshtml view needs to include controls for editing, i.e @Html.TextBoxFor(m => m.UserName), not @Html.DisplayFor(m => m.UserName)

Visual Studio Assembly force-installs Target Framework

c#,.net,visual-studio-2013,.net-framework-version

The targeted .NET version is the only version that the app will depend upon by default. Visual Studio will not automatically add higher and backwards compatible releases. Do this manually by adding other .NET versions to a configuration file: On the Visual Studio menu bar: Choose Project; Add New Item;...

Foreign key in C#

c#,sql,sql-server,database

You want create relationship in two table Refer this link http://www.c-sharpcorner.com/Blogs/5608/create-a-relationship-between-two-dataset-tables.aspx...

Validate a field only if it is populated

c#,wpf,idataerrorinfo

You can implement your OptionalPhoneAttribute based on the original PhoneAttribute: public sealed class OptionalPhoneAttribute : ValidationAttribute { public override bool IsValid(object value) { var phone = new PhoneAttribute(); //return true when the value is null or empty //return original IsValid value only when value is not null or empty return...

Is it possible to concactenate a DataBound value with a constant string in XAML DataBinding?

c#,xaml,windows-phone

You can use a StringFormat in your binding, like so: <TextBox Text="{Binding ItemName, StringFormat={}Item: {0}}"/> That being said, it may cause some unexpected behavior when editing. For example, if the user edits only the item name (excluding the 'Item:' text), then when the TextBox loses focus, the string format will...

while Inherit style in WPF it affect parent style

c#,xaml,styles,wpf-controls

If you declare a Style without an x:Key, it will override the default style for that control. <Style TargetType="local:CustomControl"> So the code above will effect all CustomControl elements throughout the entire application (or within the scope). If you do not want to override the base style, you can give your...

How to declare var datatype in public scope in c#?

c#,linq

Declare it as a known type (not an anonymous type), like this for example: Dictionary<int, string> results = new Dictionary<int, string>(); Then you could store the results in the Dictionary: results = behzad.GAPERTitles.ToDictionary(x => x.id, x => x.gaptitle); And reference it later: private void button1_Click(object sender, EventArgs e) { //...

Difference between application and module pipelines in Nancy?

c#,asp.net,nancy

The module- and application pipelines are explained in detail in the wiki. It's basically hooks which are executed before and after route execution on a global (application pipelines) and per-module basis. Here's an example: If a route is resolved to a module called FooModule, the pipelines will be invoked as...

WCF service architecture query

asp.net,architecture,wcfserviceclient

As long as you are able to use the exact same contract for all the versions the web application does not need to know which version of the WCF service it is accessing. In the configuration of the web application, you specify the URL and the contract. However, besides the...

Get object by attribute value [duplicate]

c#,reflection,custom-attributes,spring.net

If you have obtained the Assembly, you can just iterate over the types and check for your conditions: var matchingTypes = from t in asm.GetTypes() where !t.IsInterface && !t.IsAbstract where typeof(ICustomInterface).IsAssignableFrom(t) let foo = t.GetCustomAttribute<FooAttribute>() where foo != null && foo.Bar == Y select t; I am assuming you want...

Catch concurrency exception in EF6 to change message to be more user friendly

c#,asp.net,.net,entity-framework,entity-framework-6

You are executing an asynchronous method. This means that any exceptions will be thrown when you call await on the returned task or when you try to retrieve the results using await myTask; You never do so, which means that the exception is thrown and caught higher up your call...

SQL Server / C# : Filter for System.Date - results only entries at 00:00:00

c#,asp.net,sql-server,date,gridview-sorting

What happens if you change all of the filters to use 'LIKE': if (DropDownList1.SelectedValue.ToString().Equals("Start")) { FilterExpression = string.Format("Start LIKE '{0}%'", TextBox1.Text); } Then, you're not matching against an exact date (at midnight), but matching any date-times which start with that date. Update Or perhaps you could try this... if (DropDownList1.SelectedValue.ToString().Equals("Start"))...

Aligning StackPanel to top-center in Canvas

c#,wpf,xaml,canvas

If you don't want any input or hit testing on a certain element you should set the IsHitTestVisible property to false: <Grid> <Canvas Name="Canvas" Background="#EFECCA"> <DockPanel VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Width="{Binding ActualWidth, ElementName=Canvas}" Height="{Binding ActualHeight, ElementName=Canvas}" MouseLeftButtonDown="DockPanel_MouseLeftButtonDown" TouchDown="DockPanel_TouchDown" Panel.ZIndex="2" Background="Transparent"> </DockPanel> <Button Width="50" Height="50"...

How to send Ctrl+S through SendKeys.Send() method to save a file(save as dialog)

c#,.net,windows,sendkeys

I believe you need to use: SendKeys.SendWait("^(s)"); Instead of: SendKeys.SendWait("^%s?"); Have a look at https://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.send(v=vs.110).aspx for more information....

deployment of a site asp.net and iis

c#,asp.net,iis

There are several domain providers like: godaddy, name etc you can use to buy a domain name. These providers also provide you steps to map the domain name to your website. Check out this link for example. This link explains domain name configuration in details.

Index was out of range. Must be non-negative or less than size of collection [duplicate]

c#

It looks like you have a typo in your loop condition: for (int index = filePaths.Count(); filePaths.Count() > 9; index--) It should be for (int index = filePaths.Count() - 1; index > 9; index--) Also note that for the first iteration of loop you're trying to access filePaths[filePaths.Count()] which is...

SettingsProvider class - should it be in DAL or BLL project?

c#,data-access-layer,bll

I don't agree that there is a right layer for you to put that class since you reading values from the config file based on keys provided and it can be needed by one or all of the layers. In the case of all layers using this class, you can...

how can I add a column to IQueryable object and modify its values

c#,.net,linq,grid,devexpress

Simple example for using a non-anonymous class. public class MyLovelyClass { public Int32 Number { get; set; } public bool Selection { get; set; } } var packs = from r in new XPQuery<Roll>(session) select new MyLovelyClass() { Number = r.number }; gcPack.DataSource = packs; ...

Convert contents of an XmlNodeList to a new XmlDocument without looping

c#,xml,xpath,xmldocument,xmlnodelist

If you're happy to convert it into LINQ to XML, it's really simple: XDocument original = ...; // However you load the original document // Separated out for clarity - could be inlined, of course string xpath = "//Person[not(PersonID = following::Person/PersonID)]" XDocument people = new XDocument( new XElement("Persons", original.XPathSelectElements(xpath) )...

How to Customize Visual Studio Setup

c#,visual-studio,setup-project

You can use a Microsoft Setup project or WIX (easily integrate with Visual Studio). Both are free. •You can do almost all of your customization in setup project by adding custom actions. •WIX (window installer xml) is the better option. You can do a complete customization from wix but it...

Update list of items in c#

c#,linq,list,updates

I would do something like this: (for ordinairy lists) // the current list var currentList = new List<Employee>(); currentList.Add(new Employee { Id = 154, Name = "George", Salary = 10000 }); currentList.Add(new Employee { Id = 233, Name = "Alice", Salary = 10000 }); // new list var newList =...

C# XML: System.InvalidOperationException

c#,xml

Is "User Info" and "Course Data" is a different entity. If it is so, I think you may encapsulate them in one entity. XmlTextWriter writer = new XmlTextWriter(path, System.Text.Encoding.UTF8); writer.WriteStartDocument(true); writer.Formatting = Formatting.Indented; writer.Indentation = 4; writer.WriteStartElement("My Entity"); /* It is a biggest one*/ writer.WriteStartElement("User Info"); writer.WriteStartElement("Name"); writer.WriteString(userName); writer.WriteEndElement(); writer.WriteStartElement("Tutor...

Export data from table in Pervasive

c#,pervasive

No, there is no way to export data programmatically through the "Export Data" wizard in the Pervasive Control Center. You would need to either write or have written an export module.

Error when building an XDocument

c#,xml,linq,xpath,linq-to-xml

You can ignore pretty much all your code, the issue is just this: XDocument people = new XDocument("Persons"); You can't create an XDocument containing a string, you need to add an element: XDocument people = new XDocument( new XElement("Persons", original.XPathSelectElements(xpathFilterDups))); ...

Multiple Threads searching on same folder at same time

c#,multithreading,file-search

Instead of using ordinary foreach statement in doing your search, you should use parallel linq. Parallel linq combines the simplicity and readability of LINQ syntax with the power of parallel programming. Just like code that targets the Task Parallel Library. This will shield you from low level thread manipulation and...

How do I provide a collection of elements to a custom attached property?

c#,wpf,binding

I managed to get it working using an IMultiValueConverter like this: public class BorderCollectionConverter : IMultiValueConverter { public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) { var borderCollection = new BorderCollection(); borderCollection.AddRange(values.OfType<Border>()); return borderCollection; } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture) { throw new...

C# Code design / Seperate classes for each TabControl

c#,oop,architecture,software-design,code-design

Place a UserControl on each tab.

Collect strings after a foreach loop

c#,xml,foreach

Yep, you need to do the adding within the loop. I'd use a List<string> as it supports LINQ: XmlNodeList skillNameNodeList=SkillXML.GetElementsByTagName("name"); List<string> skills = new List<string>(); foreach (XmlNode skillNameNode in skillNameNodeList) { skills.Add(skillNameNode.Attributes["value"].Value); } ...

How can I determine if an object of anonymous type is empty?

c#,.net

Anonymous types do not provide operator overloads for ==, although it wouldn't matter in this case since one of the arguments is typed object. However the C# compiler does provide Equals, GetHashCode, and ToString implementations. Use the static object.Equals, method which will do the appropriate null checks and then call...

check if file is image

c#,asp.net,asp.net-mvc

You can't do this: string.Contains(string array) Instead you have to rewrite that line of code to this: if (file == null || formats.Any(f => file.Contains(f))) And this can be shortened down to: if (file == null || formats.Any(file.Contains)) ...

How to return result while applying Command query separation (CQS)

c#,design-patterns,cqrs,command-query-separation

In such scenario I usually go with generating new entity Ids on the client. Like this: public class ProductController: Controller{ private IProductCommandService commandService; private IProductQueryService queryService; private IIdGenerationService idGenerator; [HttpPost] public ActionResult Create(Product product){ var newProductId = idGenerator.NewId(); product.Id = newProductId; commandService.AddProduct(product); //TODO: add url parameter or TempData key to...

Convert Date Time to IST

c#

You need to use "India Standard Time" instead of "Indian". Please refer to this link for a list of the time zone descriptions.

C# PCL HMACSHAX with BouncyCastle-PCL

c#,bouncycastle,portable-class-library

Try like this for HmacSha256 public class HmacSha256 { private readonly HMac _hmac; public HmacSha256(byte[] key) { _hmac = new HMac(new Sha256Digest()); _hmac.Init(new KeyParameter(key)); } public byte[] ComputeHash(byte[] value) { if (value == null) throw new ArgumentNullException("value"); byte[] resBuf = new byte[_hmac.GetMacSize()]; _hmac.BlockUpdate(value, 0, value.Length); _hmac.DoFinal(resBuf, 0); return resBuf; }...

C# - Can't connect to remote MySQL server

c#,mysql

When connecting to a MySQL-Database I always used the MySQL Connector you can get here: https://dev.mysql.com/downloads/connector/net/6.9.html You have to import the MySQL namespaces to your project and then you can use the MySQLConnection instead of the SQLConnection that is, as far as I know, only for MSSQL servers. http://www.codeproject.com/Tips/423233/How-to-Connect-to-MySQL-Using-Csharp...

How to make a website work only with https [duplicate]

asp.net,ssl,https

Sure, assuming you are using IIS to host your site, open IIS Manager and select your web site and then binding on the right: make sure you only have a binding for https not for http. This way IIS will only send https traffic to that web site. Edit: What...

Why is the task is not cancelled when I call CancellationTokenSource's Cancel method in async method?

c#,asynchronous,task,cancellationtokensource,cancellation-token

Cancellation in .Net is cooperative. That means that the one holding the CancellationTokenSource signals cancellation and the one holding the CancellationToken needs to check whether cancellation was signaled (either by polling the CancellationToken or by registering a delegate to run when it is signaled). In your Task.Run you use the...

Access manager information from Active Directory

c#,asp.net,active-directory

try this: var loginName = @"loginNameOfInterestedUser"; var ldap = new DirectoryEntry("LDAP://domain.something.com"); var search = new DirectorySearcher(ldap) { Filter = "(&(objectCategory=person)(objectClass=user)(sAMAccountName=" + loginName + "))" }; var result = search.FindOne(); if (result == null) return; var fullQuery = result.Path; var user = new DirectoryEntry(fullQuery); DirectoryEntry manager; if (user.Properties.PropertyNames.OfType<string>().Contains("manager")) { var managerPath...

Memory consumption when chaining string methods

c#,string,immutability,method-chaining

Is it true that when you chain string functions, every function instantiates a new string? In general, yes. Every function that returns a modified string does so by creating a new string object that contains the full new string which is stored separately from the original string. There are...

Regex that allow void fractional part of number

c#,regex

Just get the dot outside of the captruing group and then make it as optional. @"[+-]?\d+\.?\d*" Use anchors if necessary. @"^[+-]?\d+\.?\d*$" ...

Regex to remove `.` from a sub-string enclosed in square brackets

c#,.net,regex,string,replace

To remove all the dots present inside the square brackets. Regex.Replace(str, @"\.(?=[^\[\]]*\])", ""); DEMO To remove dot or ?. Regex.Replace(str, @"[.?](?=[^\[\]]*\])", ""); ...

System.net.http.formatting causing issues with Newtonsoft.json

c#,asp.net,asp.net-mvc,json.net

Does the assemblyBinding tag have proper xmlns schema? Check if the issue you are encountering is same as Assembly binding redirect does not work

Load XML to list using LINQ [duplicate]

c#,xml,linq

Make a base class which will have id,x,y,z, and have Vendors,Bankers and Hospitals extend it. Then you can have a collection of the base class, and add to it the classes that inherit from it....

Marshal struct in struct from c# to c++

c#,c++,marshalling

Change this: [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 36)] private string iu; to this: [MarshalAs(UnmanagedType.LPStr)] private string iu; Note that this code is good only to pass a string in the C#->C++ direction. For the opposite direction (C++->C#) it is more complex, because C# can't easily deallocate C++ allocated memory. Other important thing:...

Unconstrained type parameters casting

c#,.net,types,casting

The compiler sees the T2 and T identifiers and helpfully informs you that those types seem unrelated. That's absolutely correct, as they have no relation: there are no generic constraints that would assert any relations between them (I'm not saying that would be useful here though :) ). Whether this...