Dropdown asp net core set selected item

Introduction

ASP.NET is a popular programming language used for building web applications. One common requirement in web development is to have a dropdown list with a pre-selected item. In this article, we will explore how to set the selected item in a dropdown list using ASP.NET Core.

Setting the Selected Item

To set the selected item in a dropdown list, we need to provide the value of the item we want to select. This can be done by setting the “selected” attribute of the corresponding option .

Let's consider an example we have a dropdown list of countries and we want to set the selected item to “ States”. Here's how we can achieve this in ASP.NET Core:


@{
    var countries = new List
    {
        new  { Value = "1", Text = "United States" },
        new SelectListItem { Value = "2", Text = "Canada" },
        new SelectListItem { Value = "3", Text = "United Kingdom" }
    };
    var selectedCountry = "1"; // Set the value of the selected 
}

In the above code, we define a list of SelectListItem the countries. Each object has a Value and Text , which correspond to the value and text of the dropdown options, respectively.

We also define a variable named selectedCountry and set its value to “1”, which represents the value of the selected country.

Rendering the Dropdown List

Now that we have the data and the selected item value, we can render the dropdown list using the HTML helper method DropDownListFor.

Here's an example of how to render the dropdown list in ASP.NET Core:


@Html.DropDownListFor(x => x.SelectedCountry, countries, "Select a country")

In the above code, we use the DropDownListFor method to render the dropdown list. The first parameter is an expression that specifies the property to bind the selected value to. In this case, we use x => x.SelectedCountry to bind the selected value to a property named SelectedCountry.

The parameter is the list of SelectListItem objects representing the dropdown options. In our example, this is the countries list we defined earlier.

The third parameter is an optional string that specifies the text to display as the default option. In our example, we display “Select a country” as the default option.

Conclusion

In this article, we have explored how to set the selected item in a dropdown list using ASP.NET Core. By providing the value of the desired item, we can use the “selected” attribute to set the selected item. We have also seen how to render the dropdown list using the DropDownListFor HTML helper method. With these techniques, you can easily set the selected item in a dropdown list in your ASP.NET Core applications.

Rate this post

Leave a Reply

Your email address will not be published. Required fields are marked *

Table of Contents