What is difference between @Html.Partial() and @Html.RenderPartial() in asp.net MVC C#

Both @Html.Partial() and @Html.RenderPartial() are used to render a partial view in an ASP.NET MVC application, but they differ in how they handle the HTML output.

@Html.Partial() returns a string containing the HTML markup of the partial view, which can then be included as part of the parent view using the Razor syntax. The returned string can be assigned to a variable or passed as a parameter to a method or helper.

Example usage of @Html.Partial():

@Html.Partial("_PartialViewName", model)

@Html.RenderPartial(), on the other hand, directly writes the HTML output of the partial view to the response stream. It does not return any value, so it cannot be assigned to a variable or passed as a parameter to a method or helper.

Example usage of @Html.RenderPartial():

@{ Html.RenderPartial("_PartialViewName", model); }

Notice that we are enclosing Html.RenderPartial() method inside @{ } code block as it doesn't return any value, it just directly writes the HTML output to the response stream.

In general, @Html.RenderPartial() is more efficient than @Html.Partial() because it directly writes the output to the response stream, while @Html.Partial() creates a string that must be returned and then rendered. However, @Html.Partial() is more flexible as it can be assigned to a variable or passed as a parameter to a method or helper.

Another Detail with Code

Suppose we have a ParentView.cshtml view that needs to render a partial view named ChildView.cshtml. The ChildView.cshtml will display some basic information about a product.

Here's how we can use @Html.Partial() to render the ChildView.cshtml as part of the ParentView.cshtml:

ParentView.cshtml File

<div>

    <h2>Parent View</h2>

    @Html.Partial("_ChildView", Model.Product)

</div>

In the example above, the @Html.Partial() method is used to render the _ChildView.cshtml partial view and pass in the Product model as the parameter.

Here's how we can use @Html.RenderPartial() to render the ChildView.cshtml as part of the ParentView.cshtml:

 ParentView.cshtml File

<div>

    <h2>Parent View</h2>

    @{ Html.RenderPartial("_ChildView", Model.Product); }

</div>

In the example above, the @Html.RenderPartial() method is used to render the _ChildView.cshtml partial view and pass in the Product model as the parameter.

Notice that we are enclosing Html.RenderPartial() method inside @{ } code block as it doesn't return any value, it just directly writes the HTML output to the response stream.

Both @Html.Partial() and @Html.RenderPartial() methods can be used to achieve the same result, but @Html.RenderPartial() is more efficient as it directly writes to the response stream without creating an intermediate string, while @Html.Partial() returns a string that needs to be included in the parent view. However, @Html.Partial() is more flexible as it can be assigned to a variable or passed as a parameter to a method or helper.

@Html.Partial() returns a string containing the HTML markup of the partial view, which can then be included as part of the parent view using the Razor syntax. The returned string can be assigned to a variable or passed as a parameter to a method or helper.

Sure, here's an example of how @Html.Partial() can be used to render a partial view and assign the returned HTML markup to a variable:

Suppose we have a partial view named _ProductList.cshtml that displays a list of products. We want to render this partial view inside a ParentView.cshtml view and store the returned HTML markup in a variable named productListHTML. Here's how we can do that:

 ParentView.cshtml File

<div>

    <h2>Parent View</h2>

    @{

        var productListHTML = Html.Partial("_ProductList", Model.Products).ToString();

    }

    <div>

        @Html.Raw(productListHTML)

    </div>

</div>

In the example above, we're using Html.Partial("_ProductList", Model.Products) to render the _ProductList.cshtml partial view and passing in the Products model as the parameter. We're then calling the ToString() method on the returned string to convert it to a string and store it in the productListHTML variable.

Finally, we're using the @Html.Raw() method to output the productListHTML variable as raw HTML. This is necessary because the Html.Partial() method returns an encoded string, so we need to use Html.Raw() to prevent the encoding from being displayed on the page.

By assigning the HTML markup returned by @Html.Partial() to a variable, we can manipulate and use the markup as needed in the parent view or pass it as a parameter to a method or helper.