ASP. NET MVC 5 with EF 6. This tutorial explores how to upload files in an ASP. NET MVC application and how to use Entity Framework to store them in a database. It builds on a series of 1. Contoso University that teach you how to build MVC 5 applications using Entity Framework for data access. The original tutorial series was produced in C# by Tom Dykstra and Rick Anderson ( @Rick. And. MSFT ) of Microsoft. This tutorial is coded in C#. As with the previous tutorials, I have produced a version that uses the Visual Basic language. It is available here. Save the . zip file to a convenient location and then extract the contents. Make sure you have an edition of Visual Studio 2. Unlimited ASP.NET Hosting Plans Starting at $2.95 a month Offering Cutting Edge Windows Hosting Supporting Classic ASP and ASP.NET. Sample Applications. TripXpert Application. Kendo UI ® . Olympic Games Stats. Stock History Dashboard. Web Mail Application. Telerik Northwind Dashboard. Express for Web, Community, Professional, Premium or Ultimate) and double click the . Once the project is opened in your IDE, press Shift+Ctrl+B to build the solution. In this article, we will see how to create a table dynamically in asp.net. We will accept the number of rows and columns in the table from the user. We will then use. A simple example to submit multiple rows in form using Spring 3 MVC. It uses List of beans to submit an array of rows to Spring Controller. Mono has an implementation of ASP.NET 2.0, ASP.NET MVC and ASP.NET AJAX. For deploying applications, we recommend the use of the mod This document describes the release of ASP.NET MVC 3 RTM for Visual Studio 2010. ASP.NET MVC is a framework for developing Web applications that uses the Model-View. Telerik® UI for ASP.NET MVC offers server-side functionality on top of Telerik HTML5/JS library, Kendo UI®. Use them together or separately. This will ensure that all packages are restored from Nuget and may take a while depending on your Internet connection speed. Should I store files in the database or file system? One of the most often asked question in developer forums, the answer to this conundrum is . There are pros and cons to both approaches and this tutorial will not seek to add to the existing debates, but will cover how to approach both options. You will modify the Student CRUD methods and views to store avatar images in the database. Then you will modify the Instructor CRUD methods and views to store images in the field system and their file name in the database. Create File. Type Enumeration for File Types. The application will cater for files that will be used for a variety of purposes, some of which aren't known at the moment. The two types of file that you will start with will be images that serve as an Avatar for a student, and a photo for an instructor. One approach to this might be to add a new property to the User entity for each file. However, it is in the nature of software development that one day, a stakeholder will ask for the application to be modified to cater for personal reports, grades, meeting notes and all sorts of other files. Every time you need to cater for a new file type, you will have to alter the User class and add a new migration. Instead, you will create an enumeration to denote the purpose of each file, and add one property to the user entity to hold a collection of files, regardless of their purpose. Replace the existing code with the following: namespace Contoso. University. Models. If you have already decided to store files in the file system and want to skip this part, feel free to navigate to the second part of the tutorial. Create File Entity. Newer versions of SQL Server offer the File. Stream data type for storing file data. Existing versions of Entity Framework (6. File. Stream data type via Code First. When you store file content in a database, the content itself is stored in binary format. This is represented as an array of bytes in . NET which Entity Framework (currently) maps to the SQL Server varbinary(max) data type. Right click on the Models folder and choose Add New Item. Add a class file, name it File. System. Component. Model. Data. Annotations. Contoso. University. Models. . However, this is not enough to ensure that uploaded file data is accessible on the server. You also used one of the longer overloads of the Html. Begin. Form helper to add an enctype attribute to the form and sets its value to multipart/form- data. This is an essential step to getting file uploading to work. Now add the highlighted code below to the Http. Post Create method in the Students. Controller. Try again, and if the problem persists see your system administrator. The parameter name matches the name attribute's value of the input type=. If the user adds a new student without uploading a file, the upload parameter will equate to null, which is why that condition is checked before any attempt to access the Http. Posted. File. Base. Content. Length property. If you do not perform this check, and then reference the Content. Length property when no file has been uploaded, an exception will be raised. You then check the Content. Length because it is perfectly possible to upload an empty file. If the user does that, the Content. Length property will return 0, and there is no point in storing a file with no data in it. If the upload passes both tests, you create a new File object and assign the relevant properties with values taken from the upload parameter. The binary data is obtained from the Input. Stream property of the uploaded file, and a Binary. Reader object is used to read that into the Content property of the File object. Finally, you add the new File object to the student object. Change the Details method and View. Having stored the image in the database, you need to make some alterations to obtain the image and display it in the Details view. First, you will use the Include method in the LINQ query that fetches the student from the database to bring back releated files. The Include method does not support filtering, so the highlighted line below fetches all files associated with the student regardless of type. Make sure you add this to the web. Views directory - not the one in the root folder.< namespaces>. It results in you not having to use the fully qualified name to reference items in that namespace, such as the File. Type enumeration. If you had not made that change, you would have to do a bit more typing in the view whenever you want to reference types in the Model namespace: @if(Model. Files. Any(f => f. File. Type == Contoso. University. Model. File. Type. Avatar)). If there are, you render the first of these files. The image is rendered using a standard HTML img tag. By convention, the url of the image maps to the Index method of a controller called File, passing in the id of the file as a query string value. Adding the File Controller. Right click on the Controllers folder and choose Add. Controller Choose MVC 5 Controller - Empty from the selection. Name it File. Controller. Replace the templated code with the following: using Contoso. University. DAL. using System. Web. Mvc. namespace Contoso. University. Controllers. Then it returns the image to the browser as a File. Result. Create a new student, making sure that you choose an image file to upload, then navigate to their details to check the result. You have completed the functionality to add an image to be stored in the database to a new student and display it as part of their details. The next section covers how to provide functionality to allow users to edit an existing student's avatar image. Customise the Edit Methods and View. Alter the code in the Http. Get Edit method in the Student. Controller to include the retrieval of files as in the highlighted code below.// GET: Student/Edit/5. Action. Result Edit(int? Try again, and if the problem persists, see your system administrator. As in the Create method, this represents the uploaded file. The highlighted code block checks to see if a file was uploaded, and if one was, that it contains data. These are the same checks as you made in the Create method. If the file contains data, you find any existing files associated with the current student that are Avatar file types. If found, you mark the file for deletion. Then you add the uploaded file as a replacement. Working with the file system. The next section covers how to store uploaded files in the file system instead of in the database. You will create a File. Path entity to represent a single file. Add a new class to the Models folder called File. Path. cs and replace the templated code with the following: namespace Contoso. University. Models. These alterations cover the core concepts that you need to understand when saving files to the file system. Add a new folder to the root directory called . This is mapped to the file upload based on the parameter's name matching the name attribute on the input type=file that you added in the Create view, and provides access to the properties of the uploaded file. The added code checks to ensure that the upload is not null and then checks its Content. Length property to ensure that an empty file as not uploaded. If both of those checks succeed, a new File. Path object is created and its File. Name property is assigned the value of the uploaded file's File. Name, which is obtained by the System. IO. Path. Get. File. Name method. Note: Some browsers provide more than just the file name when files are uploaded. Versions of Internet Explorer will provide the full client file path when you use it locally, i. Other browsers may or may not prepend the file name with values such as C: \Fake. Path\. In any event, you cannot rely on a browser providing just the file's name. Equally, you cannot rely on the browser to provide the original path of the uploaded file. Only some versions of Internet Explorer (currently) do this, and even then, only when your client and server are the same machine. The file itself is saved to the images folder using the value extracted from the upload as the file name. Note: it is not always a good idea to use the file's original name when you store uploads in the file system. Two files with the same name cannot exist in the same location so if a new file is uploaded and saved with the same name as an existing one, the original file will be overwritten when the new one is saved. A common resolution to this problem is to rename the file prior to saving it. Typically, a Guid is used as a file name on the basis that it can pretty much guarantee uniqueness. If you need to adopt this strategy, you can replace the existing line that assigns the File. Path object's File. Name property with the following highlighted line of code: var photo = new File. Path. ? The code that you added to the View checks to see if there are any filepath objects matching the File. Type. Photo type, and if there are, the first one is displayed using an img element. The src attribute value is generated by concatenating the location where files are saved with the name that was given to this particular file.
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