Xamariin.Forms- Working With Files Using DependencyService

In this article you will learn how to Create a file using DependencyService in Xamarin forms. 

Introduction

Xamarin.Forms code runs on multiple platforms - each of which has its own filesystem. This means that reading and writing files is most easily done using the native file APIs on each platform. Alternatively, embedded resources are a simpler solution to distribute data files with an app.

User-writable-storage can be implemented natively and then accessed using the DependencyService .

DependencyService

DependencyService allows apps to call into platform-specific functionality from shared code. This functionality enables Xamarin.Forms apps to do anything that a native app can do.

DependencyService is a dependency resolver. In practice, an interface is defined and DependencyService finds the correct implementation of that interface from the various platform projects.


Xamarin.Forms apps need three components to use DependencyService:

1. Interface – The required functionality is defined by an interface in shared code.
2. Implementation Per Platform – Classes that implement the interface must be added to each platform project.
3. Registration – Each implementing class must be registered with DependencyService via a metadata attribute. Registration enables DependencyService to find the implementing class and supply it in place of the interface at run time.
4. Call to DependencyService – Shared code needs to explicitly call DependencyService to ask for implementations of the interface.

The Following Image Explain DependencyService

Prerequisites

• Visual Studio 2017(Windows or Mac)

The steps given below are required to be followed in order to Create a file using DependencyService in Xamarin.Forms, using Visual Studio.


Setting up a Xamarin.Forms Project


Start by creating a new Xamarin.Forms project. you’ll learn more by going through the steps yourself.

Choose the Xamarin.Forms App Project type under Cross-platform/App in the New Project dialog.

Name your app, select “Use Portable Class Library” for shared code, and target both Android and iOS.

You probably want your project and solution to use the same name as your app. Put it in your preferred folder for projects and click Create.

You now have a basic Xamarin.Forms app. Click the play button to try it out.

Creating Interface

Create a interface in Xamarin.Forms PCL

Go to Solution—>PCL—>Right click—>New—>Empty Class—>IFileReadWrite.cs

Now, Write the following code.


IFileReadWrite.cs

Implementation per Platform


Android Implementation

Go to Solution—>Droid—>Right click—>New—>Empty Class—>FileHelper.cs

Now, Write the following code given below.

FileHelper.cs

iOS Implementation

Go to Solution—>iOS—>Right click—>New—>Empty Class—>FileHelper.cs

Now, Write the following code given below.

FileHelper.cs

Setting up the User Interface.

Go MainPage.Xaml and write following code.

MainPage.Xaml

Call to DependencyService

In this step Call to DependencyService for your PCL.

Click the play button to try it out.

I hope you will understand how to Create a file using use DependencyService.

Summary

This was the process of how to Create a file using DependencyService in Xamarin.Forms.

Thanks For Reading.

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How to Read Text File in Xamarin iOS

In this article, you will learn how to Read Text File in Xamarin iOS, using Xamarin Studio.

Introduction

Xamarin is a platform to develop cross-platform and multi-platform apps (for example, Windows phone, Android, iOS). In Xamarin platform, the code sharing concept is used. In Xamarin Studio, Visual Studio is also available.

Prerequisites

• Xamarin Studio.
• Xcode.

The steps given below are required to be followed in order to Read Text File in Xamarin iOS, using Xamarin Studio.

Step 1

Go To Xamarin Studio.

Click New Solution—> select iOS—>select App--> Choose single View App. Afterwards, click Next.

Step 2

In this step, configure your app. Give the app name (Ex:sample), Organization Identifier. Afterwards, click Next.

Step 3

In this step, give your project name (Ex: Sample) and solution name (Ex: Sample). Give the path of your project. Afterwards, click Create.

Step 4

Subsequently, go to the solution. In the solution, get all the files and sources in your project. Now, select Main.storyboard and double click to open Main.storyboard page.

Step 5

After opening the Main.storyboard, you can design this page, as per your desire.

Step 6

Now, go to the toolbox Window. In the toolbox Window, get all the types of the tools and controls. You need to go to the toolbox Window. Now, scroll down and you will see all the tools and controls. You need to drag and drop the Button.
Next You need to align the Button, using constraints.

Step 7

Now, go to the properties Window. Select the Button and give a name (Ex:btnRead).

Step 8


You need to drag and drop the Label.
Next You need to align the Label, using constraints.

Step 9

Now, go to the properties Window. Select the Label and give a name (Ex:lblDisplay).

Step 10

In this step, go to the ViewController.cs page, add the namespace given below.

ViewController.cs

using System.IO;
using System.Threading;

Step 11

In this step, go to the ViewController.cs page. write the code given below.

ViewController.cs

namespace XamariniOSReadFile
{
 public partial class ViewController : UIViewController
 {
  protected ViewController(IntPtr handle) : base(handle)
  {
   // Note: this .ctor should not contain any initialization logic.
  }

  public override void ViewDidLoad()
  {
   base.ViewDidLoad();

   // Perform any additional setup after loading the view, typically from a nib.
  }

  private int ReadFile()
  {
   int count=0;

   using (StreamReader reader = new StreamReader("/Users/DELPIN/Desktop/xamarin.txt"))
   {
    string filecontent = reader.ReadToEnd();

    count = filecontent.Length;
    Thread.Sleep(5000);

   }
   return count;
  }

  partial void BtnRead_TouchUpInside(UIButton sender)
  {

   int count = ReadFile();
   lblDisplay.Text = count.ToString();  
  }

  public override void DidReceiveMemoryWarning()
  {
   base.DidReceiveMemoryWarning();
   // Release any cached data, images, etc that aren't in use.
  }
 }
}

Step 12

Now, go to Run option , choose Debug and the list of iPhone and iPad simulators, which are available. You can choose any one simulator and run it.

Output

After a few seconds, the app will start running on your iPhone simulator.You will see your app working successfully.

                                      

You can click Read File Button. it will be Read how many words in your file to read Successfully.

Summary

This was the process of how to Read Text File in Xamarin ios , using Xamarin Studio.