Xamariin.Forms- Working With Directory Using DependencyService

In this article you will learn how to Create a Directory , Rename Directory and Delete 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:

• Interface – The required functionality is defined by an interface in shared code.
• Implementation Per Platform – Classes that implement the interface must be added to each platform project.
• 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.
• Call to DependencyService – Shared code needs to explicitly call DependencyService to ask for implementations of the interface.

Following Topic Covered.

1.Create Directory 
2.Rename Directory 
3.Delete Directory

Related Post: Xamarin.Forms - Working With Files Using DependencyService

Prerequisites

• Visual Studio 2017(Windows or Mac)

The steps given below are required to be followed in order to Create a Directory , Rename Directory and Delete 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—>IDirectory.cs

Now, Write the following code.

IDirectory.cs

	using System;
	namespace XamarinForms_Files
	{
	public interface IDirectory {
	string CreateDirectory(string directoryName);
	void RemoveDirectory();
	string RenameDirectory(string oldDirectoryName, string newDirectoryName);
	}
	}

view raw IDirectory.cs hosted with ❤ by GitHub

Implementation per Platform

iOS Implementation

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

Now, Write the following code given below.

DirectoryHelper.cs

	using System;
	using System.IO;
	using Xamarin.Forms;
	using XamarinForms_Files.iOS;
	[assembly: Dependency(typeof(DirectoryHelper))]
	namespace XamarinForms_Files.iOS {
	public class DirectoryHelper: IDirectory {
	public string documentBasePath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
	public string CreateDirectory(string directoryName) {
	var directoryPath = Path.Combine(documentBasePath, directoryName);
	if (!Directory.Exists(directoryPath)) {
	Directory.CreateDirectory(directoryPath);
	}
	return directoryPath;
	}
	public void RemoveDirectory() {
	DirectoryInfo directory = new DirectoryInfo(documentBasePath);
	foreach(DirectoryInfo dir in directory.GetDirectories()) {
	dir.Delete(true);
	}
	}
	public string RenameDirectory(string oldDirectoryName, string newDirectoryName) {
	var olddirectoryPath = Path.Combine(documentBasePath, oldDirectoryName);
	var newdirectoryPath = Path.Combine(documentBasePath, newDirectoryName);
	if (Directory.Exists(olddirectoryPath)) {
	Directory.Move(olddirectoryPath, newdirectoryPath);
	}
	return newdirectoryPath;
	}
	}
	}

view raw DirectoryHelper.cs hosted with ❤ by GitHub

Android Implementation

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

Now, Write the following code given below.

DirectoryHelper.cs

	using System;
	using System.IO;
	using Xamarin.Forms;
	using XamarinForms_Files.Droid;
	[assembly: Dependency(typeof(DirectoryHelper))]
	namespace XamarinForms_Files.Droid {
	public class DirectoryHelper: IDirectory {
	public string documentBasePath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
	public string CreateDirectory(string directoryName) {
	var directoryPath = Path.Combine(documentBasePath, directoryName);
	if (!Directory.Exists(directoryPath)) {
	Directory.CreateDirectory(directoryPath);
	}
	return directoryPath;
	}
	public void RemoveDirectory() {
	DirectoryInfo directory = new DirectoryInfo(documentBasePath);
	foreach(DirectoryInfo dir in directory.GetDirectories()) {
	dir.Delete(true);
	}
	}
	public string RenameDirectory(string oldDirectoryName, string newDirectoryName) {
	var olddirectoryPath = Path.Combine(documentBasePath, oldDirectoryName);
	var newdirectoryPath = Path.Combine(documentBasePath, newDirectoryName);
	if (!Directory.Exists(olddirectoryPath)) {
	Directory.Move(olddirectoryPath, newdirectoryPath);
	}
	return newdirectoryPath;
	}
	}
	}

view raw DirectoryHelper.cs hosted with ❤ by GitHub

Setting up the User Interface. 

Go MainPage.Xaml and write following code.

MainPage.Xaml

	<?xml version="1.0" encoding="utf-8"?>
	<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:XamarinForms_Files" x:Class="XamarinForms_Files.XamarinForms_FilesPage">
	<StackLayout VerticalOptions="CenterAndExpand" HorizontalOptions="Center">
	<Entry x:Name="txtDirectory" Placeholder="Enter Directory Name..."></Entry>
	<Button x:Name="btnCreate" Text="Create"></Button>
	<Entry x:Name="txtDirectoryRename" Placeholder="Enter New Directory Name..."></Entry>
	<Button x:Name="btnRename" Text="Rename"></Button>
	<Button x:Name="btnRemove" Text="Remove"></Button> </StackLayout>
	</ContentPage>

view raw MainPage.xaml hosted with ❤ by GitHub

Call to DependencyService

In this step Call to DependencyService for your PCL.

	using Xamarin.Forms;
	namespace XamarinForms_Files {
	public partial class XamarinForms_FilesPage: ContentPage {
	string oldDirectoryName;
	public XamarinForms_FilesPage() {
	InitializeComponent();
	btnCreate.Clicked += (sender, e) => {
	oldDirectoryName = txtDirectory.Text;
	//Create a Directory Using DependencyService
	DependencyService.Get < IDirectory > ().CreateDirectory(txtDirectory.Text);
	};
	btnRename.Clicked += (sender, e) => {
	//Rename Directory Using DependencyService
	DependencyService.Get < IDirectory > ().RenameDirectory(oldDirectoryName, txtDirectoryRename.Text);
	};
	btnRemove.Clicked += (sender, e) => {
	//Remove Directory Using DependencyService
	DependencyService.Get < IDirectory > ().RemoveDirectory();
	};
	}
	}
	}

view raw MainPage.xaml.cs hosted with ❤ by GitHub

Click the play button to try it out.

I hope you will understand how to Create Directory , Rename Directory and Delete a file using use DependencyService.


Summary

This was the process of how to reate Directory , Rename Directory and Delete using DependencyService in Xamarin.Forms.

Thanks For Reading.

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