Introduction
Xamarin.Forms code runs on multiple platforms - each of which has its own file system. We can share most of the Xamarin form code to multiple platforms. All the mobile platforms have their own file system like read, write, delete files. We don’t have any direct API for sharing File System, using Xamarin form.
Xamarin recommends third -party component called PCLStorage. We can share our file storage library with all the platforms. There is no need to write it separately.
PCLStorage
PCL Storage provides a consistent, portable set of local file IO APIs for .NET, Windows Phone, Windows Store, Xamarin.iOS, Xamarin.Android and Silverlight. This makes it easier to create cross-platform .NET libraries and apps.
Here is a sample, which shows how you can use PCL Storage to create a folder and write to a text file in the folder.
I have created a sample application and published the Basic Storage Recipes sample, using Xamarin Form. Download the sample to see working examples of the programming tasks.
Here, the list of tasks is demonstrated in the Basic Storage Recipes sample.
In addition to showing you how to work with the files and PCL Storage sample, it also demonstrates the following tasks.
- Read File
- Write file
- Create Folder
- Check folder and file exists
- Save Image
- Read Image
- Delete File
- Replace file
Create New Xamarin.Form Application
Xamarin.Forms is a cross-platform UI toolkit, which allows the user to efficiently create a native user interface layout. The code can be shared with all the devices (IOS, Android, Windows Phone, and Win store app). Just refer to my previous article to create a new Xamarin Form Application
here.
Add PCLStorage Nuget Package
Add the PCLStorage Nuget package to all the projects. Right-click on Project Solution. Click “Manage NuGet package for Solution “. Search and select “PCLStorage”. Select all the Projects. Click Install.
More about
PCLStorage.
Start creating the code from a portable library, as shown below.
Cross-platform Local Folder
In Xamarin.Form, the PCLStorage API will help us to retrieve all the platforms' local folder names and paths, using the code given below. There is no need to write any platform-specific code to access the local folder.
- Using PCLStorage;
-
- IFolder folder = FileSystem.Current.LocalStorage;
Creating new folders
To create a new subfolder in the local folder, call the CreateFolderAsync method.
- String folderName =”csharp” ;
- IFolder folder = FileSystem.Current.LocalStorage;
- folder = await folder.CreateFolderAsync(folderName, CreationCollisionOption.ReplaceExisting);
Create New file
To create a new file in the local folder, call the CreateFileAsync method.
- String filename=”username.txt”;
- IFolder folder = FileSystem.Current.LocalStorage;
- IFile file = await folder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
Check Folder Already Exists
We can check for an existing folder in a particular folder, as shown below.
- public async static Task<bool> IsFolderExistAsync(this string folderName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- ExistenceCheckResult folderexist = await folder.CheckExistsAsync(folderName);
-
- if (folderexist == ExistenceCheckResult.FolderExists)
- {
- return true;
-
- }
- return false;
- }
Check File Already Exists
We can check for an existing file in a particular folder, as shown below.
- public async static Task<bool> IsFileExistAsync(this string fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- ExistenceCheckResult folderexist = await folder.CheckExistsAsync(fileName);
-
- if (folderexist == ExistenceCheckResult.FileExists)
- {
- return true;
-
- }
- return false;
- }
Delete File
We can use the DeleteAsync method to delete the file.
- public async static Task<bool> DeleteFile(this string fileName, IFolder rootFolder = null)
- {
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- bool exist = await fileName.IsFileExistAsync(folder);
- if (exist == true)
- {
- IFile file = await folder.GetFileAsync(fileName);
- await file.DeleteAsync();
- return true;
- }
- return false;
- }
Write File
If you want to write any extension file document, just use the WriteAllTextAsync method for write.
- public async static Task<bool> WriteTextAllAsync(this string filename, string content = "", IFolder rootFolder = null)
- {
- IFile file = await filename.CreateFile(rootFolder);
- await file.WriteAllTextAsync(content);
- return true;
- }
Read File
If you want to read any extension file document, just use the ReadAllTextAsync method for write.
- public async static Task<string> ReadAllTextAsync(this string fileName, IFolder rootFolder = null)
- {
- string content = "";
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- bool exist = await fileName.IsFileExistAsync(folder);
- if (exist == true)
- {
- IFile file = await folder.GetFileAsync(fileName);
- content = await file.ReadAllTextAsync();
- }
- return content;
- }
Save Image
We can save the image, using PCLStorage, as shown below.
- public async static Task SaveImage(this byte[] image,String fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
-
-
- IFile file = await folder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
-
-
- using (System.IO.Stream stream = await file.OpenAsync(FileAccess.ReadAndWrite))
- {
- stream.Write(image, 0, image.Length);
- }
- }
Get Image
We can load an image, using PCLStorage, as shown below.
- public async static Task<byte[]> LoadImage(this byte[] image, String fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
-
-
- IFile file = await folder.GetFileAsync(fileName);
-
- using (System.IO.Stream stream = await file.OpenAsync(FileAccess.ReadAndWrite))
- {
- long length = stream.Length;
- byte[] streamBuffer = new byte[length];
- stream.Read(streamBuffer, 0, (int)length);
- return streamBuffer;
- }
-
- }
PCL Helper Class
I have created a very simple PCLHelper class. You can refer to it and reuse it in your project.
- using PCLStorage;
- using System;
- using System.Threading.Tasks;
-
- namespace DevEnvExe_LocalStorage
- {
- public static class PCLHelper
- {
-
- public async static Task<bool> IsFileExistAsync(this string fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- ExistenceCheckResult folderexist = await folder.CheckExistsAsync(fileName);
-
- if (folderexist == ExistenceCheckResult.FileExists)
- {
- return true;
-
- }
- return false;
- }
-
- public async static Task<bool> IsFolderExistAsync(this string folderName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- ExistenceCheckResult folderexist = await folder.CheckExistsAsync(folderName);
-
- if (folderexist == ExistenceCheckResult.FolderExists)
- {
- return true;
-
- }
- return false;
- }
-
- public async static Task<IFolder> CreateFolder(this string folderName, IFolder rootFolder = null)
- {
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- folder = await folder.CreateFolderAsync(folderName, CreationCollisionOption.ReplaceExisting);
- return folder;
- }
-
- public async static Task<IFile> CreateFile(this string filename, IFolder rootFolder = null)
- {
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- IFile file = await folder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
- return file;
- }
- public async static Task<bool> WriteTextAllAsync(this string filename, string content = "", IFolder rootFolder = null)
- {
- IFile file = await filename.CreateFile(rootFolder);
- await file.WriteAllTextAsync(content);
- return true;
- }
-
- public async static Task<string> ReadAllTextAsync(this string fileName, IFolder rootFolder = null)
- {
- string content = "";
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- bool exist = await fileName.IsFileExistAsync(folder);
- if (exist == true)
- {
- IFile file = await folder.GetFileAsync(fileName);
- content = await file.ReadAllTextAsync();
- }
- return content;
- }
- public async static Task<bool> DeleteFile(this string fileName, IFolder rootFolder = null)
- {
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
- bool exist = await fileName.IsFileExistAsync(folder);
- if (exist == true)
- {
- IFile file = await folder.GetFileAsync(fileName);
- await file.DeleteAsync();
- return true;
- }
- return false;
- }
- public async static Task SaveImage(this byte[] image,String fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
-
-
- IFile file = await folder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
-
-
- using (System.IO.Stream stream = await file.OpenAsync(FileAccess.ReadAndWrite))
- {
- stream.Write(image, 0, image.Length);
- }
- }
-
- public async static Task<byte[]> LoadImage(this byte[] image, String fileName, IFolder rootFolder = null)
- {
-
- IFolder folder = rootFolder ?? FileSystem.Current.LocalStorage;
-
-
- IFile file = await folder.GetFileAsync(fileName);
-
- using (System.IO.Stream stream = await file.OpenAsync(FileAccess.ReadAndWrite))
- {
- long length = stream.Length;
- byte[] streamBuffer = new byte[length];
- stream.Read(streamBuffer, 0, (int)length);
- return streamBuffer;
- }
-
- }
- }
- }
I believe this will be helpful for all Xamarin developers. If you have any questions, please post them in the comment box.
Add PCLStorage Nuget Package
Add the PCLStorage Nuget package to all the projects. Right-click on Project Solution. Click “Manage NuGet package for Solution “. Search and select “PCLStorage”. Select all the Projects. Click Install.
More about PCLStorage.
Start creating the code from a portable library, as shown below.
Cross-platform Local Folder
In Xamarin.Form, the PCLStorage API will help us to retrieve all the platforms' local folder names and paths, using the code given below. There is no need to write any platform-specific code to access the local folder.
Christian PfalzgrafPosted Jul 27, 2021, 3:27 PM
PCLStorage are not supported anymore, just use System.IO that work on every platforms.
Dave ArndtPosted Oct 29, 2020, 9:13 AM
Can one use PCLStorage to write to public folders, i.e., the Download folder? Example?
arulraj ganesanPosted Sep 19, 2020, 11:31 PM
listvew using export CSV,excel,pdf download from android local directory
arulraj ganesanPosted Sep 19, 2020, 8:22 PM
no man I need to store the CSV file in .. mobile device directory..give any sample please
arulraj ganesanPosted Sep 19, 2020, 8:17 PM
no man I need to store the data in mobile device directory..
arulraj ganesanPosted Sep 19, 2020, 2:25 PM
ji we need export CSV in android local store
arulraj ganesanPosted Sep 19, 2020, 5:43 AM
Ji it possible to write csv file in xmarain android native app..u have any sample code
arulraj ganesanPosted Sep 18, 2020, 4:32 AM
Hi i need how to export csv file in xmarain ..any sample code?
Mark ZablockiPosted Feb 20, 2020, 10:42 AM
Hi I am new to the programing community and I am trying to teach myself C# .NET and cross platform programming, I have implemented the simple class the you wrote and I have referenced it in a small project that I am using to test with called FileBrowserTest, The next stage for me is to call one of those specific functions and test them on my emulator...Using VS2019 and nexus_6_9.0_-_api28, is it possible for you to help me and just give a quick example on how to call for example one of those functions? Maybe an example on how to call a function that opens a folder dialog? Any help would be greatly appreciated.
Jaime StuardoPosted Jul 8, 2019, 7:09 PM
Hello... can you help me? I am using PCLStorage. When getting the local folder, it retrieves /data/data/com.company.MyApp/files, however, that path does not exist anywhere. I used CreateFolderAsync to create a folder, and it is created because I check folder existence using CheckExistsAsync. But I cannot find it !! where is it? I need to find it because I have to save a file in there using file explorer. The more similar folder I've found is \Internal storage\Android\data\com.company.MyApp\files, but the created folder does not appear there. Is this magical or something?
Liêm NguyễnPosted Mar 24, 2019, 1:58 AM
How to COPY exist file to that folder?
Liêm NguyễnPosted Mar 24, 2019, 1:52 AM
Can create a JSON file??
ram aPosted Nov 19, 2018, 11:46 AM
PCL Storage is getting stucked on Folder check??
Ubaid RehmanPosted Nov 8, 2018, 5:55 AM
Can I save sound files by following the same steps as images? I want to save (.wav) recording into my local storage. Please Advise
Samuel ArthursPosted Sep 12, 2018, 9:57 PM
Helped me a lot ! Thank you sir ! :) Sir, I need one help how can i get that permission from my app when its not enabled ? Please help me or provide me some reference to it.
JCA TechPosted Aug 15, 2018, 4:47 AM
There is no no PCLStorage in my Nuget i search it but the PCLStorage is not available in my Nuget does any body knows the problem or help me to get the PCLStorage setup
Srusti ThakkarPosted Jan 24, 2018, 2:29 AM
I want to list down only media files from internal as well as external storage. How is it possible with this?
markand bhattPosted Dec 26, 2017, 1:22 AM
I am suffering with one condition , I want to save data in Local and then if there is internet connection then it will sync to server , I want Queing like system , is it possible with PCL storage , i am using Web API for my BackEnd Process coz my backend is as Microsoft sql server , Kindly guode for same \
markand bhattPosted Dec 26, 2017, 1:20 AM
Thank you sir Very good Blog,
Giovanni LopezPosted Nov 4, 2017, 5:44 AM
Hi Suthahar, I have the same issue of Himanshu Lanjewar. I want to read a sample.txt file from Documents folder in iOS. This file must be imported from iTunes. How Can I refer to Documents folder from your PCL storage? thank you for your support.
Himanshu LanjewarPosted Oct 10, 2017, 9:30 AM
Hey I am trying to create IFolder during folder creation. IFolder?folder?=?rootFolder????FileSystem.Current.LocalStorage; But it always gives exception
Parshwa kapadiaPosted Sep 14, 2017, 1:36 AM
Hey, When I'm trying to store uploading image path in local storage and when I'm trying to get the that file each and every time I get different path. Any idea ? Thanks.
Lionel MennigPosted Jul 24, 2017, 10:33 AM
Hey, I'm saving images as you do from bytes arrays but I can't open them afterwards under operating system because there is no file format. I've been trying to rename it with ".jpg", ".png", ".bmp" but no program could open/show it. Any tip ? Thanks.
Ajay SinghPosted Jan 25, 2017, 4:20 AM
Very mice.. It really helped me.
Fabio Silva LimaPosted Dec 12, 2016, 5:39 AM
I forgot to say something. what you think if you change name from Xamarin.Form to Xamarin.Forms "plural".?
Fabio Silva LimaPosted Dec 12, 2016, 5:38 AM
Very good Mr! Congratulations.
Thiruppathi RPosted Dec 12, 2016, 12:24 AM
thank you for your information.