When building WinRT applications there will be the need to create IStorageFiles in the local storage area of your application.  In this post I was going to walk through how we can do this step by step.

Step 1: Get the StorageForlder object for your application

var storageFolder = ApplicationData.Current.LocalFolder;

Step 2: Crate the folder you want to put your file into

var userImagesFolder = await CreateFolder(storageFolder, "UserImages" );

// this is the contents of the CreateFolder method

private async Task<StorageFolder> CreateFolder(StorageFolder storageFolder, string folderName)
{
    StorageFolder folder = null;

    // we do the try w/ empty catch because the GetFolderAsync will throw if not found and we cannot do await inside a catch block
    try
    {
        folder = await storageFolder.GetFolderAsync(folderName);
    }
    catch { }

    if (folder == null)
    {
        folder = await storageFolder.CreateFolderAsync(folderName);
    }

    return folder;

}

Step 3: Create the file object

var myImage = await userImagesFolder.CreateFileAsync("FileName.png", CreationCollisionOption.ReplaceExisting);

Step 4: Write content to the file object

// buffer is a pointer of a memory stream of an image

await FileIO.WriteBufferAsync(newGuestSilhouetteImage, buffer);

All the code in one block

public async Task CreateLocalFile()
{
	var storageFolder = ApplicationData.Current.LocalFolder;
	var userImagesFolder = await CreateFolder(storageFolder, "UserImages" );
	var myImage = await userImagesFolder.CreateFileAsync("FileName.png", CreationCollisionOption.ReplaceExisting);
	await FileIO.WriteBufferAsync(newGuestSilhouetteImage, buffer);
}

private async Task<StorageFolder> CreateFolder(StorageFolder storageFolder, string folderName)
{
    StorageFolder folder = null;

    // we do the try w/ empty catch because the GetFolderAsync will throw if not found and we cannot do await inside a catch block
    try
    {
        folder = await storageFolder.GetFolderAsync(folderName);
    }
    catch { }

    if (folder == null)
    {
        folder = await storageFolder.CreateFolderAsync(folderName);
    }

    return folder;
}

As you can see creating storage files is not much work and is pretty straight forward.

Till next time,