All about WP7 Isolated Storage - Read and Save Captured Image

published on: 4/11/2011 | Views: N/A | Tags: IsoStore Images

by WindowsPhoneGeek

This is the 8th article from the "All about WP7 Isolated Storage " series of short articles focused on real practical examples with source code rather than a plain theory. I am going to talk about how to read and save Captured Images into Isolated Storage.

• All about WP7 Isolated Storage - intro to Isolated Storage
• All about WP7 Isolated Storage - Creating Folders and files
• All about WP7 Isolated Storage - Store data in IsolatedStorageSettings
• All about WP7 Isolated Storage - Read and Save Text files
• All about WP7 Isolated Storage - Read and Save XML files using XmlSerializer
• All about WP7 Isolated Storage - Read and Save XML files using XmlWriter
• All about WP7 Isolated Storage - Read and Save Images
• All about WP7 Isolated Storage - Read and Save Captured Image
• All about WP7 Isolated Storage - Read and Save Binary files
• All about WP7 Isolated Storage - File manipulations
• All about WP7 Isolated Storage - Recommendations and Best Practices
• All about WP7 Isolated Storage - open source Databases and Helper libraries

In this post we will use the CameraCaptureTask .For more info about performing different tasks in WP7 take a look at our "Launchers and Choosers How to"  series of articles.

NOTE: Use a real device to test CameraCaptureTask! It is not possible to simulate the full camera capture experience on Emulator!  In order to be able to run CameraCaptureTask on Emulator your display driver needs to be directx10 minimum andWDDM1.1 Compliant. Otherwise you will see a black screen. Here are some screen shots:

To begin with lets first create a sample Windows Phone 7 application project and include the following namespaces in MainPage.xaml.cs (alternatively you can use the code in another page):

using Microsoft.Phone.Tasks;
using System.Windows.Media.Imaging;
using System.IO.IsolatedStorage;
using System.IO;
using Microsoft.Phone;

include the following namespaces in MainPage.xaml.cs (alternatively you can use the code in another page):

Save Captured Image to Isolatedstorage

This example demonstrates how to save a captured image to the Isolatedstorage. At first we use the CameraCaptureTask to capture the desired Image. After that we save the Image as Jpg file to Isolatedstorage using BitmapImage and WritableBitmap:

private void btnSave_Click(object sender, RoutedEventArgs e)
{
    ShowCameraCaptureTask();
}

private void ShowCameraCaptureTask()
{
    CameraCaptureTask photoCameraCapture = new CameraCaptureTask();
    photoCameraCapture = new CameraCaptureTask();
    photoCameraCapture.Completed += new EventHandler<PhotoResult>(photoCameraCapture_Completed);
    photoCameraCapture.Show(); 
}

void photoCameraCapture_Completed(object sender, PhotoResult e)
{
    if (e.TaskResult == TaskResult.OK)
    {
        SaveToIsolatedStorage(e.ChosenPhoto,"image1.jpg");
    } 
}

private void SaveToIsolatedStorage(Stream imageStream, string fileName)
{
    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (myIsolatedStorage.FileExists(fileName))
        {
            myIsolatedStorage.DeleteFile(fileName);
        }

        IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile(fileName);
        BitmapImage bitmap = new BitmapImage();
        bitmap.SetSource(imageStream);

        WriteableBitmap wb = new WriteableBitmap(bitmap);
        wb.SaveJpeg(fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
        fileStream.Close();
    }
}

NOTE: Use a real device to test CameraCaptureTask! It is not possible to simulate the full camera capture task in Emulator!

Read Captured Image from Isolatedstorage

In this example at first open the previously created image1.jpg Image file from the Isolated Storage and read its content. After that the content is visualized in an Image control:

private void ReadFromIsolatedStorage(string fileName)
{
    WriteableBitmap bitmap = new WriteableBitmap(200,200);
    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        using (IsolatedStorageFileStream fileStream = myIsolatedStorage.OpenFile(fileName, FileMode.Open, FileAccess.Read))
        {
            // Decode the JPEG stream.
             bitmap = PictureDecoder.DecodeJpeg(fileStream);
        }
    }
    this.img.Source = bitmap;
}

private void btnLoad_Click(object sender, RoutedEventArgs e)
{
    this.ReadFromIsolatedStorage("image1.jpg");
}

NOTE: When open an existing file from the Isolated Storage we use  FileMode.Open, when we want to read to a file we use FileAccess.Read! You can find a list of all FileAccess possibilities here.

NOTE: "img" is an ImageControl placed inside MainPage.xaml: <Image x:Name="img"/>

In this article I talked about reading and saving Images into Isolated Storage. Here is the full source code:

Stay tuned with the rest of the posts. I hope that the article was helpful.

You can also follow us on Twitter @winphonegeek

Comments

Add comment to 'All about WP7 Isolated Storage - Read and Save Captured Image'

Title Your Name

Comment