Cloud Storage

Google Cloud Storage allows world-wide storage and retrieval of any amount of data at any time. It can be used for a range of scenarios including serving website content, storing data for archival and disaster recovery, or distributing large data objects to users via direct download.

Enable APIs

For the purposes of this article, you will have to enable the Google Cloud Storage API and Google Cloud Storage JSON API. Please read the Getting Started for more information on how you can achieve that.

Step 1: Create the WPF Application

Create a standard WPF application and add 3 RadButtons and a RadListBox to it. The first button will list all of the files uploaded in our storage. The second button will upload a file and the third one will delete the selected file in the RadListBox.

Example 1: Defining the view

• XAML

<Grid> 
    <Grid.ColumnDefinitions> 
        <ColumnDefinition Width="250" /> 
        <ColumnDefinition /> 
    </Grid.ColumnDefinitions> 
 
    <telerik:RadListBox x:Name="radListBox" ItemsSource="{Binding FileNames}" SelectedItem="{Binding SelectedItem, Mode=TwoWay}" /> 
 
    <Grid Grid.Column="1"> 
        <Grid.RowDefinitions> 
            <RowDefinition Height="Auto" /> 
            <RowDefinition Height="Auto"/> 
            <RowDefinition Height="Auto"/> 
        </Grid.RowDefinitions> 
 
        <telerik:RadButton Command="{Binding ListItemsCommand}"  Content="List Items"/> 
        <telerik:RadButton Command="{Binding UploadItemCommand}" Content="Upload Item" Grid.Row="1"/> 
        <telerik:RadButton Command="{Binding DeleteItemCommand}" Content="Delete item" Grid.Row="2"/> 
    </Grid> 
</Grid> 

Step 2: Install the NuGet package

Open the NuGet Package Manager and install the Google.Cloud.Storage.V1 package.

Step 3: Define the ViewModel

The next step is to create the ViewModel. It will need an StorageClient object which will be used for uploading, deleting and listing files. We also need to implement all of the commands that the RadButtons are bound to.

Example 2: Defining the ViewModel

• C#
• VB.NET

public class ViewModel 
{ 
    private StorageClient storageClient; 
 
    private const string ProjectId = "myprojectId"; 
    private const string BucketName = ProjectId + "-test-bucket"; 
 
    private object selectedItem; 
    private ObservableCollection<string> fileNames; 
    private IFileDialogService fileDialogService; 
 
    public ViewModel(IFileDialogService fileDialogService) 
    { 
        this.storageClient = StorageClient.Create(); 
        storageClient.CreateBucket(ProjectId, BucketName); 
 
        this.fileNames = new ObservableCollection<string>(); 
        this.ListItemsCommand = new DelegateCommand(OnListItems); 
        this.UploadItemCommand = new DelegateCommand(OnUploadItem); 
        this.DeleteItemCommand = new DelegateCommand(OnDeleteItem); 
        this.fileDialogService = fileDialogService; 
    } 
 
    public object SelectedItem 
    { 
        get { return this.selectedItem; } 
        set { this.selectedItem = value; } 
    } 
 
    public ObservableCollection<string> FileNames 
    { 
        get { return this.fileNames; } 
        set { this.fileNames = value; } 
    } 
 
    private ICommand listItemsCommand; 
 
    public ICommand ListItemsCommand 
    { 
        get { return this.listItemsCommand; } 
        set { this.listItemsCommand = value; } 
    } 
 
    private ICommand deleteItemCommand; 
 
    public ICommand DeleteItemCommand 
    { 
        get { return this.deleteItemCommand; } 
        set { this.deleteItemCommand = value; } 
    } 
 
    private ICommand uploadItemCommand; 
 
    public ICommand UploadItemCommand 
    { 
        get { return this.uploadItemCommand; } 
        set { this.uploadItemCommand = value; } 
    } 
 
    private void OnDeleteItem(object obj) 
    { 
        if (this.SelectedItem == null) 
        { 
            MessageBox.Show("Please select an Item"); 
            return; 
        } 
 
        storageClient.DeleteObject(BucketName, this.SelectedItem.ToString()); 
    } 
 
    private void OnUploadItem(object obj) 
    { 
        var fileName = fileDialogService.OpenFileDialog(); 
 
        Stream fileStream = File.OpenRead(fileName); 
 
        var test = storageClient.UploadObject(BucketName, fileName, null, fileStream); 
    } 
 
    private void OnListItems(object obj) 
    { 
        var items = storageClient.ListObjects(BucketName); 
 
        this.FileNames.Clear(); 
 
        foreach (Google.Apis.Storage.v1.Data.Object item in items) 
        { 
            this.FileNames.Add(item.Name); 
        } 
    } 
} 

Public Class ViewModel 
    Private storageClient As StorageClient 
 
    Private Const ProjectId As String = "myprojectId" 
    Private Const BucketName As String = ProjectId & "-test-bucket" 
 
 
    Private _selectedItem As Object 
    Private _fileNames As ObservableCollection(Of String) 
    Private fileDialogService As IFileDialogService 
 
    Public Sub New(ByVal fileDialogService As IFileDialogService) 
        Me.storageClient = StorageClient.Create() 
        storageClient.CreateBucket(ProjectId, BucketName) 
 
        Me._fileNames = New ObservableCollection(Of String)() 
        Me.ListItemsCommand = New DelegateCommand(AddressOf OnListItems) 
        Me.UploadItemCommand = New DelegateCommand(AddressOf OnUploadItem) 
        Me.DeleteItemCommand = New DelegateCommand(AddressOf OnDeleteItem) 
        Me.fileDialogService = fileDialogService 
    End Sub 
 
    Public Property SelectedItem() As Object 
        Get 
            Return Me._selectedItem 
        End Get 
        Set(ByVal value As Object) 
            Me._selectedItem = value 
        End Set 
    End Property 
 
    Public Property FileNames() As ObservableCollection(Of String) 
        Get 
            Return Me._fileNames 
        End Get 
        Set(ByVal value As ObservableCollection(Of String)) 
            Me._fileNames = value 
        End Set 
    End Property 
 
 
    Private _listItemsCommand As ICommand 
 
    Public Property ListItemsCommand() As ICommand 
        Get 
            Return Me._listItemsCommand 
        End Get 
        Set(ByVal value As ICommand) 
            Me._listItemsCommand = value 
        End Set 
    End Property 
 
 
    Private _deleteItemCommand As ICommand 
 
    Public Property DeleteItemCommand() As ICommand 
        Get 
            Return Me._deleteItemCommand 
        End Get 
        Set(ByVal value As ICommand) 
            Me._deleteItemCommand = value 
        End Set 
    End Property 
 
 
    Private _uploadItemCommand As ICommand 
 
    Public Property UploadItemCommand() As ICommand 
        Get 
            Return Me._uploadItemCommand 
        End Get 
        Set(ByVal value As ICommand) 
            Me._uploadItemCommand = value 
        End Set 
    End Property 
 
    Private Sub OnDeleteItem(ByVal obj As Object) 
        If Me.SelectedItem Is Nothing Then 
            MessageBox.Show("Please select an Item") 
            Return 
        End If 
 
        storageClient.DeleteObject(BucketName, Me.SelectedItem.ToString()) 
    End Sub 
 
    Private Sub OnUploadItem(ByVal obj As Object) 
        Dim fileName = fileDialogService.OpenFileDialog() 
 
        Dim fileStream As Stream = File.OpenRead(fileName) 
 
        Dim test = storageClient.UploadObject(BucketName, fileName, Nothing, fileStream) 
    End Sub 
 
    Private Sub OnListItems(ByVal obj As Object) 
        Dim items = storageClient.ListObjects(BucketName) 
 
        Me.FileNames.Clear() 
 
        For Each item As Google.Apis.Storage.v1.Data.Object In items 
            Me.FileNames.Add(item.Name) 
        Next item 
    End Sub 
End Class 

In order to locate your project id, please read the Locate the project ID help article.

Step 4: Define the OpenFileDialogService

The only thing left is to define the interface through which we are opening the RadOpenFileDialog. We also need to define the implementation of that interface which will simply open a RadOpenFileDialog and return the path of the opened file.

Example 3: Defining the OpenFileDialogService and IFileDialogService

• C#
• VB.NET

public interface IFileDialogService 
{ 
    string OpenFileDialog(); 
} 
 
public class OpenFileDialogService : IFileDialogService 
{ 
    public string OpenFileDialog() 
    { 
        RadOpenFileDialog choosefiledialog = new RadOpenFileDialog(); 
        choosefiledialog.Filter = "All Files (.)|."; 
        choosefiledialog.FilterIndex = 1; 
        choosefiledialog.Multiselect = false; 
        choosefiledialog.ShowDialog(); 
 
        if (choosefiledialog.DialogResult == true) 
        { 
            return choosefiledialog.FileName; 
        } 
 
        return string.Empty; 
    } 
} 

Interface IFileDialogService 
    Function OpenFileDialog() As String 
End Interface 
 
Public Class OpenFileDialogService 
Inherits IFileDialogService 
 
    Public Function OpenFileDialog() As String 
        Dim choosefiledialog As RadOpenFileDialog = New RadOpenFileDialog() 
        choosefiledialog.Filter = "All Files (.)|." 
        choosefiledialog.FilterIndex = 1 
        choosefiledialog.Multiselect = False 
        choosefiledialog.ShowDialog() 
        If choosefiledialog.DialogResult = True Then 
            Return choosefiledialog.FileName 
        End If 
 
        Return String.Empty 
    End Function 
End Class 

All that is left is to set the DataContext to our ViewModel and pass an instance of the OpenFileDialogService.

Example 4: Set the DataContext

• C#
• VB.NET

public MainWindow() 
{ 
    InitializeComponent(); 
 
    this.DataContext = new ViewModel(new OpenFileDialogService()); 
} 

Public Sub New() 
    InitializeComponent() 
 
    Me.DataContext = New ViewModel(New OpenFileDialogService()) 
End Sub 

Figure 1: Example after uploading a file and listing it in the Office2016 theme

See Also