Uploading and Previewing Files

You can use Uploader for Silverlight in combination with PDF for Silverlight to create and upload PDF files to the server. In this topic we use the C1Uploader class along with C1Pdf to create PDF files uploaded to a stream so a user can preview files to print. Note that for simplicity the project uses the C1UploaderHelper.cs code file included with the Uploader for Silverlight samples.

Complete the following steps to create the project:

In Visual Studio 2008, select File | New | Project.
In the New Project dialog box, select a language in the left pane, and in the templates list select Silverlight Application. Enter a Name for your project and click OK. The New Silverlight Application dialog box appears.
Click OK to accept default settings, close the New Silverlight Application dialog box, and create your project. The MainPage.xaml file opens.
Right-click the project in the Solution Explorer window and select Add Reference.
In the Add Reference dialog box, locate and select the C1.Silverlight.Pdf.dll and C1.Silverlight.Uploader.dll assemblies and click OK to add references to your project.

in the MainPage.xaml file, between the <Grid> and </Grid> tags, add the following XAML markup:

XAML	Copy Code
<StackPanel Width="300" HorizontalAlignment="Center" VerticalAlignment="Center"> <TextBlock Text="Enter text here:" Margin="10"/> <TextBox Name="tb" Margin="10" Height="100" TextWrapping="Wrap"/> <Button Content="Print and Open PDF" Margin="10" Click="Button_Click" /> </StackPanel>

XAML

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<StackPanel Width="300" HorizontalAlignment="Center" VerticalAlignment="Center"> 
    <TextBlock Text="Enter text here:" Margin="10"/> 
    <TextBox Name="tb" Margin="10" Height="100" TextWrapping="Wrap"/> 
    <Button Content="Print and Open PDF" Margin="10" Click="Button_Click" /> 
</StackPanel>

This markup creates a text box to enter text to include in the PDF and a button for users to click to turn the text into a PDF and upload the file to the server.

In the Solution Explorer, right-click the MyProjectWeb application where "MyProject" is the name of your project application. Select New Folder and name the folder "temp." This folder contains the PDF file.

Complete the following steps to code the button click and upload methods:

In the Solution Explorer, right-click MainPage.xaml file and select View Code to switch to Code view.

In Code view, add the following import statements to the top of the page if they are not included:

Visual Basic	Copy Code
Imports System.IO Imports C1.Silverlight.Pdf Imports C1.Silverlight.Uploader

C#	Copy Code
using System.IO; using C1.Silverlight.Pdf; using C1.Silverlight.Uploader;

Add the following code to the MainPage class:

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Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs) ' Create PDF Dim doc As New C1PdfDocument() Dim st As String = Nothing st = tb.Text doc.DrawString(st, New Font("Arial", 14), Colors.Black, New Rect(0, 0, 500, 100)) ' Generate stream Dim stream As Stream stream = New MemoryStream() doc.Save(stream) ' Upload stream Dim uploader = CreateUploader() uploader.AddFile("test.pdf", stream) uploader.BeginUploadFiles() AddHandler uploader.UploadCompleted, AddressOf uploader_UploadCompleted End Sub Private Sub uploader_UploadCompleted(ByVal sender As Object, ByVal e As UploadCompletedEventArgs) ' Navigate to PDF If e.[Error] Is Nothing Then Dim url = New Uri(DirectCast(e.Response, String())(0)) System.Windows.Browser.HtmlPage.Window.Navigate(url) End If End Sub Private Function CreateUploader() As C1Uploader Dim mpUploader As New C1UploaderPost(FilesPerRequest.AllFilesInOneRequest) mpUploader.Settings.Address = C1.Silverlight.Extensions.GetAbsoluteUri("Handler.ashx") Return mpUploader End Function

Visual Basic

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Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs) 
    ' Create PDF 
    Dim doc As New C1PdfDocument() 
    Dim st As String = Nothing 

    st = tb.Text 

    doc.DrawString(st, New Font("Arial", 14), Colors.Black, New Rect(0, 0, 500, 100)) 

    ' Generate stream 
    Dim stream As Stream 
    stream = New MemoryStream() 
    doc.Save(stream) 

    ' Upload stream 
    Dim uploader = CreateUploader() 
    uploader.AddFile("test.pdf", stream) 
    uploader.BeginUploadFiles() 
    AddHandler uploader.UploadCompleted, AddressOf uploader_UploadCompleted 
End Sub 

Private Sub uploader_UploadCompleted(ByVal sender As Object, ByVal e As UploadCompletedEventArgs) 
    ' Navigate to PDF 
    If e.[Error] Is Nothing Then 
        Dim url = New Uri(DirectCast(e.Response, String())(0)) 
        System.Windows.Browser.HtmlPage.Window.Navigate(url) 
    End If 
End Sub 

Private Function CreateUploader() As C1Uploader 
    Dim mpUploader As New C1UploaderPost(FilesPerRequest.AllFilesInOneRequest) 
    mpUploader.Settings.Address = C1.Silverlight.Extensions.GetAbsoluteUri("Handler.ashx") 
    Return mpUploader 
End Function

C#	Copy Code
private void Button_Click(object sender, RoutedEventArgs e) { // Create PDF C1PdfDocument doc = new C1PdfDocument(); doc.DrawString(tb.Text, new Font("Arial", 12), Colors.Black, new Rect(0, 0, 500, 100)); // Generate stream Stream stream; stream = new MemoryStream(); doc.Save(stream); // Upload stream var uploader = CreateUploader(); uploader.AddFile("test.pdf", stream); uploader.BeginUploadFiles(); uploader.UploadCompleted += new EventHandler<UploadCompletedEventArgs>(uploader_UploadCompleted); } void uploader_UploadCompleted(object sender, UploadCompletedEventArgs e) { // Navigate to PDF if (e.Error == null) { var url = new Uri(((string[])e.Response)[0]); System.Windows.Browser.HtmlPage.Window.Navigate(url); } } private C1Uploader CreateUploader() { C1UploaderPost mpUploader = new C1UploaderPost(FilesPerRequest.AllFilesInOneRequest); mpUploader.Settings.Address = C1.Silverlight.Extensions.GetAbsoluteUri("Handler.ashx"); return mpUploader; }

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private void Button_Click(object sender, RoutedEventArgs e) 
{ 
    // Create PDF 
    C1PdfDocument doc = new C1PdfDocument(); 
    doc.DrawString(tb.Text, new Font("Arial", 12), Colors.Black, new Rect(0, 0, 500, 100)); 

    // Generate stream 
    Stream stream; 
    stream = new MemoryStream(); 
    doc.Save(stream); 

    // Upload stream 
    var uploader = CreateUploader(); 
    uploader.AddFile("test.pdf", stream); 
    uploader.BeginUploadFiles(); 
    uploader.UploadCompleted += new EventHandler<UploadCompletedEventArgs>(uploader_UploadCompleted); 
} 

void uploader_UploadCompleted(object sender, UploadCompletedEventArgs e) 
{ 
    // Navigate to PDF 
    if (e.Error == null) 
    { 
        var url = new Uri(((string[])e.Response)[0]); 
        System.Windows.Browser.HtmlPage.Window.Navigate(url); 
    } 
} 

private C1Uploader CreateUploader() 
{ 
    C1UploaderPost mpUploader = new C1UploaderPost(FilesPerRequest.AllFilesInOneRequest); 
    mpUploader.Settings.Address = C1.Silverlight.Extensions.GetAbsoluteUri("Handler.ashx"); 
    return mpUploader; 
}

Complete the following steps to process requests:

In the Visual Studio Solution Explorer, right-click the MyProjectWeb solution where "MyProject" is the name of your project. Select the Add | Existing Item option.
In the Add Existing Item dialog box, navigate to the ControlExplorerWeb folder where samples are installed, select the C1UploaderHelper.cs file, and click the Add button.
By default the ControlExplorerWeb folder is located in the Documents or My Documents folder at ComponentOne Samples\Studio for Silverlight\ControlExplorer\ControlExplorerWeb.
In the Visual Studio Solution Explorer, right-click the MyProjectWeb solution where "MyProject" is the name of your project. Select the Add | New Item option.
In the Add New Item dialog box, select the Generic Handler template and name the new class "Handler.ashx."
Click Add to add the file to your project and close the Add New Item dialog box.

Open the Handler.ashx code file and add the following import statement (where "MyProject" is the name of your project application in the Solution Explorer) to the top of the page if it is not included:

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Imports System.Web Imports System.Web.Services Imports MyProject

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using System.Web; using System.Web.Services; using MyProject;

Replace the default implementation of the ProcessRequest method with the following code:

Visual Basic	Copy Code
Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest Try ' Get custom parameters Dim parameters As String = context.Request.Params("parameters") For i As Integer = 0 To context.Request.Files.Count - 1 ' Get the uploaded file, and calculates the full path to save it in the server Dim file As HttpPostedFile = context.Request.Files(i) Dim serverFileName As String = C1UploaderHelper.GetServerPath(context.Server, file.FileName) If C1UploaderHelper.ProcessPart(context, file.InputStream, serverFileName, 1, 1) Then ' Add the URL of the uploaded file to the response Dim url As String = C1UploaderHelper.GetUploadedFileUrl(context, "Handler.ashx",file.FileName) context.Response.Write((If(i > 0, "\|", String.Empty)) + url) Else C1UploaderHelper.WriteError(context, C1UploaderHelper.ERROR_MESSAGE) Exit For End If Next Catch exc As Exception C1UploaderHelper.WriteError(context, exc.Message) context.Response.[End]() End Try End Sub

Visual Basic

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Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest 
    Try 
        ' Get custom parameters 
        Dim parameters As String = context.Request.Params("parameters") 

        For i As Integer = 0 To context.Request.Files.Count - 1 
        ' Get the uploaded file, and calculates the full path to save it in the server 
        Dim file As HttpPostedFile = context.Request.Files(i) 
        Dim serverFileName As String = C1UploaderHelper.GetServerPath(context.Server, file.FileName) 

        If C1UploaderHelper.ProcessPart(context, file.InputStream, serverFileName, 1, 1) Then 
            ' Add the URL of the uploaded file to the response 
            Dim url As String = C1UploaderHelper.GetUploadedFileUrl(context, "Handler.ashx",file.FileName) 
            context.Response.Write((If(i > 0, "|", String.Empty)) + url) 
        Else 
            C1UploaderHelper.WriteError(context, C1UploaderHelper.ERROR_MESSAGE) 
            Exit For 
        End If 
        Next 
        Catch exc As Exception 
        C1UploaderHelper.WriteError(context, exc.Message) 
        context.Response.[End]() 
    End Try 
End Sub

C#	Copy Code
public void ProcessRequest(HttpContext context) { try { // Get custom parameters string parameters = context.Request.Params["parameters"]; for (int i = 0; i < context.Request.Files.Count; i++) { // Get the uploaded file, and calculates the full path to save it in the server HttpPostedFile file = context.Request.Files[i]; string serverFileName = C1UploaderHelper.GetServerPath(context.Server,file.FileName); if (File.Exists(file.FileName)) File.Delete(file.FileName); if (C1UploaderHelper.ProcessPart(context, file.InputStream, serverFileName, 1, 1)) { // Add the URL of the uploaded file to the response string url = C1UploaderHelper.GetUploadedFileUrl(context,"Handler.ashx", file.FileName); context.Response.Write((i > 0 ? "\|" : string.Empty) + url); } else { C1UploaderHelper.WriteError(context, C1UploaderHelper.ERROR_MESSAGE); break; } } } catch (Exception exc) { C1UploaderHelper.WriteError(context, exc.Message); context.Response.End(); } }

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public void ProcessRequest(HttpContext context) 
{ 
    try 
    { 
        // Get custom parameters 
        string parameters = context.Request.Params["parameters"]; 
        for (int i = 0; i < context.Request.Files.Count; i++) 
        { 
            // Get the uploaded file, and calculates the full path to save it in the server 
            HttpPostedFile file = context.Request.Files[i]; 
            string serverFileName = C1UploaderHelper.GetServerPath(context.Server,file.FileName); 
            if (File.Exists(file.FileName)) 
                File.Delete(file.FileName); 
            if (C1UploaderHelper.ProcessPart(context, file.InputStream, serverFileName, 1, 1)) 
            { 
                // Add the URL of the uploaded file to the response 
                string url = C1UploaderHelper.GetUploadedFileUrl(context,"Handler.ashx", file.FileName); 
                context.Response.Write((i > 0 ? "|" : string.Empty) + url); 
            } 
            else 
            { 
                C1UploaderHelper.WriteError(context, C1UploaderHelper.ERROR_MESSAGE); 
                break; 
            } 
        } 
    } 
    catch (Exception exc) 
    { 
        C1UploaderHelper.WriteError(context, exc.Message); 
        context.Response.End(); 
    } 
}

What You've Accomplished

You've successfully created a Silverlight application that uploads and previews text in a PDF file. To observe how the application works, complete the following steps:

To run the application, select Debug | Start Debugging.
Enter text in the text box, for example "Hello World!"
Click the Print and Open PDF button.

The text you entered is added to the test.pdf file and opened. You can close the PDF file, enter new text in the text box, and click the button. The new text appears in the PDF file that opens.