Silverlight Simple Drag And Drop / Or Browse View Model / MVVM File Upload Control

// Copyright (c) 2010
// by OpenLight Group
// http://openlightgroup.net/
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
// documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
// the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and 
// to permit persons to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions 
// of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
//
// CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Data;
using System.ComponentModel;
using System.IO;
using System.Windows.Input;
using System.Windows;

namespace SimpleMVVMFileUpload
{
    public class ADefUploadControlViewModel : INotifyPropertyChanged
    {
        public Uri UploadUrl { get; set; }

        public ADefUploadControlViewModel()
        {
            // Set the command property
            UploadFileCommand = new DelegateCommand(UploadFile, CanUploadFile);
        }

        // Commands

        #region UploadFileCommand
        public ICommand UploadFileCommand { get; set; }
        public void UploadFile(object param)
        {
            // Can only upload if there is a selected File
            if (SelectedFileProperty != null)
            {         
                // Turn on Uploading Flag
                Uploading = true;

                UploadFile();
            }
        }

        private bool CanUploadFile(object param)
        {
            // Only allow uploading if not already uploading
            return (Uploading != true);
        }
        #endregion

        // Properties

        #region Uploading
        private bool _Uploading = false;
        public bool Uploading
        {
            get
            {
                return _Uploading;
            }
            set
            {
                if (Uploading == value)
                {
                    return;
                }
                _Uploading = value;
                this.NotifyPropertyChanged("Uploading");
            }
        }
        #endregion

        #region SelectedFileProperty
        private FileInfo _SelectedFileProperty;
        public FileInfo SelectedFileProperty
        {
            get
            {
                return _SelectedFileProperty;
            }
            set
            {
                if (SelectedFileProperty == value)
                {
                    return;
                }
                _SelectedFileProperty = value;
                this.NotifyPropertyChanged("SelectedFileProperty");
            }
        }
        #endregion

        #region SelectedFileNameProperty
        private string _SelectedFileNameProperty = "File Name";
        public string SelectedFileNameProperty
        {
            get
            {
                return _SelectedFileNameProperty;
            }
            set
            {
                if (SelectedFileNameProperty == value)
                {
                    return;
                }
                _SelectedFileNameProperty = value;
                this.NotifyPropertyChanged("SelectedFileNameProperty");
            }
        }
        #endregion

        #region FileuploadPercentProperty
        private string _FileuploadPercentProperty;
        public string FileuploadPercentProperty
        {
            get
            {
                return string.Format("{0} %", this._FileuploadPercentProperty);
            }
            set
            {
                this._FileuploadPercentProperty = value;
                this.NotifyPropertyChanged("FileuploadPercentProperty");
            }
        }
        #endregion

        #region MainViewModell_VM
        private MainViewModel _MainViewModell_VM;
        public MainViewModel MainViewModell_VM
        {
            get
            {
                return _MainViewModell_VM;
            }
            set
            {
                if (MainViewModell_VM == value)
                {
                    return;
                }
                _MainViewModell_VM = value;
                this.NotifyPropertyChanged("MainViewModell_VM");
            }
        }
        #endregion

        // Upload File

        #region UploadFile
        private void UploadFile()
        {
            // If there is a file upload it
            if (SelectedFileProperty != null)
            {
                // Get the upload URL
                string strURLWithSelectedFolder = string.Format("{0}", GetWebserviceAddress());
                Uri uri = new Uri(strURLWithSelectedFolder, UriKind.Absolute);
                UploadUrl = uri;

                // Create an FileUpload object
                FileUpload upload = new FileUpload(App.Current.RootVisual.Dispatcher, UploadUrl, SelectedFileProperty);
                upload.ChunkSize = 4194304;

                // Wire up handles for status changed and upload percentage
                // These will be updating the properties that the ViewModel exposes
                upload.StatusChanged += new EventHandler(upload_StatusChanged);
                upload.UploadProgressChanged += new ProgressChangedEvent(upload_UploadProgressChanged);

                // Start the Upload
                upload.Upload();
            }
        }
        #endregion

        // Uploading Events

        #region upload_UploadProgressChanged
        void upload_UploadProgressChanged(object sender, UploadProgressChangedEventArgs args)
        {
            // Update the progress percentage
            FileuploadPercentProperty = args.ProgressPercentage.ToString();
        }
        #endregion

        #region upload_StatusChanged
        void upload_StatusChanged(object sender, EventArgs e)
        {
            FileUpload fu = sender as FileUpload;
            
            // Is upload complete?
            if (fu.Status == FileUploadStatus.Complete)
            {                
                // Clear the Selected File
                SelectedFileProperty = null;

                // Turn off Uploading Flag
                Uploading = false;

                // Refresh Files on the Main page
                MainViewModell_VM.GetFilesCommand.Execute(null);
            }
        }
        #endregion

        // Utility

        #region GetWebserviceAddress
        private string GetWebserviceAddress()
        {
            string strXapFile = @"/ClientBin/SimpleMVVMFileUpload.xap";

            string strBaseWebAddress =
                App.Current.Host.Source.AbsoluteUri.Replace(strXapFile, "");

            return string.Format(@"{0}/{1}", strBaseWebAddress, @"WebService/FileUpload.ashx");
        }
        #endregion

        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
        #endregion
    }
}