Work on FileIO class (#28)

source/Windows.Storage/FileIO.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Runtime.CompilerServices;
+using Windows.Storage.Streams;
 
 namespace Windows.Storage
 {
@@ -33,10 +34,24 @@ public static class FileIO
 
         //        }
 
-        //        ReadBufferAsync(IStorageFile)
-        //        {
-
-        //        }
+        /// <summary>
+        /// Reads the contents of the specified file and returns a buffer.
+        /// </summary>
+        /// <param name="file">The file to read.</param>
+        /// <returns>
+        /// When this method completes, it returns an object (type <see cref="IBuffer"/>) that represents the contents of the file.
+        /// </returns>
+        ///<remarks>
+        /// This method is exclusive of nanoFramework and it's not available in the UWP API.
+        /// The equivalent method would be ReadBufferAsync(IStorageFile).
+        ///</remarks>
+        public static IBuffer ReadBuffer(IStorageFile file)
+        {
+            byte[] tempBuffer = null;
+            ReadBufferNative(file, ref tempBuffer);
+            ByteBuffer buffer = new ByteBuffer(tempBuffer);
+            return (IBuffer)buffer;
+        }
 
         //        ReadLinesAsync(IStorageFile)
         //        {
@@ -61,24 +76,46 @@ public static class FileIO
         /// This method is exclusive of nanoFramework and it's not available in the UWP API.
         /// The equivalent method would be ReadTextAsync(IStorageFile).
         ///</remarks>
-        [System.Diagnostics.DebuggerStepThrough]
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        public extern static String ReadText(IStorageFile file);
+        public static String ReadText(IStorageFile file)
+        {
+            String text = null;
 
-        //        ReadTextAsync(IStorageFile, UnicodeEncoding)
-        //        {
+            ReadTextNative(file, ref text);
 
-        //        }
+            return text;
+        }
 
-        //        WriteBufferAsync(IStorageFile, IBuffer)
+        //        ReadTextAsync(IStorageFile, UnicodeEncoding)
         //        {
 
         //        }
 
-        //        WriteBytesAsync(IStorageFile, Byte[])
-        //        {
+        /// <summary>
+        /// Writes data from a buffer to the specified file.
+        /// </summary>
+        /// <param name="file">The file that the buffer of data is written to.</param>
+        /// <param name="buffer">The buffer that contains the data to write.</param>
+        ///<remarks>
+        /// This method is exclusive of nanoFramework and it's not available in the UWP API.
+        /// The equivalent method would be WriteBuffer(IStorageFile, IBuffer).
+        ///</remarks>
+        public static void WriteBuffer(IStorageFile file, IBuffer buffer)
+        {
+            WriteBytes(file, ((ByteBuffer)buffer).Data);
+        }
 
-        //        }
+        /// <summary>
+        /// Writes an array of bytes of data to the specified file.
+        /// </summary>
+        /// <param name="file">The file that the byte is written to.</param>
+        /// <param name="buffer">The array of bytes to write.</param>
+        ///<remarks>
+        /// This method is exclusive of nanoFramework and it's not available in the UWP API.
+        /// The equivalent method would be WriteBytesAsync(IStorageFile, Byte[]).
+        ///</remarks>
+        [System.Diagnostics.DebuggerStepThrough]
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        public extern static void WriteBytes(IStorageFile file, Byte[] buffer);
 
         //        WriteLinesAsync(IStorageFile, IIterable<String>)
         //        {
@@ -112,5 +149,17 @@ public static class FileIO
         //        {
 
         //        }
+
+        #region Native calls
+
+        [System.Diagnostics.DebuggerStepThrough]
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        private extern static void ReadBufferNative(IStorageFile file, ref byte[] buffer);
+        [System.Diagnostics.DebuggerStepThrough]
+
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        public extern static void ReadTextNative(IStorageFile file, ref string text);
+        #endregion
+
     }
 }

source/Windows.Storage/Windows.Storage.nfproj

@@ -129,6 +129,7 @@
     <Reference Include="Windows.Storage.Streams, Version=1.0.5.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
       <HintPath>..\packages\nanoFramework.Windows.Storage.Streams.1.0.5-preview-008\lib\Windows.Storage.Streams.dll</HintPath>
       <Private>True</Private>
+      <SpecificVersion>True</SpecificVersion>
     </Reference>
   </ItemGroup>
   <Import Project="$(NanoFrameworkProjectSystemPath)NFProjectSystem.CSharp.targets" Condition="Exists('$(NanoFrameworkProjectSystemPath)NFProjectSystem.CSharp.targets')" />
@@ -144,4 +145,4 @@
     </PropertyGroup>
     <Error Condition="!Exists('..\packages\Nerdbank.GitVersioning.3.0.6-beta\build\Nerdbank.GitVersioning.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Nerdbank.GitVersioning.3.0.6-beta\build\Nerdbank.GitVersioning.targets'))" />
   </Target>
-</Project>
+</Project>

source/Windows.Storage/Windows.Storage.previous.nugetreferenceswitcher

@@ -0,0 +1 @@
+Windows.Storage.Streams	../../../nflib-Windows.Storage.Streams/source/Windows.Storage.Streams/Windows.Storage.Streams.nfproj	../packages/nanoFramework.Windows.Storage.Streams.1.0.5-preview-006/lib/Windows.Storage.Streams.dll

tests/FileAccess/FileAccess.nfproj

@@ -20,6 +20,7 @@
   <ItemGroup>
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Scenario4_WriteAndReadBytesInAFile.cs" />
     <Compile Include="Scenario3_WriteAndReadTextInAFile.cs" />
     <Compile Include="Scenario2_CreateAFileInRemovableStorage.cs" />
     <Compile Include="Scenario1_CreateAFolderInRemovableStorage.cs" />
@@ -30,6 +31,11 @@
       <Private>True</Private>
       <SpecificVersion>True</SpecificVersion>
     </Reference>
+    <Reference Include="Windows.Storage.Streams, Version=1.0.5.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
+      <HintPath>..\..\source\packages\nanoFramework.Windows.Storage.Streams.1.0.5-preview-008\lib\Windows.Storage.Streams.dll</HintPath>
+      <Private>True</Private>
+      <SpecificVersion>True</SpecificVersion>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />

tests/FileAccess/FileAccess.previous.nugetreferenceswitcher

@@ -0,0 +1 @@
+Windows.Storage.Streams	../../../nflib-Windows.Storage.Streams/source/Windows.Storage.Streams/Windows.Storage.Streams.nfproj	../../source/packages/nanoFramework.Windows.Storage.Streams.1.0.5-preview-006/lib/Windows.Storage.Streams.dll

tests/FileAccess/Program.cs

@@ -23,6 +23,9 @@ public static void Main()
             // write text and read to/from a file
             Scenario3_WriteAndReadTextInAFile.Execute();
 
+            // write bytes and read to/from a file
+            Scenario4_WriteAndReadBytesInAFile.Execute();
+
             Thread.Sleep(Timeout.Infinite);
         }
     }

tests/FileAccess/Scenario3_WriteAndReadTextInAFile.cs

@@ -12,6 +12,8 @@ public class Scenario3_WriteAndReadTextInAFile
     {
         public static void Execute()
         {
+            string textFromFile = null;
+
             // Get the logical root folder for all removable storage devices
             // in nanoFramework the drive letters are fixed, being:
             // D: SD Card
@@ -43,14 +45,22 @@ public static void Execute()
                 try
                 {
                     // read text from the file
-                    var textFromFile = FileIO.ReadText(myFile);
+                    textFromFile = FileIO.ReadText(myFile);
                 }
                 catch (Exception ex)
                 {
-                    Console.WriteLine($"ERROR: write operation on file failed.");
+                    Console.WriteLine($"ERROR: read operation on file failed.");
                 }
 
-
+                // compare
+                if(textContent.GetHashCode() == textFromFile.GetHashCode())
+                {
+                    Console.WriteLine($"OK: read text matches written text.");
+                }
+                else
+                {
+                    Console.WriteLine($"ERROR: read text does not match written text.");
+                }
             }
             else
             {

tests/FileAccess/Scenario4_WriteAndReadBytesInAFile.cs

@@ -0,0 +1,69 @@
+//
+// Copyright (c) 2019 The nanoFramework project contributors
+// See LICENSE file in the project root for full license information.
+//
+
+using System;
+using Windows.Storage;
+using Windows.Storage.Streams;
+
+namespace FileAccess
+{
+    public class Scenario4_WriteAndReadBytesInAFile
+    {
+        public static void Execute()
+        {
+            string textFromFile = null;
+
+            // Get the logical root folder for all removable storage devices
+            // in nanoFramework the drive letters are fixed, being:
+            // D: SD Card
+            // E: USB Mass Storage Device
+            StorageFolder externalDevices = Windows.Storage.KnownFolders.RemovableDevices;
+
+            // list all removable storage devices
+            var removableDevices = externalDevices.GetFolders();
+
+            if (removableDevices.Length > 0)
+            {
+                // create a file
+                var myFile = removableDevices[0].CreateFile("data-file-with-content.bin", CreationCollisionOption.ReplaceExisting);
+
+                Console.WriteLine($"OK: Successfully created file: {myFile.Path}");
+
+                string userContent = "this is a string to be saved as binary data";
+
+                IBuffer writeBuffer = GetBufferFromString(userContent);
+                FileIO.WriteBuffer(myFile, writeBuffer);
+
+                Console.WriteLine($"The following { writeBuffer.Length } bytes of text were written to '{myFile.Name}':\r\n{ userContent }");
+
+                IBuffer readBuffer = FileIO.ReadBuffer(myFile);
+                using (DataReader dataReader = DataReader.FromBuffer(readBuffer))
+                {
+                    string fileContent = dataReader.ReadString(readBuffer.Length);
+
+                    Console.WriteLine($"The following {readBuffer.Length} bytes of text were read from '{myFile.Name}':\r\n{ fileContent }");
+                }
+            }
+            else
+            {
+                // there is no removable device present
+                Console.WriteLine($"ERROR: Can't create file. There is no removable device present.");
+            }
+        }
+
+        private static IBuffer GetBufferFromString(String str)
+        {
+            using (InMemoryRandomAccessStream memoryStream = new InMemoryRandomAccessStream())
+            {
+                using (DataWriter dataWriter = new DataWriter(memoryStream))
+                {
+                    dataWriter.WriteString(str);
+
+                    return dataWriter.DetachBuffer();
+                }
+            }
+        }
+    }
+}

tests/FileAccess/packages.config

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="nanoFramework.CoreLibrary" version="1.1.1" targetFramework="netnanoframework10" />
+  <package id="nanoFramework.Windows.Storage.Streams" version="1.0.5-preview-008" targetFramework="netnanoframework10" />
 </packages>