Develop Reference

How can i convert a file .png to a Bitmap? Nothing works for me. Error "'Failed to decode image. The provided image must be a Bitmap.'" Xamarin.forms

I'm working with Xamarin in the part of Xamarin.Forms i need to convert a file ("image.png") to a Bitmap because when project run its enter in "break mode" and show me this message "Java.Lang.IllegalArgumentException: 'Failed to decode image. The provided image must be a Bitmap.'". So i tried to convert the file in many ways like:
1_ Using methods from System.Drawing.Bitmap but it's show this exception "This operation is not supported in this platform"
2_ Cannot use Android.Graphics because i'm working in xamarin.forms not in xamarin.android.
3_ I tried to convert the "image.png" into a base64 or byte[] array and then into a bitmap but the problem is the same like in first problem because to convert from byte[] array or base64 to a Bitmap i have use methods from System.Drawing.Bitmap.
4_ I tried using the library SkiaSharp but i don't have success because i don't found so much information about how to convert .png to SKBitmap and then convert SKBitmap to Bitmap (even i don't know if this is possible).
5_ Finally i converted "image.png" to a "image.bmp" with an app and use the file .bmp in my project but it doesn't work too.
the "image.png" i have to save in a string variable, well that's the idea.
If you have a solution with SkiaSharp o whatever i will glad
EDIT
here is a part of my code, i just save in a variable the image
Icon = "pin_blue.png";
//i can't use a path because in xamarin you have many size from the same
//image for the different size of the screen
EDIT 2 This is my method to show the pins in google maps
private void ShowPins(List<PointsOfInterest> resultPointsOfInterest)
{
if (resultPointsOfInterest != null && resultPointsOfInterest.Any())
{
var location = Geolocation.GetLastKnownLocationAsync();
PointsOfInterest position = new PointsOfInterest();
if (location != null)
{
position.ccsm0166latitud = location.Result.Latitude;
position.ccsm0166longitud = location.Result.Longitude;
}
else {
position = resultPointsOfInterest.First();
}
//Distance = Distance.FromKilometers(new Random().Next(23,35));
Distance = Distance.FromKilometers(3);
Position = new Position(position.ccsm0166latitud, position.ccsm0166longitud);
PinsFiltered= Pins = new List<PinCustom>(resultPointsOfInterest.Select(
x => new PinCustom()
{
Position =
new Position(x.ccsm0166latitud, x.ccsm0166longitud),
Address = x.ccsm0166direccion,
Label = x.ccsm0166nombre,
Type = PinType.Place,
TypePointOfInterest = x.ccsm0166tipositio,
IconBM = Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.branch ? PinCustom.ConvertToBitmap("pin_blue.png") :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.branch ? "pin_blue.png" :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.branchWithExtendedHours ? "pin_black.png" :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.branchWithExtendedHours2 ? "pin_black.png" :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.branchWithExtendedHours3 ? "pin_black.png" :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.selfServiceTerminal ? "pin_green.png" :
Int32.Parse(x.ccsm0166tipositio) == (int)PointOfInterestType.atmServBox ? "pin_yellow.png" : string.Empty
}).ToList());
}
else
{
Pins = new List<PinCustom>();
}
}
This is the class Pin where i save the image
public class PinCustom : Pin
{
public string TypePointOfInterest { get; set; }
public string Icon { get; set; }
public Bitmap { get; set; }
//Here i create this variable to save a bitmap but i don't know if i do the things well
}
this is the icon .png i want to show in googlemaps
Pin Blue Image

To open your file and convert it to byte array:
string directory = Path.Combine(Android.OS.Environment.ExternalStorageDirectory.AbsolutePath, Android.OS.Environment.DirectoryDownloads);
// or your image directory, just replace it
var stream = File.OpenWrite(Path.Combine(directory, "image.png"));
byte[] buff = ConvertStreamToByteArray(stream);
stream.Close();
public static byte[] ConvertStreamToByteArray(Stream stream)
{
byte[] byteArray = new byte[16 * 1024];
using (MemoryStream mStream = new MemoryStream())
{
int bit;
while ((bit = stream.Read(byteArray, 0, byteArray.Length)) > 0)
{
mStream.Write(byteArray, 0, bit);
}
return mStream.ToArray();
}
}
then, to pass this byte array to SKBitmap:
SKBitmap bmp = SKBitmap.Decode(buff);
EDIT:
If you want to try without ConvertStreamToByteArray():
byte[] buff = null;
stream.Write(buff, 0, buff.Length);
This Write will depend of the type of your stream. In this example, I'm using FileStream.
EDIT 2:
string resourceID = "image.png";
Assembly assembly = GetType().GetTypeInfo().Assembly;
using (Stream stream = assembly.GetManifestResourceStream(resourceID))
{
resourceBitmap = SKBitmap.Decode(stream);
SKBitmap bmp = SKImage.FromBitmap(resourceBitmap);
}
and then you can use this bitmap to draw and fill your SKCanvas:
canvas.DrawBitmap(bmp, 0, 0);

Use ffmpeg
command for this: ffmpeg -i image.png image.bmp

i have 5 types of pins (pins are the image .png) when i put the pins
in format .png
if you want to custom the pins in your map, you can simply use Custom Renderers to achieve this.
The icon used to represent a marker can be customized by calling the MarkerOptions.SetIcon method. This can be accomplished by overriding the CreateMarker method, which is invoked for each Pin that's added to the map:
protected override MarkerOptions CreateMarker(Pin pin)
{
var marker = new MarkerOptions();
marker.SetPosition(new LatLng(pin.Position.Latitude, pin.Position.Longitude));
marker.SetTitle(pin.Label);
marker.SetSnippet(pin.Address);
marker.SetIcon(BitmapDescriptorFactory.FromResource(Resource.Drawable.pin));
return marker;
}
If you want to display different icons, you can refer to the following code:
protected override MarkerOptions CreateMarker(Pin pin)
{
var marker = new MarkerOptions();
marker.SetPosition(new LatLng(pin.Position.Latitude, pin.Position.Longitude));
marker.SetTitle(pin.Label);
marker.SetSnippet(pin.Address);
var customPin = (Element as CustomMap).CustomPins.FirstOrDefault(p => p.Position == pin.Position);
if (customPin != null)
{
if (customPin.IconType == "corporate")
{
marker.SetIcon(BitmapDescriptorFactory.FromResource(Resource.Drawable.corporate));
}
else if (customPin.IconType == "pickup")
{
marker.SetIcon(BitmapDescriptorFactory.FromResource(Resource.Drawable.bus));
}
}
return marker;
}
For more, check:Customizing the Marker.

How to make Generated gif in xamarin.ios slower?

I created a service used in my xamarin.forms project to generate a gif from four downloaded frame. The android side is working good, but I got a problem in iOs side, where gif is created but it's too fast, regardless of the set delay value. This is my class:
public class GifService : IGifService
{
public string CreateGif(string frame1Path, string frame2Path, string frame3Path, string frame4Path,string webId,string path="")
{
List<UIImage> listOfFrame = new List<UIImage>();
UIImage image1 = new UIImage(frame1Path);
listOfFrame.Add(image1);
UIImage image2 = new UIImage(frame2Path);
listOfFrame.Add(image2);
UIImage image3 = new UIImage(frame3Path);
listOfFrame.Add(image3);
UIImage image4 = new UIImage(frame4Path);
listOfFrame.Add(image4);
NSMutableDictionary fileProperties = new NSMutableDictionary();
fileProperties.Add(CGImageProperties.GIFLoopCount, new NSNumber(0));
NSMutableDictionary frameProperties = new NSMutableDictionary();
frameProperties.Add(CGImageProperties.GIFDelayTime, new NSNumber(5f));
NSUrl documentsDirectoryUrl = NSFileManager.DefaultManager.GetUrl(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomain.User,null, true,out _);
NSUrl fileUrl = documentsDirectoryUrl.Append(webId + ".gif",false);
var destination = CGImageDestination.Create(fileUrl, MobileCoreServices.UTType.GIF, 4);
destination.SetProperties(fileProperties);
foreach(var frame in listOfFrame)
{
var cgImage = frame.CGImage;
if(cgImage!= null)
{
destination.AddImage(cgImage, frameProperties);
}
}
if (!destination.Close())
{
Console.WriteLine("Failed to finalize the image destination");
}
return fileUrl.Path;
}
}
I think that the problem is CGImageProperties.GIFDelayTime that is ignored, but i don't know why. How can I resolve this problem?

After some tries, I found finally a solution to generate a gif with a desired delay. I don't know why, but in the way i showed in my question, the options are ignored.
Here a working solution:
public class GifService : IGifService
{
public string CreateGif(string frame1Path, string frame2Path, string frame3Path, string frame4Path,string webId,string path="")
{
List<UIImage> listOfFrame = new List<UIImage>();
UIImage image1 = new UIImage(frame1Path);
listOfFrame.Add(image1);
UIImage image2 = new UIImage(frame2Path);
listOfFrame.Add(image2);
UIImage image3 = new UIImage(frame3Path);
listOfFrame.Add(image3);
UIImage image4 = new UIImage(frame4Path);
listOfFrame.Add(image4);
NSMutableDictionary fileProperties = new NSMutableDictionary
{
{ CGImageProperties.GIFLoopCount, new NSNumber(1) }
};
NSUrl documentsDirectoryUrl = NSFileManager.DefaultManager.GetUrl(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomain.User,null, true,out _);
NSUrl fileUrl = documentsDirectoryUrl.Append(webId + ".gif",false);
var destination = CGImageDestination.Create(fileUrl, MobileCoreServices.UTType.GIF, 4);
destination.SetProperties(fileProperties);
foreach (var frame in listOfFrame)
{
//difference is here, i create a var option and i set the
//GifDictionary
var options = new CGImageDestinationOptions();
options.GifDictionary = new NSMutableDictionary();
options.GifDictionary[CGImageProperties.GIFDelayTime] = new NSNumber(1f);
var cgImage = frame.CGImage;
if(cgImage!= null)
{
destination.AddImage(cgImage, options);
}
}
if (!destination.Close())
{
Console.WriteLine("Failed to finalize the image destination");
}
return fileUrl.Path;
}
}

How to Upload document in acumatica screen using acumatica web service

I am new to using acumatica web service. is it possible to upload a document/ file in specific screen as attachment like business account attachment.
eg. below screen in which we add manually.

I find the solution and posted to help anyone.
To upload any file we must convert that file into bytes and submit bytes which convert your file.
//Get bytes of file
byte[] filedata;
using(System.IO.FileStream file =
System.IO.File.Open(#"D:\Test.pdf",System.IO.FileMode.Open))
{
filedata = new byte[file.Length];
file.Read(filedata,0,filedata.Length);
}
// Import Data Now to Business Account
BAccount.CR303000ImportResult[] lstObjContent = context.CR303000Import
(
new BAccount.Command[]
{
// Must Pass BusinessAccount in which we want to update or add data
new BAccount.Value { Value="XXXXXX",LinkedCommand=objContent.AccountSummary.BusinessAccount},
new BAccount.Value { Value="TestValue123",LinkedCommand=objContent.AccountSetup.CurrentMethod},
new BAccount.Value { FieldName="NameOfFileWithExtension",LinkedCommand=objContent.AccountSummary.ServiceCommands.Attachment},
objContent.Actions.Save
},null,new string[][] { new string[] { Convert.ToBase64String(filedata) },new string[] { Convert.ToBase64String(filedata) },}
,false,false,true
);

Even the below code works. Verified in version 18R1.
var content = _context.CR306000GetSchema(); _context.CR306000Clear();
var commands = new List();
ReqParameter(content, ref commands);
commands.Add(content.Actions.Save);
commands.Add(content.CaseSummary.CaseID);
var orderResults = _context.CR306000Submit(commands.ToArray());
private static void ReqParameter(CR306000Content content, ref List<Command> cmds)
{
if (cmds == null) throw new ArgumentNullException("cmds");
byte[] filedata= null;
Uri uri = new Uri("https://acmdev.baccahq.com/Icons/login_bg5.jpg"); // change the required url of the data that has to be fetched
if (uri.IsFile)
{
string filename = System.IO.Path.GetFileName(uri.LocalPath);
filedata = System.Text.Encoding.UTF8.GetBytes(uri.LocalPath);
}
if (filedata == null)
{
WebClient wc = new WebClient();
filedata = wc.DownloadData(uri);
}
cmds = new List<Command>
{
//Case Header Details
new Value { Value="<NEW>",LinkedCommand = content.CaseSummary.CaseID},
new Value { Value="L41",LinkedCommand = content.CaseSummary.ClassID},
new Value { Value="ABCSTUDIOS",LinkedCommand = content.CaseSummary.BusinessAccount, Commit = true},
new Value { Value="Test subject created from envelop call 11C",LinkedCommand = content.CaseSummary.Subject},
// body of the case
new Value{Value= "Body of the content for created through envelop call 11B", LinkedCommand = content.Details.Description},
//Attaching a file
new Value
{
Value = Convert.ToBase64String(filedata), // byte data that is passed to through envelop
FieldName = "Test.jpg",
LinkedCommand =
content.CaseSummary.ServiceCommands.Attachment
},
};
}

xamarin android ListView with image

Im tring to load data from database and display on a ListView.
The list view contains 2 textview and 1 image view. Im using SQlite.net.
Where is my databse:
Database
public class contacts
{
[PrimaryKey, AutoIncrementAttribute, Column("id")]
public int id {get; set;}
public string name {get; set;}
public string number { get; set; }
public byte[] photo{ get; set; }
}
And where is my function to fill the listview:
private void refreshListView()
{
var db = new SQLiteConnection (MainActivity._DatabaseConnectString);
MatrixCursor mMatrixCursor = new MatrixCursor (new String[]{ "_id", "name", "number", "photo" });
SimpleCursorAdapter adap;
adap = new SimpleCursorAdapter (
this,
Resource.Layout.lv_layout,
null,
new String[]{ "name", "number", "photo" },
new int[]{ Resource.Id.tv_name, Resource.Id.tv_number, Resource.Id.iv_photo }, 0);
IEnumerable<contacts> table = db.Query<contacts> ("select * from contacts");
foreach (var contact in table) {
mMatrixCursor.AddRow (new Java.Lang.Object[] {contact.id,
contact.name, contact.number, BitmapFactory.DecodeByteArray (contact.photo, 0, contact.photo.Length)
});
}
lview.Adapter = adap;
adap.SwapCursor (mMatrixCursor);
}
The only problem is the image dont show and I have this error from the output:
[BitmapFactory] Unable to decode stream: java.io.FileNotFoundException: /android.graphics.Bitmap#42087da0: open failed: ENOENT (No such file or directory)
[System.out] resolveUri failed on bad bitmap uri: android.graphics.Bitmap#42087da0
I already done this application with java for android and I fix that problem with the this code but I dont know how to "translate" the code from java to c#.
Where is the java code below the adap:
adap.setViewBinder(new SimpleCursorAdapter.ViewBinder() {
#Override
public boolean setViewValue(View view, Cursor cursor, int i) {
if (view.getId() == R.id.iv_photo) {
byte[] Blobdata = cursor.getBlob(i);
Bitmap bitmap = Bitmap.createScaledBitmap(BitmapFactory.decodeByteArray(
Blobdata, 0, Blobdata.length), 150, 150, false);
((ImageView) view).setImageBitmap(bitmap);
return true;
} else {
return false;
}
}
});
Somebody can help me "translate" this code to c#? or use another code.
Thanks from the help and sorry my english.
EDITED 2
Ok where is the code translated to c#
class ViewBinder : Java.Lang.Object, SimpleCursorAdapter.IViewBinder
{
public bool SetViewValue (View view, Android.Database.ICursor cursor, int i)
{
if (view.Id == Resource.Id.iv_photo) {
byte[] Blobdata = cursor.GetBlob (i);
Bitmap bitmap = Bitmap.CreateScaledBitmap (BitmapFactory.DecodeByteArray (
Blobdata, 0, Blobdata.Length), 150, 150, false);
((ImageView)view).SetImageBitmap (bitmap);
return true;
} else {
return false;
}
}
}
But now I got an error in this line:
byte[] Blobdata = cursor.GetBlob (i);
Error:
android.graphics.Bitmap cannot be cast to byte[]
I think im getting this error becouse in my database im not using Blob but byte array. Somebody know how I can retrive byte array from database or how i can use Blob data type?

You can store a byte-array in a BLOB.
This is how I fetch it:
using (SqliteDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
images.Add(new Image((byte[])reader["Image"]));
}
}
I can then use my Image property ImageByteArray to convert it to a Bitmap, similar to the way you did.
Bitmap image = BitmapFactory.DecodeByteArray(data, 0, barray.Length);
The Bitmap is then ready to show in an ImageView.
imageView.SetImageBitmap(image);
As you can see, our methods are very much alike. So to me it seems cursor.GetBlob (i) returns something unexpected.
public abstract byte[] getBlob (int columnIndex)
Added in API level 1
Returns the value of the requested column as a byte array.
The result and whether this method throws an exception when the column value is null or the column type is not a blob type is implementation-defined.
Parameters:
columnIndex the zero-based index of the target column.
Returns:
the value of that column as a byte array.
(http://developer.android.com/reference/android/database/Cursor.html#getBlob(int))
According to the description from the method, it seems your column does not hold a BLOB/byte-array.
Use var Blobdata = cursor.GetBlob (i); to find out what is in it, and adjust accordingly.

How to Add 'Comments' to a JPEG File Using C#

Within the property window of a JPEG image, there is a tab called 'Summary'. Within this tab, there is a field called 'Comments' I would like to write some c# code which will add a given string to this field e.g "This is a photo".
Does some kind soul out there know how to do this?
Many thanks.

Based on other answers I wrote the following class which allows various metadata manipulations. You use it like this:
var jpeg = new JpegMetadataAdapter(pathToJpeg);
jpeg.Metadata.Comment = "Some comments";
jpeg.Metadata.Title = "A title";
jpeg.Save(); // Saves the jpeg in-place
jpeg.SaveAs(someNewPath); // Saves with a new path
The differences between my solution and the others are not large. Principally I have refactored this to be cleaner. I also use the higher level properties of BitmapMetadata, rather than the SetQuery method.
Here is the full code, which is licensed under the MIT licence. You will need to add references to PresentationCore, WindowsBase, and System.Xaml.
public class JpegMetadataAdapter
{
private readonly string path;
private BitmapFrame frame;
public readonly BitmapMetadata Metadata;
public JpegMetadataAdapter(string path)
{
this.path = path;
frame = getBitmapFrame(path);
Metadata = (BitmapMetadata)frame.Metadata.Clone();
}
public void Save()
{
SaveAs(path);
}
public void SaveAs(string path)
{
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(frame, frame.Thumbnail, Metadata, frame.ColorContexts));
using (Stream stream = File.Open(path, FileMode.Create, FileAccess.ReadWrite))
{
encoder.Save(stream);
}
}
private BitmapFrame getBitmapFrame(string path)
{
BitmapDecoder decoder = null;
using (Stream stream = File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
{
decoder = new JpegBitmapDecoder(stream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
}
return decoder.Frames[0];
}
}

The following code solves my problem and adds comments to a given JPEG image:
public void addImageComment(string imageFlePath, string comments)
{
string jpegDirectory = Path.GetDirectoryName(imageFlePath);
string jpegFileName = Path.GetFileNameWithoutExtension(imageFlePath);
BitmapDecoder decoder = null;
BitmapFrame bitmapFrame = null;
BitmapMetadata metadata = null;
FileInfo originalImage = new FileInfo(imageFlePath);
if (File.Exists(imageFlePath))
{
// load the jpg file with a JpegBitmapDecoder
using (Stream jpegStreamIn = File.Open(imageFlePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
{
decoder = new JpegBitmapDecoder(jpegStreamIn, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
}
bitmapFrame = decoder.Frames[0];
metadata = (BitmapMetadata)bitmapFrame.Metadata;
if (bitmapFrame != null)
{
BitmapMetadata metaData = (BitmapMetadata)bitmapFrame.Metadata.Clone();
if (metaData != null)
{
// modify the metadata
metaData.SetQuery("/app1/ifd/exif:{uint=40092}", comments);
// get an encoder to create a new jpg file with the new metadata.
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapFrame, bitmapFrame.Thumbnail, metaData, bitmapFrame.ColorContexts));
//string jpegNewFileName = Path.Combine(jpegDirectory, "JpegTemp.jpg");
// Delete the original
originalImage.Delete();
// Save the new image
using (Stream jpegStreamOut = File.Open(imageFlePath, FileMode.CreateNew, FileAccess.ReadWrite))
{
encoder.Save(jpegStreamOut);
}
}
}
}
}
This is essentially a lightly modified version of the code found under the link which Konamiman kindly supplied.
Please be aware that to make this work you will need to add .NET references to PresentationCore and WindowsBase. If using Visual Studio 2008, this can be achieved via the following:
Right click on your project in the Solution Explorer
From the drop down list, select Add 'Reference...'
From the new box which opens, select the '.NET' tab
Scroll to the two references mentioned above and on each, click ok
Many thanks to both danbystrom and Konamiman for your help in this matter. I really appreciate the quick response.

The easy part:
Add this property item:
var data = System.Text.Encoding.UTF8.GetBytes( "Some comments" );
PropertyItem pi;
*** create an empty PropertyItem here
pi.Type = 2;
pi.Id = 37510;
pi.Len = data.Length;
pi.Value = data;
To the Image's PropertItems collection.
The somewhat more cumbersome part:
How do you create a new PropertyItem, since it has no public constructor?
The common "trick" is to have an empty image lying around from which you can steal a PropertyItem. sigh

Thanks to the answers here, I've coded a solution to set a comment using memory only:
public static Image SetImageComment(Image image, string comment) {
using (var memStream = new MemoryStream()) {
image.Save(memStream, ImageFormat.Jpeg);
memStream.Position = 0;
var decoder = new JpegBitmapDecoder(memStream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
BitmapMetadata metadata;
if (decoder.Metadata == null) {
metadata = new BitmapMetadata("jpg");
} else {
metadata = decoder.Metadata;
}
metadata.Comment = comment;
var bitmapFrame = decoder.Frames[0];
BitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapFrame, bitmapFrame.Thumbnail, metadata, bitmapFrame.ColorContexts));
var imageStream = new MemoryStream();
encoder.Save(imageStream);
imageStream.Position = 0;
image.Dispose();
image = null;
return Image.FromStream(imageStream);
}
}
Don't forget to dispose the image that is returned by this method. (For example after saving the image to a file)

Thanks to the previous tips I was able to put the following together. I've tested it and it seems to work. One of the biggest stumbling blocks was determining the Id needed for the field you want to assign.
string fileName = "c:/SomeImage.jpg";
// Retrieve the Image
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(fileName);
// Get the list of existing PropertyItems. i.e. the metadata
PropertyItem[] properties = originalImage.PropertyItems;
// Create a bitmap image to assign attributes and do whatever else..
Bitmap bmpImage = new Bitmap((Bitmap)originalImage);
// Don't need this anymore
originalImage.Dispose();
// Get / setup a PropertyItem
PropertyItem item = properties[0]; // We have to copy an existing one since no constructor exists
// This will assign "Joe Doe" to the "Authors" metadata field
string sTmp = "Joe DoeX"; // The X will be replaced with a null. String must be null terminated.
var itemData = System.Text.Encoding.UTF8.GetBytes(sTmp);
itemData[itemData.Length - 1] = 0;// Strings must be null terminated or they will run together
item.Type = 2; //String (ASCII)
item.Id = 315; // Author(s), 315 is mapped to the "Authors" field
item.Len = itemData.Length; // Number of items in the byte array
item.Value = itemData; // The byte array
bmpImage.SetPropertyItem(item); // Assign / add to the bitmap
// This will assign "MyApplication" to the "Program Name" field
sTmp = "MyApplicationX";
itemData = System.Text.Encoding.UTF8.GetBytes(sTmp);
itemData[itemData.Length - 1] = 0; // Strings must be null terminated or they will run together
item.Type = 2; //String (ASCII)
item.Id = 305; // Program Name, 305 is mapped to the "Program Name" field
item.Len = itemData.Length;
item.Value = itemData;
bmpImage.SetPropertyItem(item);
// Save the image
bmpImage.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
//Clean up
bmpImage.Dispose();

A variant on Peter Kistler's solution to set Title, Subject and Comment. I found I had to create items as Unicode byte array (type 1) and the IDs for Title, Subject and Comment are the same as for EXIF XPTitle, XPSubject and XP Comment. sFileOut can be the same as sFile.
public static void SetWindowsTags2(string sFile, string sFileOut, string Title = "", string Subject = "", string Comment = "", bool bShowError = false)
{
try
{
// Retrieve the Image
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(sFile);
// Get the list of existing PropertyItems. i.e. the metadata
PropertyItem[] properties = originalImage.PropertyItems;
/*foreach (PropertyItem propItem in properties)
{
string sTag = System.Text.Encoding.UTF8.GetString(propItem.Value);
string sItem = sTag.Replace("\0", string.Empty);
Debug.Print(propItem.Id.ToString() + ", " + propItem.Type + ", " + sItem);
}*/
// Create a bitmap image to assign attributes and do whatever else..
Bitmap bmpImage = new Bitmap((Bitmap)originalImage);
// Don't need this anymore
originalImage.Dispose();
// Get / setup a PropertyItem
PropertyItem item = properties[0]; // We have to copy an existing one since no constructor exists
var itemData = System.Text.Encoding.Unicode.GetBytes(Title);
itemData[itemData.Length - 1] = 0;// Strings must be null terminated or they will run together
item.Type = 1; //Unicode Byte Array
item.Id = 40091; // Title ID
item.Len = itemData.Length; // Number of items in the byte array
item.Value = itemData; // The byte array
bmpImage.SetPropertyItem(item); // Assign / add to the bitmap
itemData = System.Text.Encoding.Unicode.GetBytes(Subject);
itemData[itemData.Length - 1] = 0; // Strings must be null terminated or they will run together
item.Type = 1; //Unicode Byte Array
item.Id = 40095; // subject
item.Len = itemData.Length;
item.Value = itemData;
bmpImage.SetPropertyItem(item); // Assign / add to the bitmap
itemData = System.Text.Encoding.Unicode.GetBytes(Comment);
itemData[itemData.Length - 1] = 0; // Strings must be null terminated or they will run together
item.Type = 1; ////Unicode Byte Array
item.Id = 40092; // comment
item.Len = itemData.Length;
item.Value = itemData;
bmpImage.SetPropertyItem(item); // Assign / add to the bitmap
// Save the image
bmpImage.Save(sFileOut, System.Drawing.Imaging.ImageFormat.Jpeg);
//Clean up
bmpImage.Dispose();
}
catch (Exception Ex)
{
}
}