C# – How to find out when a picture was actually taken in C# running on Vista

c++

In windows XP "FileInfo.LastWriteTime" will return the date a picture is taken – regardless of how many times the file is moved around in the filesystem.

In Vista it instead returns the date that the picture is copied from the camera.

How can I find out when a picture is taken in Vista? In windows explorer this field is referred to as "Date Taken".

Best Solution

Here's as fast and clean as you can get it. By using FileStream, you can tell GDI+ not to load the whole image for verification. It runs over 10 × as fast on my machine.

//we init this once so that if the function is repeatedly called
//it isn't stressing the garbage man
private static Regex r = new Regex(":");

//retrieves the datetime WITHOUT loading the whole image
public static DateTime GetDateTakenFromImage(string path)
{
    using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
    using (Image myImage = Image.FromStream(fs, false, false))
    {
        PropertyItem propItem = myImage.GetPropertyItem(36867);
        string dateTaken = r.Replace(Encoding.UTF8.GetString(propItem.Value), "-", 2);
        return DateTime.Parse(dateTaken);
    }
}

And yes, the correct id is 36867, not 306.

The other Open Source projects below should take note of this. It is a huge performance hit when processing thousands of files.

Related Solutions

C# – How to find the method that called the current method

Try this:

using System.Diagnostics;
// Get call stack
StackTrace stackTrace = new StackTrace(); 
// Get calling method name
Console.WriteLine(stackTrace.GetFrame(1).GetMethod().Name);

one-liner:

(new System.Diagnostics.StackTrace()).GetFrame(1).GetMethod().Name

It is from Get Calling Method using Reflection [C#].

C# – Convert UTC/GMT time to local time

For strings such as 2012-09-19 01:27:30.000, DateTime.Parse cannot tell what time zone the date and time are from.

DateTime has a Kind property, which can have one of three time zone options:

Unspecified
Local
Utc

NOTE If you are wishing to represent a date/time other than UTC or your local time zone, then you should use DateTimeOffset.

So for the code in your question:

DateTime convertedDate = DateTime.Parse(dateStr);

var kind = convertedDate.Kind; // will equal DateTimeKind.Unspecified

You say you know what kind it is, so tell it.

DateTime convertedDate = DateTime.SpecifyKind(
    DateTime.Parse(dateStr),
    DateTimeKind.Utc);

var kind = convertedDate.Kind; // will equal DateTimeKind.Utc

Now, once the system knows its in UTC time, you can just call ToLocalTime:

DateTime dt = convertedDate.ToLocalTime();

This will give you the result you require.

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Related Solutions

C# – How to find the method that called the current method

C# – Convert UTC/GMT time to local time

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