WP7 - Formatting DateTime. How?

Question

I was wondering if there is a way to format datetime to the way i want it. So basically my scenarios is that when my app gets a file from the isolated storage it shows the date as "Hours:Minutes". I want it so that when the app gets the date it shows as "Hours:Date" but after a day it shows it as "Day/Month" how can i do this?

Soo far this is what i got:

Dim Storage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
        Dim directory As String = "./MyNote/SavedNotes/*.*"
        Dim filenames As String() = Storage.GetFileNames(directory)
        Dim dataSource As New List(Of SampleData)()
        For Each filename As String In filenames
            Dim ISF As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
            Dim FS As IsolatedStorageFileStream = ISF.OpenFile("MyNote/SavedNotes/" & filename, FileMode.Open, FileAccess.Read)
            Using SR As New StreamReader(FS)
                Dim FTime As String = Storage.GetCreationTime("MyNote/SavedNotes/" & filename).ToString("d/M ddd")
                Dim DATESS As String = SR.ReadLine
                Dim ReadName As String = SR.ReadLine
                dataSource.Add(New SampleData() With {.FileNameX = filename, .Description = ReadName, .FileTime = FTime})
            End Using
            SavedNotesList.ItemsSource = dataSource
        Next

More or less like the native messaging app. The date formats depending on when the message was received.

Answer 1

You might need to create some utility functions for these... the format of the date and time on your phone depends on the culture and localization of your phone. Something along the line of the code below is a start. let me know if you need VB examples, date formats documentation can be found here

        /// <summary>
    /// Get's a date description
    /// </summary>
    /// <param name="dateTime">
    /// The date to compare
    /// </param>
    /// <returns>
    /// A date description.
    /// </returns>
    public string GetRelativeTime(DateTime dateTime)
    {
        var timeMode = GetTimeMode(dateTime);

        switch (timeMode)
        {
          case TimeMode.Seconds:
          case TimeMode.Minutes:
          case TimeMode.Hours:
              return dateTime.ToString("HH:mm");
            default:
              return dateTime.ToString("dd/MM");;
        }
    }

    /// <summary>
    /// Gets a date mode.
    /// </summary>
    /// <param name="dateTime">
    /// The date to test.
    /// </param>
    /// <returns>
    /// A date mode.
    /// </returns>
    public TimeMode GetTimeMode(DateTime dateTime)
    {
        var timeSpan = DateTime.Now - dateTime;

        if (timeSpan < TimeSpan.FromSeconds(60)) return TimeMode.Seconds;
        if (timeSpan < TimeSpan.FromMinutes(60)) return TimeMode.Minutes;
        if (timeSpan < TimeSpan.FromHours(24)) return TimeMode.Hours;
        if (timeSpan <= TimeSpan.FromDays(30)) return TimeMode.Days; //this can be tricky for days in month, adapt as appropriate.
        if (timeSpan.Days <= 365) return TimeMode.Months; //adapt as apropriate for leap years.

        return TimeMode.Years;
    }

    /// <summary>
    /// Date Modes.
    /// </summary>
    public enum TimeMode
    {
        Seconds,
        Minutes,
        Hours,
        Days,
        Weeks,
        Months,
        Years
    }

tests with the following

MessageBox.Show(GetRelativeTime(DateTime.Now.Subtract(new TimeSpan(0, 0, 0, 20)))); //20 seconds ago
        MessageBox.Show(GetRelativeTime(DateTime.Now.Subtract(new TimeSpan(0, 0, 20, 0)))); //20 minutes ago
        MessageBox.Show(GetRelativeTime(DateTime.Now.Subtract(new TimeSpan(0, 20, 0, 0)))); //20 hours ago
        MessageBox.Show(GetRelativeTime(DateTime.Now.Subtract(new TimeSpan(1, 0, 0, 0)))); //1 day ago
        MessageBox.Show(GetRelativeTime(DateTime.Now.Subtract(new TimeSpan(2, 0, 0, 0)))); //2 days ago

EDIT: added VB Code

Dim Storage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
    Dim directory As String = "./MyNote/SavedNotes/*.*"
    Dim filenames As String() = Storage.GetFileNames(directory)
    Dim dataSource As New List(Of SampleData)()
    For Each filename As String In filenames
        Dim ISF As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
        Dim FS As IsolatedStorageFileStream = ISF.OpenFile("MyNote/SavedNotes/" & filename, FileMode.Open, FileAccess.Read)
        Using SR As New StreamReader(FS)
            'Modified code
            Dim FTime As String = GetRelativeTime(Storage.GetCreationTime("MyNote/SavedNotes/" & filename))
            Dim DATESS As String = SR.ReadLine
            Dim ReadName As String = SR.ReadLine
            dataSource.Add(New SampleData() With {.FileNameX = filename, .Description = ReadName, .FileTime = FTime})
        End Using
        SavedNotesList.ItemsSource = dataSource
    Next

'New Code

''' <summary>
''' Get's a date description
''' </summary>
''' <param name="dateTime">
''' The date to compare
''' </param>
''' <returns>
''' A date description.
''' </returns>
Public Function GetRelativeTime(dateTime As DateTime) As String
Dim myTimeMode = GetTimeMode(dateTime)

Select Case myTimeMode
    Case TimeMode.Seconds, TimeMode.Minutes, TimeMode.Hours
        Return dateTime.ToString("HH:mm")
    Case Else
        Return dateTime.ToString("dd/MM")
End Select
End Function

''' <summary>
''' Gets a date mode.
''' </summary>
''' <param name="dateTime">
''' The date to test.
''' </param>
''' <returns>
''' A date mode.
''' </returns>
Public Function GetTimeMode(timeToTest As DateTime) As TimeMode
Dim timeDifference = DateTime.Now - timeToTest

If timeDifference < TimeSpan.FromSeconds(60) Then
    Return TimeMode.Seconds
End If
If timeDifference < TimeSpan.FromMinutes(60) Then
    Return TimeMode.Minutes
End If
If timeDifference < TimeSpan.FromHours(24) Then
    Return TimeMode.Hours
End If
If timeDifference <= TimeSpan.FromDays(30) Then
    Return TimeMode.Days
End If
'this can be tricky for days in month, adapt as appropriate.
If timeDifference.Days <= 365 Then
    Return TimeMode.Months
End If
'adapt as apropriate for leap years.
Return TimeMode.Years
End Function

''' <summary>
''' Date Modes.
''' </summary>
Public Enum TimeMode
Seconds
Minutes
Hours
Days
Weeks
Months
Years
End Enum