順序按日期txt文件用vb.net

Question

我犯了一個程序，它從IMDB API的發佈日期和標題和.txt文件保存他們他們...我可以按日期莫名其妙

責令其

Imports System.IO 
Imports System.Xml.Linq 
Imports System.Text.RegularExpressions 

Public Class Form1 

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click 

     Dim _reg As Regex = New Regex("http://www.imdb.com/title/([A-Za-z0-9\-]+)/*?", _ 
       RegexOptions.IgnoreCase) 

     Dim value As String = TextBox1.Text 

     Dim m As Match = _reg.Match(value) 

     If (m.Success) Then 
      Dim key As String = m.Groups(1).Value 
      Dim url As String = "http://mymovieapi.com/?id=" + key + "&type=xml&plot=none&episode=0&lang=en-US&aka=simple&release=simple&business=0&tech=0" 
      Dim Document As XDocument = XDocument.Load(url) 
      Dim title = Document.Root.Element("title").Value() 
      Dim releaseDate = Date.ParseExact(Document.Root.Element("release_date").Value, 
        "yyyyMMdd", System.Globalization.CultureInfo.InstalledUICulture) 
      TextBox2.Text = "Release Date: " & releaseDate & "/ Title: " & title 
     Else : TextBox2.Text = "Please use IMDB links" 
     End If 
     Button2.Enabled = True 
    End Sub 


    Private Sub Button2_Click_1(sender As System.Object, e As System.EventArgs) Handles Button2.Click 
     Dim Writer As System.IO.StreamWriter 
     Writer = New System.IO.StreamWriter("C:\Users\Azer\Documents\Movies.txt", True) 
     Writer.Write(TextBox2.Text & vbCrLf) 
     Writer.Close() 
     Button2.Enabled = False 
    End Sub 

    Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click 
     Dim Reader As System.IO.StreamReader 
     Reader = New System.IO.StreamReader("C:\Users\Azer\Documents\Movies.txt") 
     Dim tempstring As String 
     Do 
      tempstring = Reader.ReadLine() 
      TextBox3.Text = TextBox3.Text + tempstring + vbCrLf 
     Loop Until tempstring = "" 
     Reader.Close() 
    End Sub 

    Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click 
     Me.Close() 
    End Sub 

    Private Sub Button5_Click(sender As System.Object, e As System.EventArgs) Handles Button5.Click 
     TextBox3.Clear() 
    End Sub 
End Class 

Answer 1

正如大衛所說，數據庫會使這容易得多。但是，如果你不能使用數據庫（或者有其他理由這樣做），這裏有一種方法來處理它。

使保存的信息小班（使其更容易進行排序，像這樣：

Public Class MovieInfo 

    Public Property As DateTime 
    Public Title As String 
End Class 

接下來，讀取當前文件（如果存在）和填充在它的數據List<MovieInfo> 。

Dim movies As String() = File.ReadAllLines("C:\Users\Azer\Documents\Movies.txt") 

Dim movieParts = From m in movies 
       Select m.Split(New String() { "/", ":" }, StringSplitOptions.RemoveEmptyEntries) 

Dim parsedDate As DateTime 

Dim movieData As List(Of MovieInfo) = (From mi In movieParts 
             Select New MovieInfo With 
             { 
              .ReleaseDate = _ 
     If(DateTime.TryParseExact(mi(1).Trim, "dd.MM.yyyy", _ 
     System.Globalization.CultureInfo.InvariantCulture, _ 
     System.Globalization.DateTimStyle.None, _ 
     parsedDate), parsedDate, DateTime.MinValue), 
              .Title = mi(3).Trim() 
             }.ToList() 

本質上面的代碼讀取文本文件轉換成一個陣列（每個元素一行），然後使用LINQ將每個線分成4份基於：和/那麼它需要該查詢的結果。並生成一個MovieInfo列表，並將日期字符串轉換爲Dat易於分類的eTime。

DateTime.TryParseExact接收指定格式的輸入字符串（在本例中爲dd.MM.yyyy），並在可能的情況下將其轉換爲DateTime對象。如果成功，則返回true，DateTime值位於parsedDate變量中。如果不是這樣，我使用DateTime的MinValue作爲MovieInfo類的ReleaseDate屬性。

之後，您將從API調用中獲取新數據並將其添加到MovieInfo列表中（您可能希望消除任何重複項）。由於您沒有發佈API中的數據格式，因此我很難給您一個代碼樣本來解析它，但簡而言之，您可以構建第二個MovieInfo對象列表，然後合併現有和新的一起列出。

然後您排序MovieInfo列表並覆蓋原始文本文件。這樣的事情應該做的伎倆：

movieData.Sort(Function(x, y) y.ReleaseDate.CompareTo(x.ReleaseDate)) 

Dim output As New StringBuilder() 

For Each info As MovieInfo in movieData 
    output.Append("Release Date: ") 
    output.Append(info.ReleaseDate.ToString("dd.MM.yyyy")) 
    output.Append("/Title: ") 
    output.Append(info.Title) 
    output.Append(Enviroment.NewLine) 
Next 

File.WriteAllText("C:\Users\Azer\Documents\Movies.txt", output.ToString()) 

此代碼對列表進行排序與​​lambda表達式把日期順序電影（最新到最舊）。然後使用帶有For Each循環的StringBuilder構建輸出，然後將其寫入文件（如果文件已存在，則覆蓋該文件）。

請注意，如果您在排序中反轉x和y，則會按日期變得最早到最新。