prague12

Imports System.Threading
Imports System.Threading.Tasks
Imports System.Drawing
'要專案 參考 System.Drawing.dll

'------------
'平行 foreach 使用方法
'------------

Module Module1 'VB2010 主控台程式

Sub Main()

' A simple source for demonstration purposes. Modify this path as necessary.
Dim files As String() = System.IO.Directory.GetFiles("C:\11", "*.jpg") '從C:\11 資料夾 找副檔名.jpg 的圖
Dim newDir As String = "C:\JK" '在 C:\ 產生JK目錄
System.IO.Directory.CreateDirectory(newDir)
' Method signature: Parallel.ForEach(IEnumerable source, Action body)
' Be sure to add a reference to System.Drawing.dll.
Parallel.ForEach(files, Sub(mm)
'上一行不能有註解 會破壞語法


' The more computational work you do here, the greater
' the speedup compared to a sequential foreach loop.
Dim filename As String = System.IO.Path.GetFileName(mm)
Dim bitmap As New System.Drawing.Bitmap(mm)

bitmap.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone) '抓一張圖來旋轉180度
bitmap.Save(System.IO.Path.Combine(newDir, filename)) '把轉後的圖存在新目錄底下

' Peek behind the scenes to see how work is parallelized.
' But be aware: Thread contention for the Console slows down parallel loops!!!

Console.WriteLine("Processing {0} on thread {1}", filename, Thread.CurrentThread.ManagedThreadId)
'close lambda expression and method invocation
End Sub)

' Keep the console window open in debug mode.
Console.WriteLine("Processing complete. Press any key to exit.")
Console.ReadKey() '讀取任意鍵入字元後結束


End Sub

End Module