Eric Tsai: Microsoft Visual Studio

WaitHandle.WaitAll無法處理長度超過64的陣列

Mon, 12 May 2008 17:41:21 GMT

當有一些大量計算可以multi-thread同時做的時候我喜歡用ThreadPool.QueueUserWorkItem丟下去跑。無論是用ThreadPool或多個Thread，有時需要等待那些計算全部完成才能繼續做後續動作，這時就可以用一個ManualResetEvent的collection搭配WaitHandle.WaitAll。然而WaitHandle.WaitAll在陣列元素超過64個的時候就會發生NotSupportedException。

還好WaitHandle.WaitAll做的事情其實很簡單，我們可以自己寫一個function來做。以下是一位C# MVP William Stacey提供的一段WaitAll程式碼：

        public static void WaitAll(WaitHandle[] handles)
        {
            if (handles == null)
                throw new ArgumentNullException("handles");
            foreach (WaitHandle wh in handles)
            {
                wh.WaitOne();
            }
        }

ASP.NET AJAX 循序執行

Thu, 01 May 2008 17:29:12 GMT

ASP.NET AJAX預設如果在前一個動作還沒做完時就引發第二個動作，會把前一個動作直接中斷並執行第二個，造成程式碼常常會有一些奇怪的錯誤。網路上有人把它改寫成把動作放到queue中，依序執行。

只要在aspx中引用下面文章中提供的PageRequestManagerEx.js並呼叫PageRequestManagerEx.init()即可。

Asp.net Ajax UpdatePanel Simultaneous Update - A Remedy

放在 UpdatePanel 中的 TreeView 效能很差

Thu, 01 May 2008 17:13:04 GMT

最近需要用到好幾MB的TreeView，展開時要自動更新TreeNode內容，結果在展開時慢到IE都會跳出來問我要不要中止script的執行。在網路上努力的找了一下資料，運氣不錯發現不久之前剛好有人提到原來要把TreeView的EnableClientScript屬性設為false。不過我後來還是更進一步把ChildNodes改成動態產生，減低所佔的空間就是了......

Very slow TreeView in UpdatePanel

順道一提，IE是以不是以時間判斷script執行時間過久，而是以執行了多少個statement來計算。如果要修改預設的statement數量限制可參考：How to set time-out period for script

How to choose between arrays and collections

Thu, 09 Nov 2006 03:17:14 GMT

Cited from Performance Best Practices at a Glance

Arrays are the fastest of all collection types, so unless you need special functionalities like dynamic extension of the collection, sorting, and searching, you should use arrays. If you need a collection type, choose the most appropriate type based on your functionality requirements to avoid performance penalties.

Use ArrayList to store custom object types and particularly when the data changes frequently and you perform frequent insert and delete operations. Avoid using ArrayList for storing strings.
Use a StringCollection to store strings.
Use a Hashtable to store a large number of records and to store data that may or may not change frequently. Use Hashtable for frequently queried data such as product catalogs where a product ID is the key.
Use a HybridDictionary to store frequently queried data when you expect the number of records to be low most of the time with occasional increases in size.
Use a ListDictionary to store small amounts of data (fewer than 10 items).
Use a NameValueCollection to store strings of key-value pairs in a presorted order. Use this type for data that changes frequently where you need to insert and delete items regularly and where you need to cache items for fast retrieval.
Use a Queue when you need to access data sequentially (first in is first out) based on priority.
Use a Stack in scenarios where you need to process items in a last–in, first-out manner.
Use a SortedList for fast object retrieval using an index or key. However, avoid using a SortedList for large data changes because the cost of inserting the large amount of data is high. For large data changes, use an ArrayList and then sort it by calling the Sort method.

Visual C++ 2005 Express Edition Installation

Thu, 05 Oct 2006 09:02:55 GMT

Visual Studio 2005 & 2008 Express Editions (Traditional Chinese) ISO Images

Sat, 15 Jul 2006 20:49:27 GMT

VB 2005 Express ISO:
http://download.microsoft.com/download/6/e/1/6e1e8e73-6e42-4790-a23e-4f3f3a8b776b/VB.ISO

VC# 2005 Express ISO:
http://download.microsoft.com/download/d/6/5/d655c429-1d43-43d1-84c2-18acee6c0925/VCS.ISO

VWD 2005 Expess ISO:
http://download.microsoft.com/download/4/1/b/41bb5e6a-b72b-4994-aac5-9a15aa115929/VWD.ISO

VC 2005 Express ISO:
http://download.microsoft.com/download/d/a/3/da39d165-bfc5-4323-8230-0caf8ed7d7c3/VC.ISO

Visual Studio 2005 Express Editions Service Pack 1

http://www.microsoft.com/downloads/details.aspx?familyid=7b0b0339-613a-46e6-ab4d-080d4d4a8c4e

Visual Studio 2008 Express Edition ISO:

http://download.microsoft.com/download/4/D/8/4D872F14-298B-4715-8741-0BAD3915EF45/VS2008ExpressCHTX1428503.iso

用 window.showModalDialog 開出來的視窗 PostBack 時會開啟新視窗

Sat, 15 Jul 2006 20:14:15 GMT

在html的head中加上<base target="_self">即可解決。

MaxLength of TextBox in GridView Edit Mode

Sat, 15 Jul 2006 20:12:45 GMT

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    foreach (Control c in e.Row.Cells[1].Controls)
    {
        if (c is TextBox)
        {
            ((TextBox)c).MaxLength = 6;
        }
    }
}

Make Global.asax Code-Behind in ASP.NET 2.0

Sat, 15 Jul 2006 20:11:45 GMT

http://dallas.sark.com/SarkBlog/cboland/archive/2005/11/14/2234.aspx

讓 IE 不在圖片上顯示圖片工具列

Sat, 15 Jul 2006 20:08:02 GMT

About My Pictures Photo Support

刪除已載入到PictureBox的檔案

Sat, 15 Jul 2006 19:30:24 GMT

先pictureBox1.Image.Dispose();
然後pictureBox1.Image=null;
最後就可以砍檔了～

要不然會因為檔案還在使用中而無法刪除...