目前分類：C# 技術文章 (22)
- Nov 29 Thu 2012 17:37
[C#] HTML Agility Pack 相關
- Nov 19 Mon 2012 18:40
[C#] Convert Json to C# DataStruct by JSON.NET library
JSON.NET Sample
JSON deserialization with JSON.net
To help user to auto-convert json to c# data structure.
json2csharp
download json.net lib and document.
json.net library
- Oct 11 Thu 2012 18:05
C# 與 ReportingService2005 互動的方法
Step1：開啟一個專案(EX: console application)
Step2：如下圖操作(點選 Reference)，選取 Add Web Service，會跳出一個視窗。該視窗是WCF設定視窗，不過我們需要用的是舊型的Web Service，所以點選左下角的按鈕(Advance)。
Step3: 繼續往舊版的Web Service設定前進(點選下方的按鈕)
- Sep 17 Mon 2012 18:42
[C#] C# 讀取 Excel file 相關資料
Tutorial
http://csharp.net-informations.com/excel/csharp-excel-tutorial.htm
The Simple method of use
http://www.dotblogs.com.tw/yc421206/archive/2009/01/11/6727.aspx
- Jul 13 Fri 2012 00:25
[C#] ref 關鍵字利用在 object上的效果。
睡前翻書翻到的。然後上msdn發現...嘿嘿，竟然沒講。
http://msdn.microsoft.com/zh-tw/library/14akc2c7(v=vs.100).aspx
這有點難用程式碼寫出來，不過我覺得應該用個...一些圖表示，有空在畫好了。
// 預備畫圖...
這個關鍵字簡單來說就跟pointer概念上是一樣的，但是.....在C#裡面，假設你是用Object的話，他本身在傳遞上就是Call by reference。
- Jun 27 Wed 2012 00:21
[C#] C# 4.0：Named and Optional Arguments
http://msdn.microsoft.com/en-us/library/dd264739.aspx
msdn的說明。
先講 Optional Arguments(可選參數)應用在Method(方法)上，這功能就是幫你預設好參數(Arguments)值，當有輸入值的時候就聽遵循輸入值的話 ; 當沒有輸入值的時候就直接把預測值塞入。 這東西可以用Overload的寫法實作，但是程式碼將會壟長很多..。
(程式碼實作比較：Optional Arguments vs overload 寫法)
- Jun 19 Tue 2012 20:00
[C#] .Net 4.0 新功能 ZIP!!!
當初是為了處理兩個Array / List 放在同一個For loop內一起使用，但是不想要改動到既有的程式碼而上網查的。(簡單來說本來功能都寫好了，但是我臨時發現忘記記錄一筆資料，但我List 的 Data struct都設計好了不想再更動他，所以想想有沒有比較偷懶的方法)
.Net 4.0推出這個東西其實還蠻不錯的.....雖然當下看會覺得這個Func真的是一點屁用都沒有，因為一般人不會那麼蠢把都要放到For loop中的資料拆成兩個Array。
不過站在這種奇妙的案例下這Func就蠻有用的...= =++
http://stackoverflow.com/questions/4450650/using-foreach-loop-to-iterate-through-two-lists
- Jun 15 Fri 2012 15:10
[C#] 比較兩個 List<int> 是否相同的方法
- Jun 14 Thu 2012 18:29
[C#] 實現Singleton的方法比較
- Jun 12 Tue 2012 15:57
[C#] "Where" of LINQ (three methods)
- Apr 15 Sun 2012 16:38
[C#] "Where" of LINQ (three methods)
// Main function
class MainFunc
{
static void Main(string[] args)
{
string[] animals = new string[] { "Koala", "Spider", "Elephant" };
wherepractice prac = new wherepractice();
// get animals of StartName is "S"
prac.detailWhere(animals);
// get amimals of StartName is "E"
prac.lambdaWhere(animals);
// as above result, but different implement.
prac.delegateImpleWhere(animals);
Console.ReadLine();
return;
}
}
// subClass
public void detailWhere(string[] animals)
{
var q = from a in animals
where a.StartsWith("S")
select a;
foreach (string s in q)
{
printString(s);
}
}
public void lambdaWhere(string[] animals)
{
var q = animals.Where(a => a.StartsWith("E"));
foreach (string s in q)
{
printString(s);
}
}
public void delegateImpleWhere(string[] animals)
{
// To utilize "delegate" to implement lambda expression "Where".
var q = animals.Where(
delegate(string a){return a.StartsWith("E");}
);
foreach (string s in q)
{
printString(s);
}
}
- Apr 15 Sun 2012 16:30
[C#] goto statement
This is a simple sample for Exit statement.
static void Main(string[] args)
{
Program.correctGoto();
Program.GotoInfiniteLoop();
Program.falseGoto();
}
//This is a correct Goto statement method.
static public void correctGoto()
{
for (int i = 0; i < 100; i++)
{
Console.WriteLine("{0}", i);
if (i == 5)
{
goto Exit;
}
}
Exit: Console.WriteLine("Exit");
}
//If you put Exit tag before goto statement, it will cause infinite loop.p>
static public void GotoInfiniteLoop()
{
Exit: Console.WriteLine("Exit");
for (int i = 0; i < 100; i++)
{
Console.WriteLine("{0}", i);
if (i == 7)
{
goto Exit;
}
}
}
//It's a wrong method to use exit statement.
static public void falseGoto()
{
for (int i = 0; i < 100; i++)
{
Console.WriteLine("{0}", i);
if (i == 7)
{
Exit: Console.WriteLine("Exit");
}
// this method can't jump from external into internal.
goto Exit;
}
}
- Apr 12 Thu 2012 14:09
[C#] "Where" of LINQ (three methods)
// Main function
class MainFunc
{
static void Main(string[] args)
{
string[] animals = new string[] { "Koala", "Spider", "Elephant" };
wherepractice prac = new wherepractice();
// get animals of StartName is "S"
prac.detailWhere(animals);
// get amimals of StartName is "E"
prac.lambdaWhere(animals);
// as above result, but different implement.
prac.delegateImpleWhere(animals);
Console.ReadLine();
return;
}
}
// subClass
public void detailWhere(string[] animals)
{
var q = from a in animals
where a.StartsWith("S")
select a;
foreach (string s in q)
{
printString(s);
}
}
public void lambdaWhere(string[] animals)
{
var q = animals.Where(a => a.StartsWith("E"));
foreach (string s in q)
{
printString(s);
}
}
public void delegateImpleWhere(string[] animals)
{
// To utilize "delegate" to implement lambda expression "Where".
var q = animals.Where(
delegate(string a){return a.StartsWith("E");}
);
foreach (string s in q)
{
printString(s);
}
}
- Apr 10 Tue 2012 20:14
[C#] List Initialization between 2.0 and 3.0
class ListInit
{
static void Main(string[] args)
{
// The demo of List Initialize Set including old declaration and new declaration(C#3.0)
// Old initialization.
List stringOld = new List();
stringOld.Add("string_1");
stringOld.Add("string_2");
// New initialization.
List stringNew = new List()
{
"string_1",
"string_2"
};
// Combine Object and List Init.
List list = new List{
new Contact{
LastName = "Alen",
DateOfBirth = new DateTime(1234,1,13)
},
new Contact{
LastName = "AlenTwo",
DateOfBirth = new DateTime(2345,1,23)
}
};
}
private class Contact
{
public string LastName { get; set; }
public DateTime DateOfBirth { get; set; }
}
}
- Apr 06 Fri 2012 13:40
[C#] Object Initialization between 2.0 and 3.0
class Program
{
static void Main(string[] args)
{
// The demo of Object Initialize Set including old declaration and new declaration(C#3.0)
// If member access modifier isn't declared as "public", method_1 and method_2 isn't working.
// method_1
Contact contact = new Contact();
contact.LastName = "A-len";
contact.DateOfBirth = new DateTime(2012, 04, 03);
//method_2
Contact contactNew = new Contact
{
LastName = "A-len",
DateOfBirth = new DateTime(2012, 04, 03)
};
}
private class Contact
{
public string LastName { get; set; }
public DateTime DateOfBirth { get; set; }
}
}
- Jan 19 Thu 2012 00:19
[C#]How to adjust the encoding in StreamReader
StreamReader defaults to UTF-8 encoding unless specified otherwise, instead
of defaulting to the ANSI code page for the current system.
(Hint: Convert xls/xlsx file to csv file. the encoding is ANSI.)
http://msdn.microsoft.com/zh-tw/library/6aetdk20(v=vs.100).aspx
- Jan 15 Sun 2012 22:35
[C# 3.0] Type Parameter Assumption
Main Function
namespace ConsoleGenericsAssumption
{
class Program
{
static void Main(string[] args)
{
GenericTypeResolverTest v = new GenericTypeResolverTest("Hello Alam");
//v.Value = "Hello ALam";
v.ShowInConsole();
// -----same result, differnet implementation---
Console.WriteLine("-----same result, differnet implementation---");
string showString = v.ToString();
Console.WriteLine("{0}", showString);
Console.ReadLine();
// generic for string
string ValueString = "Hello Yaya";
ValueString.ShowInConsole();
// generic for int
int ValueInt = 12345;
ValueInt.ShowInConsole();
}
}
}
Another class
public class GenericTypeResolverTest
{
public string Value { get; set; }
public GenericTypeResolverTest() { }
public GenericTypeResolverTest(string value)
{
Value = value;
}
public override string ToString()
{
return Value.ToString();
}
}
public static class GenericTypeResolverMethodTest
{
public static void ShowInConsole(this T obj)
{
Console.WriteLine(obj.ToString());
Console.ReadLine();
}
}
- Jan 09 Mon 2012 00:54
[C#] What's different of [], List and ArrayList.
static void Main(string[] args)
{
// [] is specific type and fixed length.
// It is a data structure.
String[] arr = new string[] {"Hi", "I", "am", "ALam"};
ShowMessage(arr);
// List is specific type and unbounded length.
// namespace is System.Collection.Generic
List list = new List();
list.Add("Hi");
list.Add("I");
list.Add("am");
list.Add("Alam");
ShowMessage(list);
// ArrayList is any type and undounded length.
// namespace is System.Collection
ArrayList arraylist = new ArrayList();
arraylist.Add("Hi");
arraylist.Add("I");
arraylist.Add("am");
arraylist.Add("Alam");
arraylist.Add(12345); // when we call the ShowMessage, it will be wrong.
ShowMessage(arraylist);
}
private static void ShowMessage(string[] temp)
{
foreach (string aaa in temp)
{
Console.WriteLine("{0}", aaa);
}
Console.ReadLine();
}
private static void ShowMessage(List temp)
{
foreach (string aaa in temp)
{
Console.WriteLine("{0}", aaa);
}
Console.ReadLine();
}
private static void ShowMessage(ArrayList temp)
{
foreach (string aaa in temp)
{
Console.WriteLine("{0}", aaa);
}
Console.ReadLine();
}
}
- Jan 08 Sun 2012 23:29
[C#] access stored procedure by linq
// to associates a stored procedure which user defined in the database.
// Must write it before func.
[global::System.Data.Linq.Mapping.FunctionAttribute(Name ="stored procedure name")]
// Undertake on a code, we make a func. let user to access the stored procedure.
// When SP exist input variables, you must use "Linq.Mapping.ParameterAttribute" to
// select the variable in DB and use "System.Nullable" to set
// what variable you wnat to assign in code.
public int storedProcedureForC#Class(
[global::System.Data.Linq.Mapping.ParameterAttribute(Name:"inputVarName",
DbType="inputVarType"] System.Nullable varInC#)
{
// Execute the stored procedure.
IExecuteResult objectForSP = this.ExecuteMethodCall(this, (
(MethodInfo)(MethodInfo.GetCurrentMethod())), varInC#);
return ((int)(result.ReturnValue));
}
- Jan 04 Wed 2012 22:55
[C#] Specific Symbol"as" is used in Session of asp.net
So........We know "as" is a powerful method that perform certain types of conversions between compatible reference types. for example:
// ...... // Array[] = dataTable; // ....do something for dataTable.// const string = "ALamTest"; Session[ALamTest] = dataTable; //....do another something...// Array[] getTable = Session[AlamTest] as Array[]
When we use Session Mechanism, "as" is a useful method let us to redesign the object which is taken out from the session.
