工作心得分享

1. 心得分享
李佳駿

2. 委派 delegate
使用時機：可能會碰到某個方法在執行時需要
額外的處理，但你不想／無法將這部份的處理
寫死在類別裡（因為變化太多或無法預先得知
其處理規則）

3. 委派 delegate-1
 void Main()
 {
 CarMileage(10,0).Dump();
 }
 public int CarMileage(int time , int cartype)
 {
 switch (cartype)
 {
 case 0:
 return 10 * time;
 case 1:
 return 20 * time;
 default :
 return 30 * time;
 }
 }


4. 委派 delegate-2
 void Main()
 {
 CarMileage Mileage = new CarMileage(Car0);
 Mileage(10).Dump();
 }
 public delegate int CarMileage(int time);
 public int Car0(int time)
 {
 return 10 * time;
 }
 public int Car1(int time)
 {
 return 20 * time ;
 }
 public int CarOther(int time)
 {
 return 30 * time ;
 }

5. Using()
一些物件在執行完成後需要做 Dispose();
釋放記憶體 ，避免程式撰寫時會遺漏可以利用
 using (ZipArchive archive =
 new ZipArchive(zipToOpen, ZipArchiveMode.Update))
 {
 // 要做的事情
 }

6. ZipFile.OpenRead(zipPath)
number of entries expected in end of central
directory does not correspond to number of entries
in central directory
NuGet :DotNetZip

7. IEnumerable<T>
判斷有無資料請用
 if (resultItem.Count() > 0)
 if (resultItem.Any())

8. 取得 XML 資料
1. doc.Elements("cn-publication).
Element("document-id").Value;
1. doc.Descendants().Where(u => u.Name
== "country").First().Value;

9. SQL 隱碼攻擊
 using (SqlConnection conn = new SqlConnection(connstr))
 {
 conn.Open();
 StringBuilder sqlStr = new StringBuilder(
 @"Select * from [Table] where ID =“ + textBox1.Text );
 cmd.ExecuteNonQuery();
 }

10. SQL 隱碼攻擊 -1
 using (SqlConnection conn = new SqlConnection(connstr))
 {
 conn.Open();
 StringBuilder sqlStr = new StringBuilder(
 @"Select * from [Table] where ID=@ID“);
 SqlCommand cmd = new SqlCommand(sqlStr.ToString(), conn);
 cmd.Parameters.Add(new SqlParameter("@ ID ", textBox.Text));
 cmd.ExecuteNonQuery();
 }

11. .txt 比對資料 -1
比對字串裡面是否有“ 123” 這個字串
string sentence = File.ReadAllText(@"D:log.txt");
var isContain =
sentence.IndexOf("123",
StringComparison.OrdinalIgnoreCase) >= 0;


12. .txt 比對資料 -2
string[] contents = File.ReadAllLines(@“D:Log.txt");
return contents.Any(a => a == “123” );
return contents.All(a => a == “123”);
contents.Where( a=> a.Contains(“123"));

13. LINQ
命名習慣
在 LINQ 文件中，儲存查詢的變數的名稱中都會包含

“query” 這個字； 如果是儲存實際結果的變數，
它們的名稱中就不會有 “ query” 這個字。
var queryCities =
 from city in cities
 where city.Population > 100000
 select city;

14. LINQ-group
 var studentQuery2 =
 from student in students group student by student.Last[0]
 into g orderby g.Key select g;

15. BCP-1
 bcp "SELECT * FROM [table]”
 queryout %CD%FileName.data
 -U username -P password -S server -N
 -N ：當您要傳送的資料包含 ANSI 擴充字元而且您要利用原
生模式的效能時，請使用這個選項。

16. BCP-2
 bcp [DataBase].dbo.[Table]
 in %CD%FileName.data
 -U username -P password -S server –N

17. JavaScript-parseInt()
 >parseInt("123", 10)
 123

 >parseInt("010", 10)
 10
 > parseInt("010")
 8
 > parseInt("hello", 10)
 NaN
 > isNaN(NaN)

18. JavaScript-Boolean()
 false 、 0 、空字串 ("") 、 NaN 、 null 、以及 undefined 都
會成為 false
 > Boolean(234)
 true

19. JavaScript-arguments
 function add() {
 var sum = 0;
 for (var i = 0, j = arguments.length; i < j; i++)
 {
• sum += arguments[i];
 }
 return sum;
 }
 > add(2, 3, 4, 5)
 14
 > add(2, 3, 4)
 9
 arguments.callee.count

20. Jquery
 http://www.w3school.com.cn/tags/att_a_hreflang.asp
 HTML 標籤
 http://jsbin.com/fayidowuce/5/edit
 jsbin

21. Jquery
 <div class="OK"></div>
 $( ".OK" )
 <div id ="OK"></div>
 $( "#OK" )
 <div></div>
 $( "div" )
 <div class="after-andself">
 <p>First Paragraph</p>
 <p>Second Paragraph</p>
 </div>
 $( "div.before-andself" )

22. Jquery
 <div class="left"></div>
 <div class="right"></div>
 $( "div.left, div.right" )

23. SQL 隱碼攻擊 -1
 http://huan-lin.blogspot.com/2009/01/delegate-revisited-csharp-1-to-2-to-3.html 委派
 http://www.dotblogs.com.tw/smartleos/archive/2013/04/10/101297.aspx
 IEnumerable<T> 中有無資料，用 Any()