{"id":303,"date":"2009-04-10T17:02:00","date_gmt":"2009-04-10T09:02:00","guid":{"rendered":""},"modified":"2013-11-17T13:02:09","modified_gmt":"2013-11-17T05:02:09","slug":"c%e5%ad%a6%e4%b9%a0%e7%ac%94%e8%ae%b0%e4%b8%80","status":"publish","type":"post","link":"https:\/\/kyle.ai\/blog\/303.html","title":{"rendered":"C#\u5b66\u4e60\u7b14\u8bb0[\u4e00]"},"content":{"rendered":"

C#\u7a97\u53e3\u5e94\u7528\u5982\u4f55\u5c45\u4e2d:\u5728form\u7684\u5c5e\u6027\u8bbe\u7f6e\u91cc\u9762\u6709\u4e00\u4e2a\u521d\u59cb\u4f4d\u7f6e\u7684\u8bbe\u7f6e\uff08startposion\uff09 \u8bbe\u7f6e\u6210centerscreen\uff08\u5c4f\u5e55\u5c45\u4e2d\u5373\u53ef\uff09<\/p>\n

\n

1\u3001\u8bfb\u53d6\u524dN\u6761\u6307\u5b9a\u7684\u8bb0\u5f55<\/p>\n

select top N from \u8868 where …… order by ….<\/p>\n

2\u3001\u8bfb\u53d6\u6700\u540eN\u6761\u6307\u5b9a\u7684\u8bb0\u5f55(\u5047\u8bbe\u603b\u8bb0\u5f55\u6709M\u6761)<\/p>\n

select top N from \u8868 where id not in(select top M-N id from talbe)<\/p>\n

3\u3001\u968f\u673a\u8bfb\u53d6N\u6761\u8bb0\u5f55<\/p>\n

Sql server:\u00a0\u00a0 select top n * from \u8868 order by newid()<\/p>\n

Access:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Select top n * FROM \u8868 orDER BY Rnd(id)<\/p>\n

mysql:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Select * From \u8868 order By rand() Limit n<\/p>\n

Request.QueryString[“title”] \u9002\u7528\u4e8eGet\u65b9\u6cd5<\/p>\n

Request.Form[“title”] \u9002\u7528\u4e8ePost\u65b9\u6cd5<\/p>\n

\r\nprotected void Page_Load(object sender, EventArgs e)\r\n    {\r\n        if (!IsPostBack)\r\n        {\r\n            GetDB();\r\n        }\r\n    }\r\n    public void GetDB()\r\n    {\r\n        string strsql = "Data Source=localhost;Initial Catalog=News;Persist Security Info=True;User ID=sa;Password=hacklzt";\r\n        SqlConnection conn = new SqlConnection(strsql);\r\n        try\r\n        {\r\n            conn.Open();\r\n            string strquery = "select * from NewsInfo";\r\n            SqlCommand cmd = new SqlCommand(strquery, conn);\r\n            SqlDataReader reader = cmd.ExecuteReader();\r\n            while (reader.Read())\r\n            {\r\n                Response.Write(reader["NewsTitle"]);\r\n            }\r\n        }\r\n        catch (Exception ee)\r\n        {\r\n            Response.Write(ee.ToString());\r\n        }\r\n    }\r\n      protected void Button3_Click(object sender, EventArgs e)\r\n      {\r\n          if (FileUpload1.PostedFile != null)\r\n          {\r\n              Boolean fileok=false;\r\n              string name = FileUpload1.PostedFile.FileName;\r\n              int i = name.LastIndexOf(".");\/\/\u53d6\u6700\u540e\u4e00\u4e2a.\u5728\u540d\u5b57\u91cc\u9762\u7684\u4f4d\u7f6e\r\n              string newtext = name.Substring(i,name.Length-i); \/\/\u53d6\u540e\u7f00\u540d\r\n              System.DateTime now = System.DateTime.Now;\r\n              string newname = now.DayOfYear.ToString() + FileUpload1.PostedFile.ContentLength.ToString();\r\n              \/\/string newname = now.ToString();\r\n              if (FileUpload1.HasFile)\r\n              {\r\n                  string[] allowedextension = {".gif",".jpeg",".jpg",".rar",".txt"};\r\n                  for (int a=0;a<allowedextension.Length;a++)\r\n                  {\r\n                      if ((newtext == allowedextension[a])&&(FileUpload1.PostedFile.ContentLength<500000))\r\n                      {\r\n                          fileok = true;\r\n                      }\r\n                  }\r\n              }\r\n              if (fileok)\r\n              {\r\n                 try\r\n                 {\r\n                     FileUpload1.PostedFile.SaveAs(Server.MapPath("~\\\\upload\\\\" + newname + newtext));\r\n                     Label2.Text = "\u4e0a\u4f20\u6210\u529f";\r\n                 }\r\n                 catch\r\n                 {\r\n                     Label2.Text = "\u4e0a\u4f20\u5931\u8d25";\r\n                 } \r\n              }\r\n              else\r\n              {\r\n                  Label2.Text = "\u6587\u4ef6\u683c\u5f0f\u4e0d\u5bf9\u6216\u8005\u6587\u4ef6\u592a\u5927";\r\n              }\r\n          }                  \r\n      }\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
C#\u7a97\u53e3\u5e94\u7528\u5982\u4f55\u5c45\u4e2d:\u5728form\u7684\u5c5e\u6027\u8bbe\u7f6e\u91cc\u9762\u6709\u4e00\u4e2a\u521d\u59cb\u4f4d\u7f6e\u7684\u8bbe\u7f6e\uff08startposion\uff09 \u8bbe\u7f6e\u6210cente […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-303","post","type-post","status-publish","format-standard","hentry","category-code_related"],"_links":{"self":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/303","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/comments?post=303"}],"version-history":[{"count":2,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions"}],"predecessor-version":[{"id":4615,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions\/4615"}],"wp:attachment":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/media?parent=303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/categories?post=303"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/tags?post=303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}