<address id="xpjh9"><listing id="xpjh9"><meter id="xpjh9"></meter></listing></address>

<address id="xpjh9"><address id="xpjh9"><listing id="xpjh9"></listing></address></address>
<noframes id="xpjh9">
<noframes id="xpjh9">

<address id="xpjh9"><address id="xpjh9"><listing id="xpjh9"></listing></address></address>
    <form id="xpjh9"></form><address id="xpjh9"><listing id="xpjh9"><menuitem id="xpjh9"></menuitem></listing></address>

      <noframes id="xpjh9">
      VB.net 2010 視頻教程 VB.net 2010 視頻教程 VB.net 2010 視頻教程
      SQL Server 2008 視頻教程 c#入門經典教程 Visual Basic從門到精通視頻教程
      當前位置:
      首頁 > 編程開發 > vb >
      • vb教程之VB5.0中實現系統登錄

      • 2017-09-21 16:27 來源:未知
      ---- 一般進入系統都要登錄(如進入Windows NT),進行身份檢驗,以保證軟件的合法使用和維護,便于明確責任。我們自己開發的系統也必須保證系統使用者是合法用戶,登錄時要進行身份驗證。 

      ---- 系統登錄時一般有三次機會,超過則視為非法用戶,不讓使用系統。本程序是用VB5.0實現的,后臺數據庫是Access 97。 

      其主要源程序代碼如下: 
      Private Sub cmd_yes_Click() 
      '開始檢驗 
      Picture1.Picture = LoadPicture("trffc10b.ico") 
      times = times + 1 
      '解密 
      txt_mm.Text = invert(txt_mm.Text) 
      '查找用戶名 
      ordc_dlmmk.Recordset.FindFirst 
      "username='" & txt_bh.Text & "'" 
      If ordc_dlmmk.Recordset.NoMatch Then 
      If times < 3 Then 
      Picture1.Picture = LoadPicture("trffc10c.ico") 
      MsgBox "無此用戶,請重新輸入!", 
      vbExclamation + vbOKOnly,"提示信息" 
      Picture1.Picture = LoadPicture("trffc09.ico") 
      txt_bh.SetFocus 
      Call txt_bh_GotFocus 
      Exit Sub 
      Else 
      MsgBox "對不起,您無權使用本系統 
      ," + vbCrLf + vbCrLf + " 請與系統管理員聯系! ", 
      vbCritical + vbOKOnly, "提示信息" 
      End 
      End If 
      End If 
      If times < 3 Then 
      If Not (UCase(txt_mm.Text) 
      = UCase(Text2.Text)) Then 
      txt_mm.Text = invert(txt_mm.Text) 
      Picture1.Picture = LoadPicture("trffc10c.ico") 
      MsgBox "用戶密碼錯誤,請重新輸入!", 
      vbExclamation, "提示信息" 
      Picture1.Picture = LoadPicture("trffc09.ico") 
      txt_mm.SetFocus 
      Call txt_mm_GotFocus 
      Exit Sub 
      Else 
      Picture1.Picture = LoadPicture("trffc10a.ico") 
      MsgBox "歡迎您使用本系統!", vbInformation, "提示信息" 
      Unload Me 
      frm_welcome.Show 
      End If 
      ElseIf times = 3 Then 
      If UCase(txt_mm.Text) = UCase(Text2.Text) Then 
      Picture1.Picture = LoadPicture("trffc10a.ico") 
      MsgBox "歡迎您使用本系統!", vbInformation, "提示信息" 
      Unload Me 
      frm_welcome.Show 
      Exit Sub 
      End If 
      MsgBox "對不起,您無權使用本系統, 
      " + vbCrLf + vbCrLf + " 請與系統管理員聯系! ", 
      vbCritical + vbOKOnly, "提示信息" 
      End 
      End If 
      End Sub 

      ---- 由于一般系統用戶有多個,所以必須設置多用戶。通常用戶名和對應密碼以數據庫的形式保存。但數據庫極易暴露,可直接通過打開數據庫而獲取用戶名和密碼,安全性不好,所以應進行加密工作--保存在數據庫中的密碼與登錄時輸入的密碼不一樣,保存時進行加密,登錄時進行解密。這樣,即使看到了數據庫內容,如果不知道解密過程也無法進入系統。 

      ---- 一個比較簡單的加密過程如下: 

      Public Function invert(passw As String) 
      Dim i As Integer 
      Dim Temp As String 
      Temp = "" 
      For i = Len(passw) To 1 Step -1 
      Temp = Temp + Mid(passw, i, 1) 
      Next i 
      invert = Temp 
      End Function 

      ---- 至此一個簡單的系統登錄過程就實現了。
      相關教程
      江苏快3 www.5099jj.com | www.ab99900.com | 1434k.com | www.bw123123.com | ii2649.com | www.bwinyz17.com | 86611z.com | www.6126.com | www.6033x.com | www.595953.com | www.08159g.com | 26668l.com | www.89155444.com | 2jsfff.com | www.gczj2.com | www.2078p.com | js89t.vip | www.2y938.com | 77889193.com | www.4323f.com | 7792m.com | www.373170.com | www.999345.com | 5456.com | www.ya2019p.com | www.wn2048.com | www.209703.com | www.www-26499.com | xiaowei398.com | www.3a003.com | ii5443.com | www.713667.com | www.hg2381.com | 3846pp.com | www.xpj7707.com | 8290z.com | www.541711.com | www.599123.com | 88772105.com | www.12455n.com | www.515xpj.com | feicai0816.com | www.673888f.com | 25288n.com | www.901758.com | www.588112.com | 0805o.com | www.qucp5.com | www.xpj2718.com | 4812a.com | www.26299i.com | www.56520t.com | xpj677u.com | www.a98478.com | www.yddc00.com | yd12309.com | www.97828n.vip | www.hg8988.com | 6hcc88.com | www.44118c.com | y33.com | www.076591.com | www.c30666.vip | 33382e.com | www.357803.com | www.4963ee.com | 00773zz.com | www.348177.com | www.4136b.com | 5443.com | 531288.com | www.81508y.com | 1156.com | 575799.com | www.260655.com | www.87680h.com | l3410.com | www.flff4.com | www.888zhenren20.com | 5309x.com | 5099tt.com | www.78680n.com | www.7720v.com | 112y.net | www.99jtb.com | www.hgw3300.com | 7744ccc.com | 62105.com | www.961826.com | www.8814e5.com | 93936x.com | www.789755.com | www.7415m.com | hg0088.com | youfa111.vip | www.877719.com | www.00772w.com | www.hg022.com | ak999.net | www.868955.com | www.848777t.com | www.laok111.com | 9420h.com | www.895853.com | www.4078i.com | 4637700.com | 36404433.com | www.587244.com | www.4102p.com | www.345sbet.com | 34q35.com | 9288.us | www.7375.com | www.50021.com | 33115oo.com | 6175a.com | www.775714.com | www.y8821.com | www.345sbet.com | 51133y.com | 11422y.com | www.222067.com | www.ylg1212.com | 44077j.com | 33558448.com | www.197620.com | www.79955.com | www.381818.com | 2247ee.com | bb888833.com | www.373909.com | www.6768991.com | www.76775i.com | 3416f.com | 1145.com | 8827aa.com | www.6539y.com | www.6664ylg.com | www.39695f.com | 3333338722.com | g3405.com | www.622989.com | www.55717u.com | www.860389.com | www.81866t.com | 13825522.com | 55984d.com | www.695756.com | www.680508.com | www.68277999.com | www.551701.com | y68.com | 599729.com | www.80065v.com | www.5854i.cc | www.78919f.com | www.http://976880.com/ | www.986686.com | vipy15.com | 1636.com | 4499buyu.com | www.561502.com | www.68682c.com | www.hgdc600.com | www.12031b.com | www.38200m.com | 655661166.com | 66648t.com | www.33588u.com | www.zcwf2.com | www.5856857.com | www.11c93.com | www.xpj1808.com | www.4759jj.com | yhguangxi.vip | 11oo8332.com | 03508.com | www.155792.com | www.qj63.com | www.33598s.com | www.9187t.com | www.88166j.com | www.935770.com | www.32126t.net | 33115ww.com | 3807p.com | 44ii8331.com | 61788.am | 7552.com | 5589p.com | www.155792.com | www.855310.com | www.16878n.com | www.237377.com | www.46630.app | www.50086.net | www.0234zz.com | www.63877o.com | 8905v.com | hwapp1.com | bcw1111.com | xx888v.com | 9498.me | 52599i.com | www.210793.com | www.880686.com | www.7793d.com | www.7239p.com | www.5856879.com | www.3507777.com | www.3983.com | www.38138s.com | www.bccp877.com | www.569393a.com | www.9hg0066.com | www.u8867.com | www.ag.dl39709.com | www.ylg3099.com | 689030.com | 2306.cm | 预览BY30838.com | 58533333.com | 11yy8332.com | 477105.net | m85686.com | 20778888.com | 2021nnn.com | 9030z.com | 9149s.com | hg1568.com | 2190q.com | gc001.cc | 365004.net | 77665156.com | www.vns0n0.com | www.617709.com | www.63877x.com | www.hg226.cm | www.hg8102.com | www.284444.me | www.y186w.com | www.11447712.com | www.qq599.com | www.890555.com | www.422209.com | www.1389oo.com | www.668cp22.com | www.58118e.com | www.848777e.com | www.480025.com | www.833976.com | www.3775d.com | www.tyc88666.com | www.00840f.com | www.ac3311.com | www.938849.com | www.577285.com | www.199301.com | 50099n.com | 11112007.com | 559649.com | 54249955.com | 8977zz.com | 3122r.com | www.9374y.com | www.h32126.cc | www.88984.com | www.99638i.com | www.371r.cc | www.722563.com | www.303481.com | 1647.cc | 3y4400.com | 007369.com | 3405f.com | blr86.com | www.006635.com | www.505msc.com | www.444230.com | www.9737ww.me | www.52062h.com | www.83033t.com | www.coz5.com | 8522bbbb.com | 85698t.com | 0207206.com | 32126s.net | www.pu5555.net | www.505msc.com | www.hf8855.com | www.5583066.com | www.80065c.com | www.801876.com | 78119988.com | bwinttt.com | r72227.com | www.lpj555.com | www.n9163.com | www.55070d.com | www.44730.com | www.cb6888.com | 11qq8331.com | 492nn.com | 3225c.com | www.66615yy.com | www.i456x.com | www.07770.comm | www.9149c.com | www.339351.com | 118888x.com | 3421x.com | www.js87000.com | www.161514.com | www.40288z.com | www.8667q.com | www.29277o.com | 5437r.com | 00773vv.com | www.990333.net | www.4727188.com | www.77114m.com | www.129177.com | shb777.com | 1077eee.com | www.yao656.com | www.7768js.com | www.663by.com | 5004nn.com | 22098y.com | www.hg22888.net | www.wank3.com | www.6653g.com | www.235961.com | 99567w.com | feicai0394.com | www.6650.bet | www.js8858.com | www.567231.com | 653518.com | 8290i.com | www.178179.com | www.t98478.com | www.504077.com | 35222qq.com | 32355hh.com | www.56655i.com | www.4323h.com | 9193.am | 51133ooo.com | www.js50333.cc | www.8080999d.com | www.896950.com | 23800.com | sss5144.com | www.ggs.99233s.com | www.33588k.com | 81511n.com | 28288.com | www.522118.com | www.6889771.com | www.137518.com | 77606.com | www.pj2256.com | www.pj55712.com | www.335248.com | 59199.com | www.cjcp456.com | www.81608d.com | www.50052o.com | 3552w.com | www.03688.com | www.950058.com | 55797r.com | 2381004.com | www.998855c.com | www.089c.cc | 9949y.com | www.a3a555.cc | www.7225g.com | www.493381.com | 3522vv.cc | www.645886.com | www.9511888.com | 3434aaa.com | 6245a.com | www.5099bb.com | www.792088.com | 0234l.com | www.xpj386.com | www.60123j.com | v2649.com | www.kj638.com | www.8866gvb.com | 996622oo.com | 1144011.com | www.2021e.com | www.339351.com | i8159.cc | www.79500u.com | www.849077.com | 6002j.com | www.589msc.com | www.35918r.com | 4288e.com | www.88807u.com | www.337756.com | 0615010.com | www.h7788y.com | www.js1046.com | v77033.com | www.56520g.com | www.67kk.com | 88535g.com | www.82980.com | www.84499r.com | 83wns88.com | www.83008j.com | www.9356g.com | 1443b.com | www.03345.com | www.959552.com | 3300hhgz.com | www.sb5506.com | 3650585.com | 1489r.com | www.9989579.com | 81366d.com | www.3467o.com | www.09czj.com | 2214v.com | www.hq597.com | www.60123u.com | 5002ttt.com | www.3775n.com | j7736.com | www.551701.com | www.9928b.com | 3285.com | www.3157m.com | 78119988.com | www.hgbb.com | www.65707s.com | 23300g.com | www.938g.cc | www.098303.com | 850834.com | www.959595.la | 80892q.com | www.234k7.com | www.211873.com | 21866i.com | www.0601.com | 2383hh.com | www.20199ss.com | www.81520e.com | www.pj80888.com | www.36787c.com | swtyppp.com | www.04567o.com | 10jqka.com | www.9444hg.com | www.tang777.com | ems6368.com | www.60886a.com | 20059.com | www.1003pj.com | 7720s.com | www.56520g.com | www.ybao9.com | 3189q.com | www.5953688.com | dd8662.com | www.b35yy.com | 2004.com | www.yh95678.com | zyxxd.com | www.333133y.com | www.938454.com | 28yuce.wang | www.50026m.com | 6261nn.com | www.3775p.com | 89777g.com | www.mgm868008.com | aaa678.com | www.low8937.com | 01885b.com | www.hg888995.com | www.055520.cc | www.789sbet.net | www.577690.com | www.7720o.com | www.c760.vip | www.a8a8456.com | www.bei08.com | 6977555.com | www.8039f.com | 3009a.com | www.18593.com | feicai0791.com | www.36788k.com | 9949j.com | www.9478u.com | z2306.com | www.9356q.com | 33115qq.com | www.5dwj.com | www.4759ll.com | www.816820.com | www.333222r.com | www.564846.com | www.9068qq.com | www.257015.com | www.20326.com | 2400017.com | www.66442.com | mgm3242t.com | www.58665j.com | xinvip9.com | www.a063801.com | 37688k.com | www.l63568.com | 650877.com | www.65707g.com | 8827ppp.com | www.hr7888.com | www.wnsr838.com | www.282263.com | www.ytgj444.com | 6830.com | www.4078n.com | 4025o.com | www.566048.com | 7989b.com | www.bei08.com | www.hg0096.com | www.083037.com | www.110741.com | 55zz8331.com | www.44118n.com | 88663015.com | www.5095f.com | www.6491e.com | www.66652a.com | www.3122oo.com | ggg4165.com | www.56011z.com | emr9836.com | www.cp8007.cc | www.7111k.com | haoxialai.com | www.57800d.com | 3765.com | www.5086j.com | www.76543c.com | 3156www.com | www.16181w.com | 3552p.com | www.9818q.cc | www.8694t.com | 6js345.com | www.1559508.com | qmbc6.com | www.994696.com | www.bb7677.com | 4018j.com | www.99094f.com | 7141ww.com | www.197092.com | www.dfh261.com | xxx40033.com | www.6769r.com | www.2846x.com | 55766.com | www.flb477.com | 5350w.com | www.77114i.com | www.4694e.com | 8569844.com | www.960121.com | www.423886.com | 6396x.com | www.50024j.com | www.1238760.com | 08778a.com | www.xb8844.com | www.vns991.cc | 2306p.com | www.7240a.com | www.dfs788.com | 00773e.com | www.xj6006.com | 566670066.com | h151515.com | www.06820j.com | 022570.com | www.77114i.com | www.44mgm777.com | 2381yy.com | 159666j.com | www.8080999d.com | 5651.com | dj0001.com | www.zzyl65.com | www.amjs602.com | 59599b.com | www.86333.com | www.09569p.com | P36.com | www.5854j.cc | www.3494.cc | 04666b.com | www.756693.com | www.38345r.com | c51.cc | nnn444000.com | www.kj111888.com | www.zzzz0266.com | 7720d.net | www.7fk.com | www.5504p.com | 99151e.com | 8569811i.com | www.hd8673.com | www.55268ii.com | 00773z.com | www.hw52.com | www.138cpq.com | 8449ii.com | 2381mmm.com | www.78919c.com | www.h7788k.com | 500000459.com | www.am7979.com | www.98698i.com | d8501.com | 6146n.com | www.56718.com | www.xihu77.com | ued888.com | 20188f.com | www.52303r.com | www.pj5538.com | 4776622.com | 9539n.com | www.81520l.com | www.vns1988.com | 6199w.com | 18887365.com | www.29277j.com | www.jjjj009.com | 931750.com | 8294o.com | www.78gcw.com | www.80969z.com | www.664664.com | 11773885.com | www.622507.com | www.856668.com | www.0860y.com | 33389.cc | tz22777.com | www.99638j.com | www.190bo.com | 6220kk.com | 38820055.com | www.526411.com | www.4809p.com | www.js887788.com | www.1064f.com | ttt2848.com | pj700.cc | www.743633.com | www.8905d.com | www.0686888.com | df8ll.com | 52688g.com | www.937065.com | www.07679v.com | www.hg2020y.com | feicai00886.com | 914910.com | www.528335.com | www.hd8671.com | www.16602g.com | www.033033r.com | 0723.com | 65005.com | www.le05.com | www.184533.com | www.649700.com | 1775mm.com | 3285.com | 3822v.com | www.921599.com | www.c94600.com | www.0866.com | www.ao499.com | 36400022.com | 7376.com | www.483770.com | www.799941.com | www.19yh5.com | www.99927nn.com | 025352.com | 6q604.com | 33115k.com | www.935026.com | www.hg77701.com | www.533163.com | www.5319uuu.com | 3009g.com | 1422.cc | 518cp-6.com | www.544141.com | www.50064p.com | www.30350m.com | www.1122333.com | www.4972uu.com | xpj888c.com | ww0332.com | 3435p.com | www.341011.com | www.07929.cc | www.hg20.co | www.88166s.com | www.xpj3210.com | www.jh839.com | 87965aa.com | 4379c.com | msyz818.com | www.362803.com | www.088wy.com | www.hg81999.com | www.4996bj.com | www.a7817.vip | www.32666h.com | lch8898.com | 01885f.com | 99909n.com | 38238d.com | 58801dh.com | www.574577.com | www.022fj.cc | www.3978h.com | www.js68678.com | www.4694f.com | www.jb33333.com | www.vns2365.com | www.799007.com | 6830w.com | 22dd8331.com | 3568yy.com | dh4005.com | 08820055com | 22wb8.com | www.237988.com | www.769301.com | www.5091z.com | www.529776.com | www.761bbb.com | www.vn777.cn | www.b3065.com | www.j99888.com | www.553525.com | www.jz352.com | www.5197365.com | www.pj0004.com | 67888.am | feicai0917.com | 4809u.com | yhjilin.vip | o67890.com | 3473w.com | 8015r.com | 55882007.com | 4066b.com | 00oo8332.com | 27365a.com | cn.man853.com | vns8d.com | hd2629.com | ttdl4008123.com | 8294f.com | j1759.com | www.50064a.com | www.203552.com | www.392477.com | www.558416.com | www.686536.com | www.946380.com | www.966026.com | www.w635.com | www.jx68.com | www.cp3.xyz | www.cb5588.com | www.hf0886.com | www.c299.com | www.901025.com | www.854766.com | www.975961.com | www.808731.com | www.666407.com | www.572918.com | www.rcw789.com | www.390366.com | www.177534.com | www.50026o.com | 6572u.com | 63305a.com | 3121bb.com | 364860.com | 3614k.com | 预览f8009.com | qqq01234.com | 36405500.com | 8522dddd.com | 2418m.com | fff3304.com | www.1018555.com | www.9996aa.com | www.92220358.com | www.706sunbet.com | www.46621.com | www.983888d.com | www.m80288.com | www.9464002.com | www.69999.am | www.78949n.com | www.5522t.cc | www.771746.com | www.359500.com | 4066yy.com | f5429.com | 4195l.com | 54140011.com | 3522b.vip | www.68666f.com | www.777444j.com | www.3438.cc | www.1168s.com | www.q32031.com | www.5958121.com | www.16878l.com | www.727076.com | www.027107.com | 33333ylg.com | cp088z.com | 3024m.com | gg32355.com | www.309181.com | www.hg8141.com | www.6668a.vip | www.58qp.cc | www.8499s.com | www.655096.com | 923.com | 6033g.com | r67890.com | dd5002.com | www.330099t.com | www.281106.com | www.sdoroviy.com | www.sb4010.com | www.az0908.com | 38238a | 67888e.cc | 26668d.com | www.hg4468.com | www.44166.com | www.9170106.com | www.959595.org | www.hx7766.com | www.35155i.com | 78114411.com | 2096x.com | www.vns383.com | www.34563.com | www.1754p.com | www.68689n.com | www.503477.com | 706809.net | 4461r.com | 9195js.com | www.hg7861.com | www.377666t.com | www.52303f.com | www.282263.com | 3473o.com | 11ii8332.com | www.3332hg.com | www.dzcp5555.com | www.8998887.com | www.763605.com | f5429.com | pjcp.com | www.yddc00.com | www.2302326.com | www.626902.com | www.986656.com | 8988h.com | 3568vv.com | www.7652.cc | www.20199nn.com | www.4923g.com | www.390477.com | 3405v.com | 6220q.com | www.538598.com | www.s2894.com | www.gyfc7.com | xj001a.com | 888333.com | www.67797e.com | www.7415aa.com | www.61655w.com | www.89894i.com | js02749.com | 2008pp.com | www.bet365a7.com | www.hg33382.com | www.307797.com | 8547mm.com | 22335002.com | www.pi111.com | www.502206.com | www.217556.com | 55957k.com | www.xsj900.com | www.rycp051.com | www.54400k.com | 9222.com | 34u35.com | www.698012.com | www.63606n.com | www.803244.com | 20776644.com | hgw168g.com | www.56655l.com | www.52303g.com | 2677ddd.com | xx7742.com | www.hg5779.com | www.4331d.com | www.33588e.com | 40033nn.com | www.20161166.com | www.9955msc.com | www.507285.com | 13806.com | www.67797w.com | www.8883066.com | www.520462.com | bmw8006.com | www.09569i.com | www.858674.com | www.182498.com | 994167.com | www.333423.net | www.764169.com | hy.cc | 3189m.com | www.lzlylc.com | www.7782u.com | c99345.am | www.8520g.com | www.bwin960.co | www.658056.com | www.19019o.com | www.89777s.com | 8868369.com | 2506w.com | www.twcp03.com | www.hy6936.com | 138T.Com | www.r27229.com | www.3775s.com | 22291166.com | 2381aa.com | www.c7205.com | www.901013.com | www5682.com | www.dhy1114.com | www.16065r.com | by305.com | www.1869y.com | www.79095i.com | www.106395.com | 08159s.com | www.79500j.com | www.828916.com | 13222p.com | www.c15595.com | www.ban02.com | b9970.com | www.4719cc.com | www.57578d.com | betaa365.com | www.tyc923.com | www.w77929.com | xiha.ph | www.223456o.com | www.585731.com | 500000931.com | www.38200r.com | www.388158.com | yy634.com | www.yddc06.com | www.0343l.com | 2222k13.com | www.25673c.com | www.55238g.com | jinlong01.com | www.5511sb.com | www.83033k.com | bwinkkk.com | www.g3838.com | www.qmkl0.com | 4018zz.com | www.jy738.com | www.376387.com | 7989i.com | www.9895w.com | 168cp-a.com | www.wnsr878.com | www.7239t.com | 55331zz.com | www.xh0077.com | www.998632.com | wnsr8817.com | www.xybets6.com | 5001q.com | www.a1a444.cc | www.660689.com | 8722llll.com | www.733400.com | www.737884.com | 85722.com | www.73990c.com | 00dd8331.com | www.p8867.com | www.6515.com | 3467l.am | www.bwinyz08.com | 91709.com | www.67797w.com | www.3416c.com | lc99j.com | www.3066vv.com | 060939.com | www.k6572.com | www.hy5503.com | 82299.com | www.3846d.com | 914907.com | www.03543.com | www.324229.com | 1483hh.com | www.83993z.com | m1915m.com | www.16181r.com | k1.z6528.com | www.25288h.com | www.846662.com | 8036kk.com | www.00mgm777.com | c96sg2.com | www.255793.com | 89777o.com | www.350698.com | www.503477.com | www.pj550000.com | www.50024c.com | pj228877.com | www.y8862.com | 5144.com | www.938z.cc | 9411zzz.com | www.448222.com | www.302591.com |