VB期末考试复习.doc

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1、VB期末考试复习1、判断分数等级（if.end if 和 select case）Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim score As Integer 定义一个变量，保存分数的 score = Integer.Parse(Me.TextBox1.Text) 下面开始判断分数等级 If score 100 Or score = 90 Then MessageBox.Show

2、(优秀！) ElseIf score = 80 Then MessageBox.Show(良好！) ElseIf score = 60 Then MessageBox.Show(及格！) Else MessageBox.Show(不及格！) End If End SubEnd Class例：Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim score As Single Try 把可能

3、出错的代码写在try的下面 score = Single.Parse(Me.TextBox1.Text) Select Case score Case 100 MessageBox.Show(满分) Case 90 To 99 MessageBox.Show(优秀) Case 80 To 89 MessageBox.Show(良好) Case 60 To 79 MessageBox.Show(及格) Case 0 To 59 MessageBox.Show(不及格) Case Else MessageBox.Show(分数无效) End Select Catch ex As Exception

4、 只要有错，就把错误信息显示出来 MessageBox.Show(ex.Message) End Try End SubEnd Class2、for next 循环结构代码：Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim i, s As Integer For i = 1 To 99 Step 2 s = s + i Next MsgBox(1+3+.+99= & s) End Su

5、b/求斐波那契级数 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click Dim a, b, i As Long Dim t As Long Dim s As String a = 1 b = 1 s = a & , & b & , For i = 3 To 90 t = a + b s = s & t & , If i Mod 6 = 0 Then s = s & Chr(10) End If a = b b = t Next Ms

6、gBox(s)End SubPrivate Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click用数组来保存斐波那契级数 Dim f(20) As Long Dim i As Integer 定义字符串变量s,初始值为“空”；作用：把各个元素连接成一个字符串 Dim s As String = 定义字符串s，作用：把各个元素连接一个字符串 f(1) = 1 f(2) = 1 计算斐波那契级数，从第项开始算 For i = 3 To 20 f(i) =

7、 f(i - 1) + f(i - 2) Next For i = 1 To 20 s = s & f(i) & , 把各元素连接起来 下面控制一行输出多少个元素 If i Mod 5 = 0 Then s = s & Chr(10) End If Next 显示结果 MsgBox(s) End Sub/九九乘法表 Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click Dim i As Integer, j As Integer Di

8、m s As String = For i = 1 To 9 For j = 1 To i s &= i & * & j & = & i * j & , Next s &= vbCrLf Next MsgBox(s) End SubEnd Class代码：Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 第一种定义数组的方法 指明了数组下标的上限 Dim a(5) As Integer 定义一

9、个数组a,最大下标为，表示可以存个元素 a(0) = 10 a(1) = 20 a(2) = 30 a(3) = 40 a(4) = 50 a(5) = 60 Dim i As Integer For i = 0 To 5 MsgBox(第 & i + 1 & 个元素的值为： & a(i) Next End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click 第二种定义数组的方法 不指明数组下标的下限 Dim a() As

10、String = as, sf, fsg, gge MsgBox(元素的长度即元素的个数： & a.Length) Dim i As Integer For i = 0 To a.Length - 1 MsgBox(第 & i + 1 & 个元素的值为： & a(i) Next End SubEnd ClassPublic Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 首先判断账号是否录入 If Me.

11、TextBox1.Text = Then MessageBox.Show(请输入账号) Me.TextBox1.Focus() Exit Sub End If 接下来判断密码是否录入 If Me.TextBox2.Text.Length = 0 Then MessageBox.Show(密码不能为空，请录入！) Me.TextBox2.Focus() Exit Sub End If 最后判断帐号和密码是否合法 If Me.TextBox1.Text = And Me.TextBox2.Text = 123 Then MessageBox.Show(合法用户) Else 条件不成立，执行Else

12、下面的代码 MessageBox.Show(账号或密码有错，请联系管理员！) End If End SubEnd Class3、MDI窗体的应用(把设置父窗体的IsMdiContainer属性为true)菜单栏Text：用来指示菜单项的标题.还可以通过在要用作访问键的字符前放置一个”&”来指定访问键.或在其中输入”-”来创建菜单项为分割线Checked：设置菜单项是否被选中，True为选中，False为未选中Name：设置菜单项的名字ShortcutKeys：指定可由菜单项的快捷键Enabled：指定菜单项是否可用Visible：指定菜单项是否可见Image:为菜单项添加图标点击“查询人员信息

13、”，可以链接到查询人员信息窗体.代码：Public Class Form1 Private Sub 查看机构信息ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 查看机构信息ToolStripMenuItem.Click 单击本菜单项时显示“机构信息窗体” frmDepInfo.MdiParent = Me 指定父窗体Me，它就变成子窗体了 frmDepInfo.Show() frmDepInfo.Focus() End Sub Private Sub 编辑机构

14、信息ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 编辑机构信息ToolStripMenuItem.Click frmEditDepInfo.MdiParent = Me frmEditDepInfo.Show() frmEditDepInfo.Focus() End Sub Private Sub 查看人员信息ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.Ev

15、entArgs) Handles 查看人员信息ToolStripMenuItem.Click frmCKperInfo.MdiParent = Me frmCKperInfo.Show() frmCKperInfo.Focus() End Sub Private Sub 编辑人员信息ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 编辑人员信息ToolStripMenuItem.Click frmBJperInfo.MdiParent = Me frmBJper

16、Info.Show() frmBJperInfo.Focus() End Sub Private Sub 查看帐号ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 查看帐号ToolStripMenuItem.Click frmCKnum.MdiParent = Me frmCKnum.Show() frmCKnum.Focus() End Sub Private Sub 修改密码ToolStripMenuItem_Click(ByVal sender As Sy

17、stem.Object, ByVal e As System.EventArgs) Handles 修改密码ToolStripMenuItem.Click frmXGpassport.MdiParent = Me frmXGpassport.Show() frmXGpassport.Focus() End Sub Private Sub 添加帐号ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 添加帐号ToolStripMenuItem.Click frmAdd

18、Num.MdiParent = Me frmAddNum.Show() frmAddNum.Focus() End Sub Private Sub 退出ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 退出ToolStripMenuItem.Click Application.Exit() End SubEnd Class4、面向对象的类的使用使用类代码：Public Class Form1 Private Sub Button1_Click(ByVal sen

19、der As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 使用类来定义变量（这个变量一般叫对象） 定义的时候用New关键字 Dim myCat As New Cat MsgBox(这只猫还没有名字，因为还没有给它取名 & myCat.catsName) 下面给它取名字 其实就是访问属性“CatName”，用“对象名.属性名”访问 myCat.catsName = 小花 myCat.catsAge = 2 myCat.catsColur = 黑色 MsgBox(这只猫叫： & myCat.catsName &

20、 ，养了 & myCat.catsAge & 年了 & ，是 & myCat.catsColur) End SubEnd Class定义类代码：Public Class Cat 定义一个字段,private访问级别 Private CatName As String Private CatAge As Integer Private CatColur As String 定义一个属性，属性一定和某个字段相对应的 其作用：取得某字段的值或给字段赋值 Public Property catsName() As String Get Return CatName End Get Set(ByVal

21、value As String) CatName = value End Set End Property Public Property catsAge() As Integer Get Return CatAge End Get Set(ByVal value As Integer) CatAge = value End Set End Property Public Property catsColur() As String Get Return CatColur End Get Set(ByVal value As String) CatColur = value End Set E

22、nd PropertyEnd Class计算矩形的表面积和体积的类的使用使用类的过程代码：Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim c As New MyCube c.Length = Double.Parse(Me.TextBox1.Text) c.Width = Double.Parse(Me.TextBox2.Text) c.Height = Double.Parse(M

23、e.TextBox3.Text) Me.TextBox4.Text = c.tiji() Me.textbox5.text = c.Bmj() End Sub End Class定义类的过程代码：Public Class MyCube Private L As Double Private W As Double Private H As Double Public Property Length() As Double Get Return L End Get Set(ByVal value As Double) L = value End Set End Property Public P

24、roperty Width() As Double Get Return W End Get Set(ByVal value As Double) W = value End Set End Property Public Property Height() As Double Get Return W End Get Set(ByVal value As Double) H = value End Set End Property 定义计算矩形的体积的类 Public Function tiji() As Double Dim v As Double v = L * W * H Return

25、 v End Function 定义计算矩形表面积的类 Public Function Bmj() As Double Dim s As Double s = L * W * 2 + L * H * 2 + W * H * 2 Return s End FunctionEnd Class通过使用类来获取个人信息1、定义类personPublic Class person 定义私有字段 Private name As String Private age As Integer 构造无参数的函数 Public Sub New() name = 小林 age = 21 End Sub 构造两个有参数

26、的函数 Public Sub New(ByVal x As String, ByVal y As Integer) name = x age = y End Sub 通过定义function来获取信息 Public Function Getname() As String Return name End Function Public Function Getage() As Integer Return age End FunctionEnd Class2、使用类的过程代码：Public Class Form1 Private Sub Button1_Click(ByVal sender A

27、s System.Object, ByVal e As System.EventArgs) Handles Button1.Click 使用有参数的类 Dim p As New person Me.TextBox1.Text = p.Getname Me.TextBox2.Text = p.Getage End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click 使用无参数的类 Dim p As New person(大民,

28、 45) Me.TextBox1.Text = p.Getname Me.TextBox2.Text = p.Getage End SubEnd Class5、如何编写精确查找和模糊查找Public Class Form1 Private Sub RecordsBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Me.Validate() Me.RecordsBindingSource.EndEdit() Me.RecordsTableAdapter.Update(

29、Me.StudentDataSet.Records) End Sub Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load TODO: 这行代码将数据加载到表“StudentDataSet.Records”中。您可以根据需要移动或移除它。 Me.RecordsTableAdapter.Fill(Me.StudentDataSet.Records) End Sub Private Sub Button1_Click(ByVal sender As

30、 System.Object, ByVal e As System.EventArgs) Handles Button1.Click If Me.TextBox1.Text.Length = 0 Then MsgBox(请输入姓名！) End If Me.RecordsTableAdapter.FillByName(Me.StudentDataSet.Records, Me.TextBox1.Text) End Sub Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Ha

31、ndles Button3.Click 按姓名模糊查找 Me.RecordsTableAdapter.FillBylikeName(Me.StudentDataSet.Records, % + Me.TextBox1.Text + %) End Sub Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click 按家庭住址查找 Me.RecordsTableAdapter.FillByADDr(Me.StudentDataSet.Recor

32、ds, % + Me.TextBox3.Text + %) End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click Me.RecordsTableAdapter.FillByNum(Me.StudentDataSet.Records, Me.TextBox2.Text) End SubEnd Class6、如何用vb 编写查找人员的基本信息Public Class Form1 Private Sub RecordsBin

33、dingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Me.Validate() Me.RecordsBindingSource.EndEdit() Me.RecordsTableAdapter.Update(Me.StudentDataSet.Records) End Sub Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.L

34、oad TODO: 这行代码将数据加载到表“StudentDataSet.Records”中。您可以根据需要移动或移除它。 Me.RecordsTableAdapter.Fill(Me.StudentDataSet.Records) End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim str As String = Nothing str =编号like %1% 如果录了编号信息，表示只有编号作为条件 If

35、Me.TextBox1.Text.Length 0 Then str = 编号like % & Me.TextBox1.Text & % End If If Me.TextBox2.Text.Length 0 Then str = 姓名like % & Me.TextBox2.Text & % End If 如果录入了编号和姓名信息，表示这两个字段作为条件 If str Nothing And Me.TextBox2.Text.Length 0 Then 如果str=nothing,并且姓名“不为空”，那么仅把姓名作为条件 str = str & and 姓名like % & Me.TextB

36、ox2.Text & % 表示只录入姓名，但不录入编号 ElseIf Me.TextBox2.Text.Length 0 Then str = 姓名like % & Me.TextBox2.Text & % End If If str Nothing And Me.ComboBox1.Text.Length 0 Then str = str & and 性别like % & Me.ComboBox1.Text & % ElseIf Me.ComboBox1.Text.Length 0 Then str = 性别like % & Me.ComboBox1.Text & % End If filt

37、er属性为过滤条件，根据条件筛选记录 Me.RecordsBindingSource.Filter = str End SubEnd Class7、8、按手机号码查询Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load TODO: 这行代码将数据加载到表“StudentDataSet.Records”中。您可以根据需要移动或移除它。 Me.RecordsTableAdapter.Fill(Me.StudentDataSet.Reco