vb课件vb第7章幻灯片.pptVIP

* Private Sub Command1_Click() Pos = Val(Text2.Text) If Pos = 0 Or Pos N Then MsgBox 位置越界，请重新输入 Text2.SetFocus Text2.SelStart = 0 Text2.SelLength = Len(Text2.Text) Else For I = Pos To N - 1 A(I) = A(I + 1) Next I N = N - 1 Text3.Text = For I = 1 To N Text3.Text = Text3.Text Str(A(I)) Next I End If End Sub * 【例7-5】将数Num插在数组A中指定的位置Pos 。 如果Pos≤0，则将Num插在第1个位置 如果Pos＞0，则将Num插在最后一个位置 分析: pos Num (1) 对数组中原Pos位置的元素到最后一个元素全部向后移动一个位置: A(N+1)=A(N) A(N)=A(N-1) …… A(Pos+1)=A(Pos) (2) A(Pos)=Num * 设计界面: 在“通用”位置声明: Option Base 1 Dim N As Integer, A() As Integer * 在窗体的Load事件过程中生成20个0到100之间的随机整数，显示于文本框Text1中: Private Sub Form_Load() Text1.Text = N = 20 ReDim A(N) For I = 1 To N A(I) = Int(Rnd * 101) Text1.Text = Text1.Text Str(A(I)) Next I End Sub * Private Sub Command1_Click() 插入 Text4.Text = N = N + 1 Num = Val(Text2.Text) Pos = Val(Text3.Text) ReDim Preserve A(N) Select Case Pos Case Is = 0 For I = N To 2 Step -1 A(I) = A(I - 1) Next I A(1) = Num Case Is = N A(N) = Num * Case Else For I = N To Pos + 1 Step -1 A(I) = A(I - 1) Next I A(Pos) = Num End Select 显示插入后的结果 For I = 1 To N Text4.Text = Text4.Text Str(A(I)) Next I End Sub * 【例7-6】在窗体上输出一个N行、N列、主对角线 和次对角线元素为1，其余元素均为零的矩阵。N由用户指定。 分析: …… 在窗体模块的声明段声明: Option Base 1 Dim A() As Integer 窗体的Click事件过程如下: Private Sub Form_Click() Cls Dim N As Integer, I As Integer, J As Integer N = Val(InputBox(请输入N值, 生成矩阵, _ 4)) ReDim A(N, N) As Integer 根据N定义数组大小 * 生成矩阵 For I = 1 To N For J = 1 To N A(I, J) = 0 If I = J Then A(I, J) = 1 主对角线元素 End If If I + J = N + 1 Then A(I, J) = 1 次对角线元素 End If Next J, I * 按N行N列的格式显示矩阵 For I =