VB24题操作题答案.docx

1、编写程序，使用多分支（Select Case）语句结构对输入的学生成绩给出A、B、C和D四个等级判断。要求，学生成绩由文本框（Text1）输入，结果显示在文本框（Text2）中。评分标准如下： 90≤成绩≤100 A 80≤成绩90 B 60≤成绩80 C成绩60 DPrivate Sub Command1_Click()或者Dim x As Integerx = Val(Text1.Text)Select Case x Case 90 To 100 Text2.Text = A Case Is = 80 Text2.Text = B Case Is = 60 Text2.Text = C Case Is = 0 Text2.Text = D End Select End SubPrivate Sub Command1_Click()Dim x As Integer x = Val(Text1.Text)Select Case x Case 90 To 100 Text2.Text = A Case 80 To 90 Text2.Text = B Case 60 To 80 Text2.Text = C Case Is 60 Text2.Text = D End SelectEnd Sub2、编写程序，使用If块结构语句对输入的学生成绩给出等级判断。要求：学生成绩由文本框（Text1）输入，结果显示在文本框（Text2）中。评分标准如下：成绩60不及格60≤成绩70 及格70≤成绩80 中等80≤成绩90 良好90≤成绩优秀Private Sub Command1_Click()Dim n As Integern = Val(Text1.Text)If n 60 ThenText2.Text = 不及格ElseIf n = 60 And n 70 ThenText2.Text = 及格ElseIf n = 70 And n 80 ThenText2.Text = 中等ElseIf n = 80 And n 90 ThenText2.Text = 良好ElseIf n = 90 And n = 100 ThenText2.Text = 优秀End IfEnd Sub3、求1+2+3+....+n的值，n从文本框Text1输入，请以n=999验证结果。要求：计算结果必须保存在Sum中Private Sub Form_Click()***************** Begin ************** Dim n As Integer, Sum As LongDim i As Integer n = Val(Text1.Text)Sum = 0 For i = 1 To n Sum = Sum + i Next iPrint Sum*************** End ************************* Call TestFunc(Sum)End SubPrivate Sub TestFunc(i As Long) Dim OUT As Integer OUT = FreeFile Open App.Path \out.txt For Output As #OUT Print #OUT, i Close #OUTEnd Sub4、编程实现，运行时，单击出题按钮，产生任意两个[1,100]之间的随机整数显示在文本框Text1和Text2内；单击计算按钮，求这两个数的和显示在文本框Text3内。********** Begin **********Private Sub Command1_Click()Text1.Text = Int(100 * Rnd + 1)Text2.Text = Int(100 * Rnd + 1)End SubPrivate Sub Command2_Click()Text3.Text = Val(Text1.Text) + Val(Text2.Text)End Sub********** End **********5、求1*2*3*....*n的值，n从文本框Text1输入，请以n=9验证结果，结果用Label3输出。要求：计算结果必须保存在F中Private Sub Command1_Click()***************** Begin **************