实验3编写四则运算程序选择.doc

实验3 编写四则运算程序实验目的：1、 掌握VB常量的定义和使用方法；2、 掌握各种表达式的使用方法；3、 掌握常用函数的使用方法；4、 掌握选择结构的程序设计方法。实验内容:1、 实验要求 运行时，能够随机产生加、减、乘、除四则运算，并对用户输入的答案进行判断，并在Picture控件上显示判断结果。2、分析设计用随机函数Rnd()产生随机数和运算符，并利用函数Val()将文本框内容转换为数值型进行运算。3、窗体属性对象名属性名设置值Label1caption显示题目Label2caption题次Text1text计算结果Picture1Picture-Command1caption计分Command2caption继续Command3caption退出4、窗体设计5、源代码Dim i As IntegerDim result As IntegerDim ok As Integer, error As IntegerPrivate Sub Command1_Click()Label1 = Text1.Visible = FalsePicture1.Print - - - - - - - - - - - - - - - -Picture1.Print 你一共计算 & i & 题，;Picture1.Print 得分为： & Int(ok / i * 100)End SubPrivate Sub Command2_Click() Text1.Visible = True Picture1.Cls Text1.SetFocus Form_LoadEnd SubPrivate Sub Command3_Click()EndEnd SubPrivate Sub Form_Load() Label2.Caption = 第 & i + 1 & 题： Dim x As Integer, y As Integer, z As Integer, temp As Integer Dim op As String Randomize x = Int(9 * Rnd) y = Int(8 * Rnd +1) z = Int(4 * Rnd + 1) Text1 = Select Case z Case 1 op = + result = x + y Case 2 op = - If x y Then temp = x: x = y: y = temp End If result = x - y Case 3 op = result = x * y Case 4 op = If x / y x y Then Form_Load Exit Sub End If result = x / yEnd SelectLabel1.Caption = x & op & y & =End SubPrivate Sub Text1_KeyPress(KeyAscii As Integer) If KeyAscii = 13 Then If Val(Text1.Text) = result Then Picture1.Print Label1.Caption; Text1.Text; Tab(10); ok = ok + 1 Else Picture1.Print Label1.Caption; Text1.Text; Tab(10); End If Text1 = Text1.SetFocus