实用计算器之程序设计
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[摘 要]多用计算器的构思及设计代码
[关键词]多用计算器；设计
数值计算可以说是日常最频繁的工作了，WIN98提供了“计算器”软件供用户使用，该软件可以处理一般的一步四则运算，例如：3+2、5/3等等，但在日常中用户经常遇到多步四则运算问题，例如：3+4*5-4/2，45*34/2+18*7等等，那么该个计算器就无法胜任了，作者制作了一个实用的计算器，该计算器新增不少功能：（程序界面如图）
1．可以实现连续的四则运算
2．可以实现输入式子的显示
3．可以方便计算个人所得税
4．鼠标、键盘均可输入数据
5．操作界面友好
6．击键可发声
构建该个计算器所需研究及解决的核心问题有如下几个：1、连乘求值?2、字符显示 3、键盘输入?4、击键发声?5、个人所得税法规，为了使大家对程序有更一步认识，现将代码提供给读者参考：
*定义数组及窗体变量
Dim number2(0 To 50) As Double
Dim number(0 To 50) As Double
Dim z As Integer
Dim k As Integer, r As Integer
Dim j As Integer
Dim str As String
*调用名为“playsound”的API函数
Private Declare Function PlaySound Lib "winmm.dll" Alias "PlaySoundA" (ByVal lpszName As String, ByVal hModule As Long, ByVal dwFlags As Long) As Long
Private Const SND_FILENAME = H20000?
Private Const SND_ASYNC = H1?
Private Const SND_SYNC = H0
*判断通用过程
Sub pianduan(p As String)
r = 0
Dim i As Integer, l As Integer, h As Integer
h = 0
i = 1
If InStr(Trim$(p), "*") 0 Then
k = k + 1
End If
If InStr(Trim$(p), "/") 0 Then
r = r + 1
End If
End Sub
*连乘通用过程(略)
*各按钮事件过程
Private sub Command1_Click(Index As Integer)
PlaySound App.Path "\start.wav", 0, SND_SYNC
Text1.Text = Text1.Text + Command1(Index).Caption
Text2.Text = Text2.Text + Command1(Index).Caption
Text1.SetFocus
End Sub
rivate sub Command10_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
str = Text3.Text
End Sub
Private sub Command11_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Text3.Text = str
End Sub
rivate sub Command2_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Dim totle As Double
Dim n As Integer
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
Text2.Text = Text2 + "+"
z = z + 1
Text1.SetFocus
End Sub
rivate sub Command3_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Dim totle As Double
Dim n As Integer
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
Text2.Text = Text2 + "-"
Text1.Text = Text1.Text "-"
z = z + 1
Text1.SetFocus
End Sub
Private sub Command4_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Text2.Text = Text2.Text + "*"
Text1.Text = Text1.Text + "*"
Text1.SetFocus
End Sub
rivate sub Command5_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Text2.Text = Text2 + "/"
Text1.Text = Text1 + "/"
Text1.SetFocus
End Sub
Private sub Command6_Click()
PlaySound App.Path "\sound.wav", 0, SND_SYNC
Dim totle As Double
Dim n As Integer
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
z = z + 1
Dim dengyu As Double
Dim v As Integer
For v = 0 To 50
dengyu = dengyu + number2(v)
Next v
If dengyu 0 Then
Text3.ForeColor = HFF
Else
Text3.ForeColor = HFF0000
End If
Text3.Text = dengyu
Text1.SetFocus
If Len(Text3.Text) = 14 Then
calcresult.Show
End If
End Sub
rivate sub Command7_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
z = 0: k = 0: r = 0: j = 0
Dim i As Integer
For i = 0 To 50
number(i) = 0
number2(i) = 0
Next i
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Text1.SetFocus
End Sub
rivate sub Command8_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
If Val(Text3.Text) = 0 Then
MsgBox "除数不能为0！"
Exit Sub
End If
Text3.Text = 1 / Val(Text3.Text)
End Sub
Private sub Command9_Click()
PlaySound App.Path "\start.wav", 0, SND_SYNC
Text3.ForeColor = HFF0000
Text3.Text = Val(Text3.Text) * Val(Text3.Text)
End Sub
rivate sub muninternet_Click()
Dim i
i = Shell("C:\Program Files\InternetExplorer\iexplore.exe", vbMaximizedFocus)
End Sub
rivate sub munmp3_Click()
Dim i
i = Shell("C:\Program Files\Windows Media Player\mplayer2", vbNormalNoFocus)
End Sub
Private sub munsm_Click()
Dialog.Show
End Sub
rivate sub muntax_Click()
tax.Show
End Sub
rivate sub munver_Click()
ver.Show
End Sub
rivate sub notepad_Click()
Dim i
i = Shell("c:\windows\notepad", vbNormalFocus)
End Sub
Private sub Text1_KeyPress(KeyAscii As Integer)
PlaySound App.Path "\start.wav", 0, SND_SYNC
Dim num As Integer
num = Val(KeyAscii)
If num 47 And num 58 Then
Text1.Text = Text1.Text + CStr(num - 48)
Text2.Text = Text2.Text + CStr(num - 48)
End If
If num = 46 Then
Text1.Text = Text1.Text + "."
Text2.Text = Text2.Text + "."
End If
If KeyAscii = 43 Then
Dim totle As Double
Dim n As Integer
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
Text2.Text = Text2 + "+"
z = z + 1
End If
If KeyAscii = 45 Then
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
Text2.Text = Text2 + "-"
Text1.Text = Text1.Text "-"
z = z + 1
End If
If KeyAscii = 42 Then
Text2.Text = Text2.Text + "*"
Text1.Text = Text1.Text + "*"
End If
If KeyAscii = 47 Then
Text2.Text = Text2.Text + "/"
Text1.Text = Text1.Text + "/"
End If
If KeyAscii = vbKeyReturn Then
PlaySound App.Path "\sound.wav", 0, SND_SYNC
Call pianduan(Text1.Text)
If k = 1 Or r = 1 Then
Call liancheng(totle)
number2(z) = totle
If Mid$(Trim$(Text1.Text), 1, 1) = "-" Then
number2(z) = -totle
End If
k = 0: r = 0
Else
number2(z) = Val(Text1.Text)
End If
Text1.Text = ""
z = z + 1
Dim dengyu As Double
Dim v As Integer
For v = 0 To 50
dengyu = dengyu + number2(v)
Next v
If dengyu 0 Then
Text3.ForeColor = HFF
Else
Text3.ForeColor = HFF0000
End If
Text3.Text = dengyu
End If
If KeyAscii = vbKeyEscape Then
z = 0: k = 0: r = 0: j = 0
Dim i As Integer
For i = 0 To 50
number(i) = 0
number2(i) = 0
Next i
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Text1.SetFocus
End If
If Len(Text3.Text) = 14 Then
calcresult.Show
End If
End Sub
rivate sub Text3_Change()
tax2.Text1 = Text3.Text
End Sub
是这样的，C语言在编译时候是顺序编译的 ，也就是说，如果被调用的函数是在调用函数之前被声明过，就可以通过编译，反之就会报错。
你这个有两种解决方案，1，在程序最开始声明所有函数 2，把float jian(float a;float b;)这函数所有内容放到main（）前面
#includestdio.h
#includestdlib.h
double jia(double a,double b)
{
return a+b;
}
double jian(double a,double b)
{
return a-b;
}
double cheng(double a,double b)
{
return a*b;
}
double chu(double a,double b)
{
return a/b;
}
double juedui(double a)
{
return a0 ? a : -a;
}
double chengfang(double a,double b)
{
return pow(a,b);
}
double sinx(double a)
{
return sin(a);
}
int main()
{
int m;
double a,b;
while(1)
{
printf("请输入第一个操作数：");
scanf("%lf",a);
printf("0、退出\n1、加\n2、减\n3、乘\n4、除\n5、绝对值\n6、乘方\n7sin、\n请选择一个：");
scanf("%d",m);
if(1==m || 2==m || 3==m || 4==m || 6==m)
{
printf("请输入第二个操作数：");
scanf("%lf",b);
}
switch(m)
{
case 0:
exit(0);
break;
case 1:
printf("%lf+%lf=%lf\n",a,b,jia(a,b));
break;
case 2:
printf("%lf-%lf=%lf\n",a,b,jian(a,b));
break;
case 3:
printf("%lf*%lf=%lf\n",a,b,cheng(a,b));
break;
case 4:
if(0.0==b)
{
printf("除数不能为0。\n");
}
else
{
printf("%lf/%lf=%lf\n",a,b,chu(a,b));
}
break;
case 5:
printf("|%lf|=%lf\n",a,juedui(a));
break;
case 6:
printf("%lf的%lf方=%lf\n",a,b,chengfang(a,b));
break;
case 7:
printf("sin(%lf)=%lf\n",a,sinx(a));
break;
default:
printf("无法处理的命令。\n");
break;
}
}
system("PAUSE");
return EXIT_SUCCESS;
}
C语言都是先定义后使用的
通过函数名调用如：
double
sum(double
x,double
y)
{
double
z;
z=x+y;
retun(z);
}
main()
{
double
h;
double
a,b;
h=sum(a,b);
}
