Question

VB 画圆饼图

下列程序运行时，先输入各公司月销售额，然后单击命令按钮，图片框中将显示各公司销售额的圆饼图（如图8-1所示）。要求：在文本框中只能输入数字字符；在圆饼图中分别用红、绿、篮色显示A、B、C公司的扇区填充色。 

Answer 1

窗体上放一个 PictureBox控件 一个 command1 程序运行时会提示让分别输入A B C公司月销售额
程序如下
Private Sub Command1_Click()
Const pi = 3.141593
Dim a As Single, b As Single, c As Single, x As Single
Picture1.Scale (-8, -8)-(8, 8)
Picture1.FillStyle = 0 '实心填充
a = InputBox("请输入A公司销售额")
b = InputBox("请输入B公司销售额")
c = InputBox("请输入C公司销售额")
x = 2 * pi / (a + b + c) ' 计算每个单位在圆饼图中所占圆心角的弧度值
'依次画出3个颜色不同的圆饼图
Picture1.FillColor = RGB(255, 0, 0)
Picture1.Circle (0, 0), 6, 0, -2 * pi, -a * x
Picture1.FillColor = RGB(0, 255, 0)
Picture1.Circle (0, 0), 6, 0, -a * x, -(a + b) * x
Picture1.FillColor = vbBlue
Picture1.Circle (0, 0), 6, 0, -(a + b) * x, -(a + b + c) * x
End Sub
Private Sub Form_Load()
Picture1.Width = Picture1.Height
End Sub