C#程序设计 输入三角形三边长，并计算的周长和面积
前台有五个TextBox，分别是FirstTxt,SecondTxt,ThridTxt(代表a,b,c三边长),areaTxt,aroundTxt(代表面积，周长),一个计算的Button。
对输入进行了控制，对是否可形成三角形进行了控制，最终计算。计算三角形面积用的是海伦公式。
下面是源码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;
namespace triangle
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public double Alength;
public double Blength;
public double Clength;
private Regex reg = new Regex("^(0|[1-9][0-9]*)$");
//用于检测的正则表达式
//只能输入0或者非0开头的数字
private void Form1_Load(object sender, EventArgs e)
{
this.FirstTxt.Text = "1";
this.SecondTxt.Text = "1";
this.ThirdTxt.Text ="1";
}
private bool TestTriangle(double a,double b,double c)
{//测试是否能形成三角形
double result1 = a + b;
double result2 = a + c;
double result3 = b + c;
if (result1>c&&result2>b&&result3>a)
{
return true;
}
else
{
return false;
}
}
private double CountArea(double a,double b,double c)
{//计算面积
double p = (a+b+c)/2;
double area = Math.Sqrt(p * (p - a) * (p - b) * (p - c));
return area;
}
private double CountAround(double a,double b,double c)
{//计算边长
return a + b + c;
}
private void count_Click(object sender, EventArgs e)
{
if (reg.IsMatch(this.FirstTxt.Text)&®.IsMatch(this.SecondTxt.Text)&®.IsMatch(this.ThirdTxt.Text))
{
Alength = Double.Parse(this.FirstTxt.Text);
Blength = Double.Parse(this.SecondTxt.Text);
Clength = Double.Parse(this.ThirdTxt.Text);
if (TestTriangle(Alength, Blength, Clength))
{
this.aroundtxt.Text = CountAround(Alength, Blength, Clength).ToString();
this.areatxt.Text = CountArea(Alength, Blength, Clength).ToString();
}
else
{
MessageBox.Show("当前不形成三角形!");
}
}
else
{
MessageBox.Show("请输入合法的边长值！");
}
}
}
}
