利用两点的经纬度来计算这两点之间的距离

Imports System.Data

Imports System.Math

Imports System.Net

Imports System.IO

Imports System.Windows

'导入对应的名称空间

'数学的计算方法，

'程序的实现很简单

Public Class Diss

Public Const Ea As Double = 6378137 '赤道半径

Public Const Eb As Double = 6356725 '极半径

Public Ec1 As Double = 0.0

Public Ed1 As Double = 0.0

Private j1 As Double = 0.0

Private w1 As Double = 0.0

Private jd1 As Double = 0.0

Private wd1 As Double = 0.0

Public Ec2 As Double = 0.0

Public Ed2 As Double = 0.0

Private j2 As Double = 0.0

Private w2 As Double = 0.0

Private jd2 As Double = 0.0

Private wd2 As Double = 0.0

Private Sub BtnCalc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCalc.Click

Dim dx As Double = 0.0

Dim dy As Double = 0.0

Dim d As Double = 0.0

jd1 = Me.TbJ1.Text.Trim.ToString()

wd1 = Me.TbW1.Text.Trim.ToString()

jd2 = Me.TbJ2.Text.Trim.ToString()

wd2 = Me.TbW2.Text.Trim.ToString()

j1 = jd1 * Math.PI / 180

w1 = wd1 * Math.PI / 180

Ec1 = Eb + (Ea - Eb) * (90 - wd1) / 90

Ed1 = Ec1 * Math.Cos(w1)

j2 = jd2 * Math.PI / 180

w2 = wd2 * Math.PI / 180

Ec2 = Eb + (Ea - Eb) * (90 - wd2) / 90

Ed2 = Ec2 * Math.Cos(w2)

dx = (j2 - j1) * Ed1

dy = (w2 - w1) * Ec1

d = Math.Sqrt(dx * dx + dy * dy)

Me.TextBox5.Text = d.ToString()

End Sub

Private Sub BtnCancel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles BtnCancel.Click

Me.Close()

End Sub

End Class