GPS应用论文 第8页
主窗体地图查询代码
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Public Class FormMap
Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click
Dim strSql As String = "select * from street_crossing "
Dim strSql1 As String
Dim jing1 As Single
Dim wei1 As Single
Dim jing2 As Single
Dim wei2 As Single
Dim ds As New DataSet
Dim dbobj As New ConnSqlServer.db
Dim dr As System.Data.SqlClient.SqlDataReader
If txtJingdu.Text = "" Or txtWeidu.Text = "" Then
MessageBox.Show("经度或纬度不能为空!")
Exit Sub
End If
dr = dbobj.DataReader(strSql)
While (dr.Read)
jing1 = dr("j1") - txtJingdu.Text
wei1 = dr("w1") - txtWeidu.Text
jing2 = txtJingdu.Text - dr("j2")
wei2 = txtWeidu.Text - dr("w2")
If (jing1 * wei2 = jing2 * wei1 And jing1 * jing2 >= 0) Then
strSql1 = "select street_name from street_crossing where id =" & dr("id") & ""
dr = dbobj.DataReader(strSql1)
dr.Read()
labStreet.Text = dr("street_name")
Exit Sub
End If
End While
MessageBox.Show("此处不在任何街道上!")
End Sub
Private Sub txtJingdu_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtJingdu.KeyPress
If e.KeyChar >= "0" And e.KeyChar <= "9" Or e.KeyChar = Chr(Keys.Back) Or e.KeyChar = Chr(46) Then
e.Handled = False
Else
e.Handled = True
End If
End Sub
Private Sub txtWeidu_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtWeidu.KeyPress
If e.KeyChar >= "0" And e.KeyChar <= "9" Or e.KeyChar = Chr(Keys.Back) Or e.KeyChar = Chr(46) Then
e.Handled = False
Else
e.Handled = True
End If
End Sub
Private Sub btnMin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMin.Click
If txtStreet.Text = txtEnd.Text And txtEnd.Text <> "" Then
MessageBox.Show("起点和中点不能相同!")
Exit Sub
ElseIf txtEnd.Text = "" Or txtStreet.Text = "" Then
MessageBox.Show("街道名不能为空")
Exit Sub
End If
Dim strSql As String = "select * from road "
Dim strSql1 As String
Dim strSql2 As String
Dim i As Integer
Dim j As Integer
Dim p As Integer
Dim wm As Integer
Dim k As Integer
Dim n As Integer
Dim dr1 As System.Data.SqlClient.SqlDataReader
Dim ds As New DataSet
Dim dbobj As New ConnSqlServer.db
Dim dr As System.Data.SqlClient.SqlDataReader
dr = dbobj.DataReader(strSql)
While (dr.Read)
n = n + 1
End While
n = n + 1
751com.cn
For j = 0 To n
If g(i, j) = 0 Then
g(i, j) = 10000
End If
Next
Next
For i = 0 To n
For j = 0 To n
If i = j Then
g(i, j) = 0
End If
Next
Next
strSql1 = "select * from road where street_name =" & txtStreet.Text & ""
dr = dbobj.DataReader(strSql1)
If dr.Read Then
k = dr("e1id")
Else
MessageBox.Show("无此街道!")
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