使用pc的并行端口控制5个设备[vb.net 2010] [英] control 5 appliances using pc's parallel port[vb.net 2010]
问题描述
我的电脑的操作系统
windows 7终极32位
------------------- ------
登录访问权限：用户名和密码 - 管理员
i我正在开发一个可以通过pc控制5台设备的项目并行端口/打印机端口。
当我运行程序时，它将首先出现一个登录表单
然后当我进入。
它总是返回这个端口不存在。
即使我有端口也无法检测到它..我不知道我的代码有什么问题。
------------------------------------------------- -------
Dim FILE_NAME As String =LPT1
如果是System.IO.File.Exists（FILE_NAME）然后
Dim objWriter As New System.IO.StreamWriter（FILE_NAME）
objWriter.Write（hi）
objWriter.Close（）
MsgBox（ok）
否则
MsgBox（端口不存在）
结束If
------------------------------------------ - -----------
然后登录后，下一个表格是主页。你会看到开关按钮可以打开和关闭设备。当我点击任何这个按钮时会出现错误提示。它说对象引用未设置为对象的实例
NullReferenceException未处理。
私人Sub btn_app1_Click（ByVal sender As System.Object，ByVal e As System.EventArgs）处理btn_app1.Click
如果btn_app1.Text =ON那么
btn_app1.Text = 关闭
btn_app1.BackColor = Color.Red
io（0）
否则
btn_app1.Text =ON
btn_app1.BackColor = Color.Green
io（1）
结束如果
结束Sub $ / $
Private Sub btn_app2_Click（ByVal sender As System.Object，ByVal e As System.EventArgs）处理btn_app2.Click
如果是btn_app2。 Text =ON然后
btn_app2.Text =OFF
btn_app2.BackColor = Color.Red
io（0）
Else
btn_app2.Text =ON
btn_app2.BackColor = Color.Green
io（2）
结束如果
结束子
私人子btn_app3_Cli ck（ByVal sender As System.Object，ByVal e As System.EventArgs）处理btn_app3.Click
如果btn_app3.Text =ON那么
btn_app3.Text =关闭
btn_app3.BackColor = Color.Red
io（0）
否则
btn_app3.Text = ON
btn_app3.BackColor = Color.Green
io（4）
结束如果
End Sub
Private Sub btn_app4_Click（ByVal sender As System.Object，ByVal e As System.EventArgs）处理btn_app4.Click
如果btn_app4.Text =ON然后
btn_app4.Text =OFF
btn_app4.BackColor = Color.Red
io（0）
Else
btn_app4.Text =ON
btn_app4.BackColor = Color.Green
io（8）
结束如果
End Sub
Private Sub btn_app5_Click（ByVal sender As System.Object，ByVal e As System。 EventArgs）处理btn_app5.Click
如果btn_app5.Text =ON那么
btn_app5.Text =OFF
btn_ap p5.BackColor = Color.Red
io（0）
否则
btn_app5.Text =ON
btn_app5.BackColor = Color.Green
io（16）
结束如果
End Sub
私有子io（ByVal位为整数）
val = axHwinterface1.InPort（888）
axHwinterface1.OutPort（888，CShort（val或bit） ））
结束次级
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请帮我解决这个问题。我需要你的帮助..请提前谢谢..
每一个回复都非常感谢
如果你想看到我的话整个项目你可以在这里下载
http://www.mediafire.com/?1zvx1ty736r2nnb
< blockquote>你绝对不会这样做！
看看这个：未经审查的I / O端口 - 1 - 使用并行端口控制LED（发光二极管） [ ^ ] - 它向您展示了如何使用LED为您想要控制的机器以各种语言进行操作。
请注意，您无法从并行端口为机器供电 - 如果您尝试，可能会损坏您的硬件！
my pc''s operating system
windows 7 ultimate 32 bit
-------------------------
login access: username & password - admin
i am working on a project that will control 5 devices through pc parallel port/printer port.
when i run the program it will first appear a loginform
then when i enter.
it always returns that the port doesnt exist.
even though i have the port it cant detect it.. i dont know what is wrong with my code.
--------------------------------------------------------
Dim FILE_NAME As String = "LPT1"
If System.IO.File.Exists(FILE_NAME) Then
Dim objWriter As New System.IO.StreamWriter(FILE_NAME)
objWriter.Write("hi")
objWriter.Close()
MsgBox("ok")
Else
MsgBox("port does not exist")
End If
------------------------------------------------------
then after the login the next form is homepage. there you''ll see the switch buttons that will turn on and off a device. when i clicked any of this buttons an error will prompt. its say that object reference not set to an instance of an object
NullReferenceException was unhandled.
Private Sub btn_app1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_app1.Click
If btn_app1.Text = "ON" Then
btn_app1.Text = "OFF"
btn_app1.BackColor = Color.Red
io(0)
Else
btn_app1.Text = "ON"
btn_app1.BackColor = Color.Green
io(1)
End If
End Sub
Private Sub btn_app2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_app2.Click
If btn_app2.Text = "ON" Then
btn_app2.Text = "OFF"
btn_app2.BackColor = Color.Red
io(0)
Else
btn_app2.Text = "ON"
btn_app2.BackColor = Color.Green
io(2)
End If
End Sub
Private Sub btn_app3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_app3.Click
If btn_app3.Text = "ON" Then
btn_app3.Text = "OFF"
btn_app3.BackColor = Color.Red
io(0)
Else
btn_app3.Text = "ON"
btn_app3.BackColor = Color.Green
io(4)
End If
End Sub
Private Sub btn_app4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_app4.Click
If btn_app4.Text = "ON" Then
btn_app4.Text = "OFF"
btn_app4.BackColor = Color.Red
io(0)
Else
btn_app4.Text = "ON"
btn_app4.BackColor = Color.Green
io(8)
End If
End Sub
Private Sub btn_app5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_app5.Click
If btn_app5.Text = "ON" Then
btn_app5.Text = "OFF"
btn_app5.BackColor = Color.Red
io(0)
Else
btn_app5.Text = "ON"
btn_app5.BackColor = Color.Green
io(16)
End If
End Sub
Private Sub io(ByVal bit As Integer)
val = axHwinterface1.InPort(888)
axHwinterface1.OutPort(888, CShort(val Or bit))
End Sub
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please help me im new in this.. i need your help guys.. thank you in advance..
every response is very much appreciated
if you want to see my whole project you can Download it here
http://www.mediafire.com/?1zvx1ty736r2nnb
You definitely don''t do it like that!
Have a look at this: I/O Ports Uncensored - 1 - Controlling LEDs (Light Emiting Diodes) with Parallel Port[^] - it shows you how to do it in a variety of languages using LEDs for the machines you want to control.
Do be aware that you can''t power the machines from the parallel port - you will probably damage your hardware if you try!
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