everyone: how to read/write usb device with delphi language,I try to use windows API function to realize,but when i call SetupDiEnumDeviceInterfaces,it always fail,i don't know why?where can i find the delphi program the follows is my program procedure TForm1.Button1Click(Sender: TObject); var gGuid:TGuid; ghDevInfo:HDEVINFO; MemberIndex:DWORD; DeviceInterfaceData:TSPDeviceInterfaceData; ifDetail:PSPDeviceInterfaceData; length:DWORD; begin HidD_GetHidGuid(gGuid); ghDevInfo:=SetupDiGetClassDevs(@gGuid,nil,0,DIGCF_PRESENT OR DIGCF_INTERFACEDEVICE); if (ghDevInfo=nil) then begin showmessage('ERROR,the program will exit'); exit; end else begin showmessage('SUCCESS'); end; DeviceInterfaceData.cbSize:=sizeof(DeviceInterfaceData); //showmessage(inttostr(DeviceInterfaceData.cbSize)); if (SetupDiEnumDeviceInterfaces(ghDevInfo,0,gGuid,MemberIndex,DeviceInterfaceData)=False) then begin showmessage('can't find hid device'); if MemberIndex<>0 then showmessage(inttostr(MemberIndex)); end; SetupDiGetDeviceInterfaceDetail(ghDevInfo,@DeviceInterfaceData,nil,0,@length,nil); ...... end; although i plug a hid device,the funcion SetupDiEnumDeviceInterfaces always return fail,i don't know why? wzjych

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wzjych

wzjych您好：

 if (SetupDiEnumDeviceInterfaces(ghDevInfo,0,gGuid,MemberIndex,DeviceInterfaceData)=False) then
    begin
      showmessage('can"t find hid device'); //改'为"
      if MemberIndex<>0 then
        showmessage(inttostr(MemberIndex));
    end;

小弟对usb device的读取没实践过，不过您可以参考下面： http://delphi.ktop.com.tw/topic.php?topic_id=38317 http://delphi.ktop.com.tw/topic.php?topic_id=63380 hope helpful! ============================ 为什么经过多年以后，得失的过程如此冷漠 ============================

http://www.efg2.com/Lab/Library/Delphi/IO/PortIO.htm

小弟編譯後出現下面錯誤, 請問是否要 uses 甚麼? 或者放甚麼元件? 或要做其他事情 ?

[Error] Unit1.pas(29): Undeclared identifier: 'HDEVINFO'
[Error] Unit1.pas(31): Undeclared identifier: 'TSPDeviceInterfaceData'
[Error] Unit1.pas(32): Undeclared identifier: 'PSPDeviceInterfaceData'
[Error] Unit1.pas(35): Undeclared identifier: 'HidD_GetHidGuid'
[Error] Unit1.pas(36): Undeclared identifier: 'SetupDiGetClassDevs'
[Error] Unit1.pas(36): Undeclared identifier: 'DIGCF_PRESENT'
[Error] Unit1.pas(36): Undeclared identifier: 'DIGCF_INTERFACEDEVICE'
[Warning] Unit1.pas(36): Combining signed and unsigned types - widened both operands
[Error] Unit1.pas(37): Operator not applicable to this operand type
[Error] Unit1.pas(47): Missing operator or semicolon
[Error] Unit1.pas(49): Undeclared identifier: 'SetupDiEnumDeviceInterfaces'
[Error] Unit1.pas(55): Undeclared identifier: 'SetupDiGetDeviceInterfaceDetail'
[Fatal Error] Project1.dpr(5): Could not compile used unit 'Unit1.pas'

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編輯記錄

<code>
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, AppEvnts, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
Label1: TLabel;
private
{ Private declarations }
procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.WMDeviceChange (var Msg: TMessage);
var
myMsg : String;
begin
Case Msg.WParam of
32768:
begin
myMsg :='U盘插入';
Label1.Caption:=myMsg
end;
32772:
begin
myMsg :='U盘拔出';
Label1.Caption:=myMsg;
end;
end;
end;

end.


希望对你有用。

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断断续续的学了几年，还是一个初学者，永远支持Delphi !

2009 .Net HID library C++ VB C#
http://sites.google.com/site/hidlibrary/

http://jedi-apilib.sourceforge.net/scapi_current.zip

可參考裡面的 Demo code!