unity基础开发----unity获取外部设备（方向盘）按键

在unity中可能会用到外部的设备，比如是游戏手柄，赛车的方向盘手柄，在unity中 input manger中最多可以获取到10个按键，但是就像赛车的游戏手柄可能在电脑pc上可以显示，但是在unity中就获取不到了。那我们只能用其他的方法来解决这个问题了。

 using UnityEngine;
 using System.Collections;
 using System.Runtime.InteropServices;

 public class JoystickController : MonoBehaviour {


 public struct JOYINFOEX
 {
 ///
 /// Size, in bytes, of this structure.
 ///
 public int dwSize;
 ///
 /// Flags indicating the valid information returned in this structure. Members that do not contain valid information are set to zero.
 ///
 public int dwFlags;
 ///
 /// Current X-coordinate.
 ///
 public int dwXpos;
 ///
 /// Current Y-coordinate.
 ///
 public int dwYpos;
 ///
 /// Current Z-coordinate.
 ///
 public int dwZpos;
 ///
 /// Current position of the rudder or fourth joystick axis.
 ///
 public int dwRpos;
 ///
 /// Current fifth axis position.
 ///
 public int dwUpos;
 ///
 /// Current sixth axis position.
 ///
 public int dwVpos;
 ///
 /// Current state of the 32 joystick buttons. The value of this member can be set to any combination of JOY_BUTTONn flags, where n is a value in the range of 1 through 32 corresponding to the button that is pressed.
 ///
 public int dwButtons;
 ///
 /// Current button number that is pressed.
 ///
 public int dwButtonNumber;
 ///
 /// Current position of the point-of-view control. Values for this member are in the range 0 through 35,900. These values represent the angle, in degrees, of each view multiplied by 100.
 ///
 public int dwPOV;
 ///
 /// Reserved; do not use.
 ///
 public int dwReserved1;
 ///
 /// Reserved; do not use.
 ///
 public int dwReserved2;
 };

 [DllImport("winmm")] public static extern int joyGetPosEx(int uJoyID, ref JOYINFOEX pji);
 private JOYINFOEX infoEx;
     private string currentButton;
     private string currentAxis;
     private float axisInput;
     // Use this for initialization
     void Start () {
          //Device joystickDevice;
          //JoystickState state;
         infoEx = new JOYINFOEX();
         infoEx.dwSize = Marshal.SizeOf(typeof(JOYINFOEX));
         infoEx.dwFlags=0x00000080;
     }

     // Update is called once per frame
     void Update ()
     {
         getButton();


     }
     ///
     /// get the button data of the joystick
     ///
     void getButton()
     {


         int e = joyGetPosEx(0,ref infoEx);
         if (e==0)
         {
             int mask=0x10;
             string str = string.Empty;
             for(int i=5;i<32;i++)
             {
                 if ((infoEx.dwButtons & mask) > 0)
                 {
                     str = str + string.Format("button({0})",i);
                 }
                 mask = mask << 1;
             }
             Debug.Log(str);
         }

     }
 }

这样就可以全部获取到在pc上可以显示按键。