Unity Input
Unity需要通过键盘、鼠标、手柄、摇杆来获取玩家对游戏的控制。你可以在 Input窗口设置按钮和虚拟轴，在代码中通过Input类监听玩家控制。游戏发布后玩家也可以在设置对话框中自行设置相关按键。
添加及设置输入轴
Unity中打开Edit->Project Settings->Input面板，界面如下：
此项目中只有10个输入轴，如果你想添加自己的输入轴，只需要更改Size属性。Size表示你所有输入轴的数量。接下来我们看下每个输入轴里面的各个属性。
* Name： 该输入轴的名称，相当于ID，在代码中我们可以根据该属性引用对应的输入轴；
* Descriptive Name： 游戏设置对话框中输入轴的名称，方便玩家设置对应按键；
* Descriptive Negative Name： 和Descriptive Name差不多，只是表示相反方向；
* Negative Button ：对应于键盘、鼠标、手柄上的按键，并且是该控制的反向轴；
* Positive Button： 对应于键盘、鼠标、手柄上的按键，并且是该控制的正向轴；
* Alt Negative Button： Negative Button的备选按键；
* Alt Positive Button： Positive Button的备选按键；
* Gravity： 当不再按下此按键的时候，该输入轴的数值会以Gravity的速度变为默认值；
* Dead： 盲区。如果输入轴数值在此范围内，则以默认值替换；
* Sensitivity 当按下此按键的时候，该输入轴的数值从默认值以Sensitivity的速度向最大值增加，可视为Gravity属性的相反属性；
* Snap 如果选中，在按下一个按键的同时按下相反方向的按键输入轴数值立刻归零，比如在控制角色移动时，要想同时按下前进键和后退键角色站在原地不动时，可以勾选该属性；
* Invert： 如果选中，Negative Button和Positive Button的效果互换。如果要实现按下前进键时后退效果，可以勾选此项；
* Type 输入轴的输入设备类型，有Key or Mouse Button（j键盘按键、鼠标点击的等）、Mouse Movement（鼠标移动）、Joystick Axis（摇杆控制）；
* Axis： 外设的输入轴，有x控制轴、y控制轴、摇杆及滚轮轴等；
* Joy Num： 使用的摇杆序号。
关于Gravity和Sensitivity我们来看一个例子：
以水平轴为例，在代码中我们这样写：
using UnityEngine;
using System.Collections;
public class Move : MonoBehaviour {
public int Speed = 10;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
float x = Input.GetAxis("Horizontal");
float y = Input.GetAxis("Vertical");
Debug.Log("x:" + x + ";y:" + y + ".");
}
}
我们按下D键的一瞬间，x值从默认值0逐渐增大，在Sensitivity=10的情况下经过7个Uptate时间（一帧的时间）到达目标值1，在Sensitivity=20的情况下经过4个Uptate时间到达目标值1；在我们松开D键的一瞬间x会以Gravity的速度向0变化。
使用代码监听输入轴
我们会用到Input接口来进行监听。在上面的例子中我们使用GetAxis()方法来获取输入轴的数值，参数为输入轴的名字（在Input窗口中的Name）。Input中还有好多监听方法，每个方法都有不同的用处。
GetAxis()和GetAxisRaw()
二者用法相似，区别在于GetAxis()的返回值是从1到-1之间的数，而GetAxisRaw()的返回值只能是0、1、-1。也就是说相比与GetAxisRaw()，GetAxis()提供了按键按下、按键松开的瞬时值。
GetKey* ()和GetButton* ()
GetButton*()和GetKey*()都要求传入一个String类型的参数，GetKey*()要求该参数是预设的枚举类型参数，在KeyCode.cs中定义；而GetButton*()中形参既可以是KeyCode.cs中定义好的枚举类型参数，也可以使在Input面板中我们自定义的参数Name，所以我们一般使用GetButton* ()。
GetButton* ()主要有GetButton()、GetButtonDown()、GetButtonUp()。在按下Button的那一帧，GetButton()、GetButtonDown()返回值为true。之后在按住Button时，GetButton()返回值为true，GetButtonDown()的返回值为false。在松开Button的那一帧，GetButton()的返回值变为false，GetButtonUp()的返回值变为true。在之后的一帧中，GetButonUp()的返回值变false。
GetMouseButton*()
监听鼠标按键。传入参数为整数0、1、2，分别代表左键、右键、滚轮键。GetMouseButton* ()有GetMouseButtonDown()、GetMouseButton()、GetMouseButtonUp()，其用法和GetButton* ()相似。
GetTouch()
Unity提供了对移动设备监听的接口，包括对触摸屏、加速度计、地理位置的监听。Input类中的GetTouch()用于对触摸屏监听，其返回值为预定义的Touch结构体，代表在屏幕上的一次触摸，该结构组成如下：
一般我们经常会用到Touch里面的phase。phase是TouchPhase类，而TouchPhase是一个枚举类型，定义如下：
public enum TouchPhase
{
// A finger touched the screen.
Began = 0,
// A finger moved on the screen.
Moved = 1,
// A finger is touching the screen but hasn't moved.
Stationary = 2,
// A finger was lifted from the screen. This is the final phase of a touch.
Ended = 3,
// The system cancelled tracking for the touch.
Canceled = 4
}其中，Began表示手指刚刚触摸屏幕（一次Touch的开始）；Moved表示手指在屏幕上移动；Stationary表示手指触摸屏幕且静止不动；Ended表示手指离开屏幕，Touch结束；Canceled表示系统取消了触控跟踪，比如说在触摸过程中用户将脸或者大腿贴在了屏幕上（显然没有哪款游戏是用脸或大腿触屏来控制的）。
Unity圣典给出了一个示例，用户在屏幕上点击，将射出一条光线：
var particle : GameObject;
function Update () {
for (var touch : Touch in Input.touches) {
if (touch.phase == TouchPhase.Began) {
// Construct a ray from the current touch coordinates
//从当前的触摸坐标建一条光线
var ray = Camera.main.ScreenPointToRay (touch.position);
if (Physics.Raycast (ray)) {
// Create a particle if hit
//如果触摸就创建一个例子
Instantiate (particle, transform.position, transform.rotation);
}
}
}
}KeyCode.cs
在GetButton()和GetCode()调用中，需要传入KeyCode.cs中预定义的枚举类型参数。KeyCode.cs中所有枚举参数如下：
| 键值 | 描述 |
|---|---|
| None | Not assigned (never returned as the result of a keystroke). |
| Backspace | The backspace key. |
| Delete | The forward delete key. |
| Tab | The tab key. |
| Clear | The Clear key. |
| Return | Return key. |
| Pause | Pause on PC machines. |
| Escape | Escape key. |
| Space | Space key. |
| Keypad0 | Numeric keypad 0. |
| Keypad1 | Numeric keypad 1. |
| Keypad2 | Numeric keypad 2. |
| Keypad3 | Numeric keypad 3. |
| Keypad4 | Numeric keypad 4. |
| Keypad5 | Numeric keypad 5. |
| Keypad6 | Numeric keypad 6. |
| Keypad7 | Numeric keypad 7. |
| Keypad8 | Numeric keypad 8. |
| Keypad9 | Numeric keypad 9. |
| KeypadPeriod | Numeric keypad ‘.’. |
| KeypadDivide | Numeric keypad ‘/’. |
| KeypadMultiply | Numeric keypad ‘*’. |
| KeypadMinus | Numeric keypad ‘-‘. |
| KeypadPlus | Numeric keypad ‘+’. |
| KeypadEnter | Numeric keypad enter. |
| KeypadEquals | Numeric keypad ‘=’. |
| UpArrow | Up arrow key. |
| DownArrow | Down arrow key. |
| RightArrow | Right arrow key. |
| LeftArrow | Left arrow key. |
| Insert | Insert key key. |
| Home | Home key. |
| End | End key. |
| PageUp | Page up. |
| PageDown | Page down. |
| F1 | F1 function key. |
| F2 | F2 function key. |
| F3 | F3 function key. |
| F4 | F4 function key. |
| F5 | F5 function key. |
| F6 | F6 function key. |
| F7 | F7 function key. |
| F8 | F8 function key. |
| F9 | F9 function key. |
| F10 | F10 function key. |
| F11 | F11 function key. |
| F12 | F12 function key. |
| F13 | F13 function key. |
| F14 | F14 function key. |
| F15 | F15 function key. |
| Alpha0 | The ‘0’ key on the top of the alphanumeric keyboard. |
| Alpha1 | The ‘1’ key on the top of the alphanumeric keyboard. |
| Alpha2 | The ‘2’ key on the top of the alphanumeric keyboard. |
| Alpha3 | The ‘3’ key on the top of the alphanumeric keyboard. |
| Alpha4 | The ‘4’ key on the top of the alphanumeric keyboard. |
| Alpha5 | The ‘5’ key on the top of the alphanumeric keyboard. |
| Alpha6 | The ‘6’ key on the top of the alphanumeric keyboard. |
| Alpha7 | The ‘7’ key on the top of the alphanumeric keyboard. |
| Alpha8 | The ‘8’ key on the top of the alphanumeric keyboard. |
| Alpha9 | The ‘9’ key on the top of the alphanumeric keyboard. |
| Exclaim | Exclamation mark key ‘!’. |
| DoubleQuote | Double quote key ‘”’. |
| Hash | Hash key ‘#’. |
| Dollar | Dollar sign key ‘$’. |
| Ampersand | Ampersand key ‘&’. |
| Quote | Quote key ‘. |
| LeftParen | Left Parenthesis key ‘(‘. |
| RightParen | Right Parenthesis key ‘)’. |
| Asterisk | Asterisk key ‘*’. |
| Plus | Plus key ‘+’. |
| Comma | Comma ‘,’ key. |
| Minus | Minus ‘-’ key. |
| Period | Period ‘.’ key. |
| Slash | Slash ‘/’ key. |
| Colon | Colon ‘:’ key. |
| Semicolon | Semicolon ‘;’ key. |
| Less | Less than ‘<’ key. |
| Equals | Equals ‘=’ key. |
| Greater | Greater than ‘>’ key. |
| Question | Question mark ‘?’ key. |
| At | At key ‘@’. |
| LeftBracket | Left square bracket key ‘[‘. |
| Backslash | Backslash key ‘\’. |
| RightBracket | Right square bracket key ‘]’. |
| Caret | Caret key ‘^’. |
| Underscore | Underscore ‘_’ key. |
| BackQuote | Back quote key ‘`’. |
| A | ‘a’ key. |
| B | ‘b’ key. |
| C | ‘c’ key. |
| D | ‘d’ key. |
| E | ‘e’ key. |
| F | ‘f’ key. |
| G | ‘g’ key. |
| H | ‘h’ key. |
| I | ‘i’ key. |
| J | ‘j’ key. |
| K | ‘k’ key. |
| L | ‘l’ key. |
| M | ‘m’ key. |
| N | ‘n’ key. |
| O | ‘o’ key. |
| P | ‘p’ key. |
| Q | ‘q’ key. |
| R | ‘r’ key. |
| S | ’s’ key. |
| T | ‘t’ key. |
| U | ‘u’ key. |
| V | ‘v’ key. |
| W | ‘w’ key. |
| X | ‘x’ key. |
| Y | ‘y’ key. |
| Z | ‘z’ key. |
| Numlock | Numlock key. |
| CapsLock | Capslock key. |
| ScrollLock | Scroll lock key. |
| RightShift | Right shift key. |
| LeftShift | Left shift key. |
| RightControl | Right Control key. |
| LeftControl | Left Control key. |
| RightAlt | Right Alt key. |
| LeftAlt | Left Alt key. |
| LeftCommand | Left Command key. |
| LeftApple | Left Command key. |
| LeftWindows | Left Windows key. |
| RightCommand | Right Command key. |
| RightApple | Right Command key. |
| RightWindows | Right Windows key. |
| AltGr | Alt Gr key. |
| Help | Help key. |
| Print key. | |
| SysReq | Sys Req key. |
| Break | Break key. |
| Menu | Menu key. |
| Mouse0 | The Left (or primary) mouse button. |
| Mouse1 | Right mouse button (or secondary mouse button). |
| Mouse2 | Middle mouse button (or third button). |
| Mouse3 | Additional (fourth) mouse button. |
| Mouse4 | Additional (fifth) mouse button. |
| Mouse5 | Additional (or sixth) mouse button. |
| Mouse6 | Additional (or seventh) mouse button. |
| JoystickButton0 | Button 0 on any joystick. |
| JoystickButton1 | Button 1 on any joystick. |
| JoystickButton2 | Button 2 on any joystick. |
| JoystickButton3 | Button 3 on any joystick. |
| JoystickButton4 | Button 4 on any joystick. |
| JoystickButton5 | Button 5 on any joystick. |
| JoystickButton6 | Button 6 on any joystick. |
| JoystickButton7 | Button 7 on any joystick. |
| JoystickButton8 | Button 8 on any joystick. |
| JoystickButton9 | Button 9 on any joystick. |
| JoystickButton10 | Button 10 on any joystick. |
| JoystickButton11 | Button 11 on any joystick. |
| JoystickButton12 | Button 12 on any joystick. |
| JoystickButton13 | Button 13 on any joystick. |
| JoystickButton14 | Button 14 on any joystick. |
| JoystickButton15 | Button 15 on any joystick. |
| JoystickButton16 | Button 16 on any joystick. |
| JoystickButton17 | Button 17 on any joystick. |
| JoystickButton18 | Button 18 on any joystick. |
| JoystickButton19 | Button 19 on any joystick. |
| Joystick1Button0 | Button 0 on first joystick. |
| Joystick1Button1 | Button 1 on first joystick. |
| Joystick1Button2 | Button 2 on first joystick. |
| Joystick1Button3 | Button 3 on first joystick. |
| Joystick1Button4 | Button 4 on first joystick. |
| Joystick1Button5 | Button 5 on first joystick. |
| Joystick1Button6 | Button 6 on first joystick. |
| Joystick1Button7 | Button 7 on first joystick. |
| Joystick1Button8 | Button 8 on first joystick. |
| Joystick1Button9 | Button 9 on first joystick. |
| Joystick1Button10 | Button 10 on first joystick. |
| Joystick1Button11 | Button 11 on first joystick. |
| Joystick1Button12 | Button 12 on first joystick. |
| Joystick1Button13 | Button 13 on first joystick. |
| Joystick1Button14 | Button 14 on first joystick. |
| Joystick1Button15 | Button 15 on first joystick. |
| Joystick1Button16 | Button 16 on first joystick. |
| Joystick1Button17 | Button 17 on first joystick. |
| Joystick1Button18 | Button 18 on first joystick. |
| Joystick1Button19 | Button 19 on first joystick. |
| Joystick2Button0 | Button 0 on second joystick. |
| Joystick2Button1 | Button 1 on second joystick. |
| Joystick2Button2 | Button 2 on second joystick. |
| Joystick2Button3 | Button 3 on second joystick. |
| Joystick2Button4 | Button 4 on second joystick. |
| Joystick2Button5 | Button 5 on second joystick. |
| Joystick2Button6 | Button 6 on second joystick. |
| Joystick2Button7 | Button 7 on second joystick. |
| Joystick2Button8 | Button 8 on second joystick. |
| Joystick2Button9 | Button 9 on second joystick. |
| Joystick2Button10 | Button 10 on second joystick. |
| Joystick2Button11 | Button 11 on second joystick. |
| Joystick2Button12 | Button 12 on second joystick. |
| Joystick2Button13 | Button 13 on second joystick. |
| Joystick2Button14 | Button 14 on second joystick. |
| Joystick2Button15 | Button 15 on second joystick. |
| Joystick2Button16 | Button 16 on second joystick. |
| Joystick2Button17 | Button 17 on second joystick. |
| Joystick2Button18 | Button 18 on second joystick. |
| Joystick2Button19 | Button 19 on second joystick. |
| Joystick3Button0 | Button 0 on third joystick. |
| Joystick3Button1 | Button 1 on third joystick. |
| Joystick3Button2 | Button 2 on third joystick. |
| Joystick3Button3 | Button 3 on third joystick. |
| Joystick3Button4 | Button 4 on third joystick. |
| Joystick3Button5 | Button 5 on third joystick. |
| Joystick3Button6 | Button 6 on third joystick. |
| Joystick3Button7 | Button 7 on third joystick. |
| Joystick3Button8 | Button 8 on third joystick. |
| Joystick3Button9 | Button 9 on third joystick. |
| Joystick3Button10 | Button 10 on third joystick. |
| Joystick3Button11 | Button 11 on third joystick. |
| Joystick3Button12 | Button 12 on third joystick. |
| Joystick3Button13 | Button 13 on third joystick. |
| Joystick3Button14 | Button 14 on third joystick. |
| Joystick3Button15 | Button 15 on third joystick. |
| Joystick3Button16 | Button 16 on third joystick. |
| Joystick3Button17 | Button 17 on third joystick. |
| Joystick3Button18 | Button 18 on third joystick. |
| Joystick3Button19 | Button 19 on third joystick. |
| Joystick4Button0 | Button 0 on forth joystick. |
| Joystick4Button1 | Button 1 on forth joystick. |
| Joystick4Button2 | Button 2 on forth joystick. |
| Joystick4Button3 | Button 3 on forth joystick. |
| Joystick4Button4 | Button 4 on forth joystick. |
| Joystick4Button5 | Button 5 on forth joystick. |
| Joystick4Button6 | Button 6 on forth joystick. |
| Joystick4Button7 | Button 7 on forth joystick. |
| Joystick4Button8 | Button 8 on forth joystick. |
| Joystick4Button9 | Button 9 on forth joystick. |
| Joystick4Button10 | Button 10 on forth joystick. |
| Joystick4Button11 | Button 11 on forth joystick. |
| Joystick4Button12 | Button 12 on forth joystick. |
| Joystick4Button13 | Button 13 on forth joystick. |
| Joystick4Button14 | Button 14 on forth joystick. |
| Joystick4Button15 | Button 15 on forth joystick. |
| Joystick4Button16 | Button 16 on forth joystick. |
| Joystick4Button17 | Button 17 on forth joystick. |
| Joystick4Button18 | Button 18 on forth joystick. |
| Joystick4Button19 | Button 19 on forth joystick. |
| Joystick5Button0 | Button 0 on fifth joystick. |
| Joystick5Button1 | Button 1 on fifth joystick. |
| Joystick5Button2 | Button 2 on fifth joystick. |
| Joystick5Button3 | Button 3 on fifth joystick. |
| Joystick5Button4 | Button 4 on fifth joystick. |
| Joystick5Button5 | Button 5 on fifth joystick. |
| Joystick5Button6 | Button 6 on fifth joystick. |
| Joystick5Button7 | Button 7 on fifth joystick. |
| Joystick5Button8 | Button 8 on fifth joystick. |
| Joystick5Button9 | Button 9 on fifth joystick. |
| Joystick5Button10 | Button 10 on fifth joystick. |
| Joystick5Button11 | Button 11 on fifth joystick. |
| Joystick5Button12 | Button 12 on fifth joystick. |
| Joystick5Button13 | Button 13 on fifth joystick. |
| Joystick5Button14 | Button 14 on fifth joystick. |
| Joystick5Button15 | Button 15 on fifth joystick. |
| Joystick5Button16 | Button 16 on fifth joystick. |
| Joystick5Button17 | Button 17 on fifth joystick. |
| Joystick5Button18 | Button 18 on fifth joystick. |
| Joystick5Button19 | Button 19 on fifth joystick. |
| Joystick6Button0 | Button 0 on sixth joystick. |
| Joystick6Button1 | Button 1 on sixth joystick. |
| Joystick6Button2 | Button 2 on sixth joystick. |
| Joystick6Button3 | Button 3 on sixth joystick. |
| Joystick6Button4 | Button 4 on sixth joystick. |
| Joystick6Button5 | Button 5 on sixth joystick. |
| Joystick6Button6 | Button 6 on sixth joystick. |
| Joystick6Button7 | Button 7 on sixth joystick. |
| Joystick6Button8 | Button 8 on sixth joystick. |
| Joystick6Button9 | Button 9 on sixth joystick. |
| Joystick6Button10 | Button 10 on sixth joystick. |
| Joystick6Button11 | Button 11 on sixth joystick. |
| Joystick6Button12 | Button 12 on sixth joystick. |
| Joystick6Button13 | Button 13 on sixth joystick. |
| Joystick6Button14 | Button 14 on sixth joystick. |
| Joystick6Button15 | Button 15 on sixth joystick. |
| Joystick6Button16 | Button 16 on sixth joystick. |
| Joystick6Button17 | Button 17 on sixth joystick. |
| Joystick6Button18 | Button 18 on sixth joystick. |
| Joystick6Button19 | Button 19 on sixth joystick. |
| Joystick7Button0 | Button 0 on seventh joystick. |
| Joystick7Button1 | Button 1 on seventh joystick. |
| Joystick7Button2 | Button 2 on seventh joystick. |
| Joystick7Button3 | Button 3 on seventh joystick. |
| Joystick7Button4 | Button 4 on seventh joystick. |
| Joystick7Button5 | Button 5 on seventh joystick. |
| Joystick7Button6 | Button 6 on seventh joystick. |
| Joystick7Button7 | Button 7 on seventh joystick. |
| Joystick7Button8 | Button 8 on seventh joystick. |
| Joystick7Button9 | Button 9 on seventh joystick. |
| Joystick7Button10 | Button 10 on seventh joystick. |
| Joystick7Button11 | Button 11 on seventh joystick. |
| Joystick7Button12 | Button 12 on seventh joystick. |
| Joystick7Button13 | Button 13 on seventh joystick. |
| Joystick7Button14 | Button 14 on seventh joystick. |
| Joystick7Button15 | Button 15 on seventh joystick. |
| Joystick7Button16 | Button 16 on seventh joystick. |
| Joystick7Button17 | Button 17 on seventh joystick. |
| Joystick7Button18 | Button 18 on seventh joystick. |
| Joystick7Button19 | Button 19 on seventh joystick. |
| Joystick8Button0 | Button 0 on eighth joystick. |
| Joystick8Button1 | Button 1 on eighth joystick. |
| Joystick8Button2 | Button 2 on eighth joystick. |
| Joystick8Button3 | Button 3 on eighth joystick. |
| Joystick8Button4 | Button 4 on eighth joystick. |
| Joystick8Button5 | Button 5 on eighth joystick. |
| Joystick8Button6 | Button 6 on eighth joystick. |
| Joystick8Button7 | Button 7 on eighth joystick. |
| Joystick8Button8 | Button 8 on eighth joystick. |
| Joystick8Button9 | Button 9 on eighth joystick. |
| Joystick8Button10 | Button 10 on eighth joystick. |
| Joystick8Button11 | Button 11 on eighth joystick. |
| Joystick8Button12 | Button 12 on eighth joystick. |
| Joystick8Button13 | Button 13 on eighth joystick. |
| Joystick8Button14 | Button 14 on eighth joystick. |
| Joystick8Button15 | Button 15 on eighth joystick. |
| Joystick8Button16 | Button 16 on eighth joystick. |
| Joystick8Button17 | Button 17 on eighth joystick. |
| Joystick8Button18 | Button 18 on eighth joystick. |
| Joystick8Button19 | Button 19 on eighth joystick. |