我已经开始使用XNA Framework编写游戏并遇到了一些我不知道如何正确解决的简单问题。
我正在使用Texture2D显示菜单并使用键盘（或游戏手柄）我更改了所选的菜单项。我的问题是用于在菜单项之间切换的当前函数太快了。我可能会单击向下按钮，它将关闭5或6个菜单项（由于Update（）被多次调用，因此更新所选项目。）
ex.
(> indicate selected)
> MenuItem1
MenuItem2
MenuItem3
MenuItem4
MenuItem5
I press the down key for just a second), then I have this state:
MenuItem1
MenuItem2
MenuItem3
> MenuItem4
MenuItem5
What I want is (until I press the key again)
MenuItem1
> MenuItem2
MenuItem3
MenuItem4
MenuItem5
我正在寻找的方法是让玩家多次点击向上/向下键以便从一个菜单项转到另一个菜单项，或者在进入下一个菜单项之前有一些最短的等待时间菜单项。
答案 0 :(得分：26)
实现此目的的最佳方法是从刚刚通过的更新语句中缓存键盘/游戏手柄状态。
KeyboardState oldState;
...
var newState = Keyboard.GetState();
if (newState.IsKeyDown(Keys.Down) && !oldState.IsKeyDown(Keys.Down))
{
// the player just pressed down
}
else if (newState.IsKeyDown(Keys.Down) && oldState.IsKeyDown(Keys.Down))
{
// the player is holding the key down
}
else if (!newState.IsKeyDown(Keys.Down) && oldState.IsKeyDown(Keys.Down))
{
// the player was holding the key down, but has just let it go
}
oldState = newState;
在你的情况下，你可能只想在上面第一种情况下“向下”移动，只需按下按键。
答案 1 :(得分：18)
我已经构建了一个（大）类，它可以帮助解决任何和所有XNA输入相关的任务，它可以让您轻松应对。
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;
namespace YourNamespaceHere
{
/// <summary>
/// an enum of all available mouse buttons.
/// </summary>
public enum MouseButtons
{
LeftButton,
MiddleButton,
RightButton,
ExtraButton1,
ExtraButton2
}
public class InputHelper
{
private GamePadState _lastGamepadState;
private GamePadState _currentGamepadState;
#if (!XBOX)
private KeyboardState _lastKeyboardState;
private KeyboardState _currentKeyboardState;
private MouseState _lastMouseState;
private MouseState _currentMouseState;
#endif
private PlayerIndex _index = PlayerIndex.One;
private bool refreshData = false;
/// <summary>
/// Fetches the latest input states.
/// </summary>
public void Update()
{
if (!refreshData)
refreshData = true;
if (_lastGamepadState == null && _currentGamepadState == null)
{
_lastGamepadState = _currentGamepadState = GamePad.GetState(_index);
}
else
{
_lastGamepadState = _currentGamepadState;
_currentGamepadState = GamePad.GetState(_index);
}
#if (!XBOX)
if (_lastKeyboardState == null && _currentKeyboardState == null)
{
_lastKeyboardState = _currentKeyboardState = Keyboard.GetState();
}
else
{
_lastKeyboardState = _currentKeyboardState;
_currentKeyboardState = Keyboard.GetState();
}
if (_lastMouseState == null && _currentMouseState == null)
{
_lastMouseState = _currentMouseState = Mouse.GetState();
}
else
{
_lastMouseState = _currentMouseState;
_currentMouseState = Mouse.GetState();
}
#endif
}
/// <summary>
/// The previous state of the gamepad.
/// Exposed only for convenience.
/// </summary>
public GamePadState LastGamepadState
{
get { return _lastGamepadState; }
}
/// <summary>
/// the current state of the gamepad.
/// Exposed only for convenience.
/// </summary>
public GamePadState CurrentGamepadState
{
get { return _currentGamepadState; }
}
/// <summary>
/// the index that is used to poll the gamepad.
/// </summary>
public PlayerIndex Index
{
get { return _index; }
set {
_index = value;
if (refreshData)
{
Update();
Update();
}
}
}
#if (!XBOX)
/// <summary>
/// The previous keyboard state.
/// Exposed only for convenience.
/// </summary>
public KeyboardState LastKeyboardState
{
get { return _lastKeyboardState; }
}
/// <summary>
/// The current state of the keyboard.
/// Exposed only for convenience.
/// </summary>
public KeyboardState CurrentKeyboardState
{
get { return _currentKeyboardState; }
}
/// <summary>
/// The previous mouse state.
/// Exposed only for convenience.
/// </summary>
public MouseState LastMouseState
{
get { return _lastMouseState; }
}
/// <summary>
/// The current state of the mouse.
/// Exposed only for convenience.
/// </summary>
public MouseState CurrentMouseState
{
get { return _currentMouseState; }
}
#endif
/// <summary>
/// The current position of the left stick.
/// Y is automatically reversed for you.
/// </summary>
public Vector2 LeftStickPosition
{
get
{
return new Vector2(
_currentGamepadState.ThumbSticks.Left.X,
-CurrentGamepadState.ThumbSticks.Left.Y);
}
}
/// <summary>
/// The current position of the right stick.
/// Y is automatically reversed for you.
/// </summary>
public Vector2 RightStickPosition
{
get
{
return new Vector2(
_currentGamepadState.ThumbSticks.Right.X,
-_currentGamepadState.ThumbSticks.Right.Y);
}
}
/// <summary>
/// The current velocity of the left stick.
/// Y is automatically reversed for you.
/// expressed as:
/// current stick position - last stick position.
/// </summary>
public Vector2 LeftStickVelocity
{
get
{
Vector2 temp =
_currentGamepadState.ThumbSticks.Left -
_lastGamepadState.ThumbSticks.Left;
return new Vector2(temp.X, -temp.Y);
}
}
/// <summary>
/// The current velocity of the right stick.
/// Y is automatically reversed for you.
/// expressed as:
/// current stick position - last stick position.
/// </summary>
public Vector2 RightStickVelocity
{
get
{
Vector2 temp =
_currentGamepadState.ThumbSticks.Right -
_lastGamepadState.ThumbSticks.Right;
return new Vector2(temp.X, -temp.Y);
}
}
/// <summary>
/// the current position of the left trigger.
/// </summary>
public float LeftTriggerPosition
{
get { return _currentGamepadState.Triggers.Left; }
}
/// <summary>
/// the current position of the right trigger.
/// </summary>
public float RightTriggerPosition
{
get { return _currentGamepadState.Triggers.Right; }
}
/// <summary>
/// the velocity of the left trigger.
/// expressed as:
/// current trigger position - last trigger position.
/// </summary>
public float LeftTriggerVelocity
{
get
{
return
_currentGamepadState.Triggers.Left -
_lastGamepadState.Triggers.Left;
}
}
/// <summary>
/// the velocity of the right trigger.
/// expressed as:
/// current trigger position - last trigger position.
/// </summary>
public float RightTriggerVelocity
{
get
{
return _currentGamepadState.Triggers.Right -
_lastGamepadState.Triggers.Right;
}
}
#if (!XBOX)
/// <summary>
/// the current mouse position.
/// </summary>
public Vector2 MousePosition
{
get { return new Vector2(_currentMouseState.X, _currentMouseState.Y); }
}
/// <summary>
/// the current mouse velocity.
/// Expressed as:
/// current mouse position - last mouse position.
/// </summary>
public Vector2 MouseVelocity
{
get
{
return (
new Vector2(_currentMouseState.X, _currentMouseState.Y) -
new Vector2(_lastMouseState.X, _lastMouseState.Y)
);
}
}
/// <summary>
/// the current mouse scroll wheel position.
/// See the Mouse's ScrollWheel property for details.
/// </summary>
public float MouseScrollWheelPosition
{
get
{
return _currentMouseState.ScrollWheelValue;
}
}
/// <summary>
/// the mouse scroll wheel velocity.
/// Expressed as:
/// current scroll wheel position -
/// the last scroll wheel position.
/// </summary>
public float MouseScrollWheelVelocity
{
get
{
return (_currentMouseState.ScrollWheelValue - _lastMouseState.ScrollWheelValue);
}
}
#endif
/// <summary>
/// Used for debug purposes.
/// Indicates if the user wants to exit immediately.
/// </summary>
public bool ExitRequested
{
#if (!XBOX)
get
{
return (
(IsCurPress(Buttons.Start) &&
IsCurPress(Buttons.Back)) ||
IsCurPress(Keys.Escape));
}
#else
get { return (IsCurPress(Buttons.Start) && IsCurPress(Buttons.Back)); }
#endif
}
/// <summary>
/// Checks if the requested button is a new press.
/// </summary>
/// <param name="button">
/// The button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is being
/// pressed in the current state but not the last state.
/// </returns>
public bool IsNewPress(Buttons button)
{
return (
_lastGamepadState.IsButtonUp(button) &&
_currentGamepadState.IsButtonDown(button));
}
/// <summary>
/// Checks if the requested button is a current press.
/// </summary>
/// <param name="button">
/// the button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(Buttons button)
{
return (
_lastGamepadState.IsButtonDown(button) &&
_currentGamepadState.IsButtonDown(button));
}
/// <summary>
/// Checks if the requested button is an old press.
/// </summary>
/// <param name="button">
/// the button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is not being
/// pressed in the current state and is being pressed in the last state.
/// </returns>
public bool IsOldPress(Buttons button)
{
return (
_lastGamepadState.IsButtonDown(button) &&
_currentGamepadState.IsButtonUp(button));
}
#if (!XBOX)
/// <summary>
/// Checks if the requested key is a new press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool that indicates whether the selected key is being
/// pressed in the current state and not in the last state.
/// </returns>
public bool IsNewPress(Keys key)
{
return (
_lastKeyboardState.IsKeyUp(key) &&
_currentKeyboardState.IsKeyDown(key));
}
/// <summary>
/// Checks if the requested key is a current press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool that indicates whether the selected key is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(Keys key)
{
return (
_lastKeyboardState.IsKeyDown(key) &&
_currentKeyboardState.IsKeyDown(key));
}
/// <summary>
/// Checks if the requested button is an old press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool indicating whether the selectde button is not being
/// pressed in the current state and being pressed in the last state.
/// </returns>
public bool IsOldPress(Keys key)
{
return (
_lastKeyboardState.IsKeyDown(key) &&
_currentKeyboardState.IsKeyUp(key));
}
/// <summary>
/// Checks if the requested mosue button is a new press.
/// </summary>
/// <param name="button">
/// teh mouse button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is being
/// pressed in the current state but not in the last state.
/// </returns>
public bool IsNewPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Released &&
_currentMouseState.LeftButton == ButtonState.Pressed);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Released &&
_currentMouseState.MiddleButton == ButtonState.Pressed);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Released &&
_currentMouseState.RightButton == ButtonState.Pressed);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Released &&
_currentMouseState.XButton1 == ButtonState.Pressed);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Released &&
_currentMouseState.XButton2 == ButtonState.Pressed);
default:
return false;
}
}
/// <summary>
/// Checks if the requested mosue button is a current press.
/// </summary>
/// <param name="button">
/// the mouse button to be checked.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Pressed &&
_currentMouseState.LeftButton == ButtonState.Pressed);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Pressed &&
_currentMouseState.MiddleButton == ButtonState.Pressed);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Pressed &&
_currentMouseState.RightButton == ButtonState.Pressed);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Pressed &&
_currentMouseState.XButton1 == ButtonState.Pressed);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Pressed &&
_currentMouseState.XButton2 == ButtonState.Pressed);
default:
return false;
}
}
/// <summary>
/// Checks if the requested mosue button is an old press.
/// </summary>
/// <param name="button">
/// the mouse button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is not being
/// pressed in the current state and is being pressed in the old state.
/// </returns>
public bool IsOldPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Pressed &&
_currentMouseState.LeftButton == ButtonState.Released);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Pressed &&
_currentMouseState.MiddleButton == ButtonState.Released);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Pressed &&
_currentMouseState.RightButton == ButtonState.Released);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Pressed &&
_currentMouseState.XButton1 == ButtonState.Released);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Pressed &&
_currentMouseState.XButton2 == ButtonState.Released);
default:
return false;
}
}
#endif
}
}
只需将其复制到一个单独的类fie中并将其移动到命名空间，然后声明一个（inputHelper变量），在initialiaze部分初始化它，并在更新逻辑之前调用updateHelper.Update（）。然后，只要您需要与输入相关的内容，只需使用InputHelper！例如，在您的情况下，您将使用InputHelper.IsNewPress（[此处输入按钮/键的类型]）来检查是否要向下或向上移动菜单项。对于此示例：inputHelper.IsNewPress（Keys.Down）
答案 2 :(得分：6)
处理这类事情的一个很好的方法是为你感兴趣的每个键存储一个计数器，如果键是关闭的话你会增加每一帧，如果它关闭则重置为0。
这样做的好处是，您可以测试键的绝对状态（如果计数器非零，键关闭），并且还可以轻松检查是否刚刚按下此帧以显示菜单等（柜台是1）。加上键重复变得容易（计数器％重复延迟为零）。
答案 3 :(得分：3)
如果您的应用程序适用于Windows计算机，我使用此活动驱动的课程取得了巨大的成功：gamedev.net forum post
它可以处理重复启动前的典型按键和短暂停顿，就像Windows应用程序中的普通文本输入一样。还包括鼠标移动/滚轮事件。
您可以订阅活动，例如，使用以下代码：
InputSystem.KeyDown += new KeyEventHandler(KeyDownFunction);
InputSystem.KeyUp += new KeyEventHandler(KeyUpFunction);
然后在方法本身：
void KeyDownFunction(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.F)
facepalm();
}
void KeyUpFunction(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.F)
release();
}
......等等。这真是一个很棒的课程。我发现它的灵活性比XNA的默认键盘处理大大提高了。祝你好运！
答案 4 :(得分：1)
我认为以前的答案有点过于复杂，所以我在这里给这个答案......
将下面的KeyPress类复制到一个新文件中，声明KeyPress变量，在Initialize（）方法中初始化它们。从那里你可以做if ([yourkey].IsPressed()) ...
注意：此答案仅适用于键盘输入，但应轻松移植到游戏手柄或任何其他输入。我认为保持不同类型输入的代码分离更好。
public class KeyPress
{
public KeyPress(Keys Key)
{
key = Key;
isHeld = false;
}
public bool IsPressed { get { return isPressed(); } }
public static void Update() { state = Keyboard.GetState(); }
private Keys key;
private bool isHeld;
private static KeyboardState state;
private bool isPressed()
{
if (state.IsKeyDown(key))
{
if (isHeld) return false;
else
{
isHeld = true;
return true;
}
}
else
{
if (isHeld) isHeld = false;
return false;
}
}
}
<强>用法：
// Declare variable
KeyPress escape;
// Initialize()
escape = new KeyPress(Keys.Escape)
// Update()
KeyPress.Update();
if (escape.IsPressed())
...
我可能错了，但我认为我的答案在资源方面比接受的答案更容易，而且更具可读性！
答案 5 :(得分：0)
您可以按最后一个按键（左，右......）的整数值时间存储，如果此时间大于某个限制，您可以轮询新按下的按键。但是这只能用于菜单，因为在游戏中你需要立即获得这些信息。
答案 6 :(得分：0)
好的，我已经明白了。首先，我添加了一个
private Keys keyPressed = Keys.None;
在我的Update（）方法中，我执行以下操作：
KeyboardState keyboardState = Keyboard.GetState();
if (keyboardState.IsKeyUp(keyPressed))
{
keyPressed = Keys.None;
}
if (keyboardState.IsKeyDown(keyPressed))
{
return;
}
// Some additionnal stuff is done according to direction
if (keyboardState.IsKeyDown(Keys.Up))
{
keyPressed = Keys.Up;
}
else if (keyboardState.IsKeyDown(Keys.Down))
{
keyPressed = Keys.Down;
}
似乎工作正常。
答案 7 :(得分：0)
你还可以做一个结合KyeUp和KeyDown的功能，它告诉你按键被按下一次，只有一次更新循环，这样它只有在你每次再按一次键时才有效。
答案 8 :(得分：0)
我保存了之前更新运行中的GamePadState和KeyboardState。在下一次更新运行中，我检查上次运行时未按下的按钮，但现在按下。然后我保存当前状态。
我把所有这些都包含在一个静态类中，我可以使用它来查询特定按钮和/或获取自上次更新以来按下的按钮列表。这使得同时使用多个键非常容易（在游戏中你肯定需要的东西）并且它可以轻松地扩展到和弦。
答案 9 :(得分：0)
拉涅利，这看起来像什么？我正忙着处理这些更新周期......
... Hrmmm
public static bool CheckKeyPress(Keys key)
{
return keyboardState.IsKeyUp(key) && lastKeyboardState.IsKeyDown(key);
}
SetStates（）是私有的，它在Update（）
中调用private static void SetStates()
{
lastKeyboardState = keyboardState;
keyboardState = Keyboard.GetState();
}
这是更新......
public sealed override void Update(GameTime gameTime)
{
// Called to set the states of the input devices
SetStates();
base.Update(gameTime);
}
我已经尝试添加额外的支票..
if (Xin.CheckKeyPress(Keys.Enter) ||
Xin.CheckButtonPress(Buttons.A))
{
if (Xin.LastKeyboardState != Xin.KeyboardState ||
Xin.LastGamePadState(PlayerIndex.One) != Xin.GamePadState(PlayerIndex.One))
{
似乎没有任何明显的效果 - 我似乎无法放慢菜单确认速度，
答案 10 :(得分：0)
你可以做的就是这样（也会跟踪每一个键）
int[] keyVals;
TimeSpan pressWait = new TimeSpan(0, 0, 1);
Dictionary<Keys, bool> keyDowns = new Dictionary<Keys, bool>();
Dictionary<Keys, DateTime> keyTimes = new Dictionary<Keys, DateTime>();
public ConstructorNameHere
{
keyVals = Enum.GetValues(typeof(Keys)) as int[];
foreach (int k in keyVals)
{
keyDowns.Add((Keys)k, false);
keyTimes.Add((Keys)k, new DateTime()+ new TimeSpan(1,0,0));
}
}
protected override void Update(GameTime gameTime)
{
foreach (int i in keyVals)
{
Keys key = (Keys)i;
switch (key)
{
case Keys.Enter:
keyTimes[key] = (Keyboard.GetState().IsKeyUp(key)) ? ((keyDowns[key]) ? DateTime.Now + pressWait : keyTimes[key]) : keyTimes[key];
keyDowns[key] = (keyTimes[key] > DateTime.Now) ? false : Keyboard.GetState().IsKeyDown(key);
if (keyTimes[key] < DateTime.Now)
{
// Code for what happens when Keys.Enter is pressed goes here.
}
break;
}
}
通过这种方式，您可以检查每个键。您也可以通过创建单独的DateTimes和单独的bool值来为每个键执行此操作。
答案 11 :(得分：0)
我知道这是旧的，但是怎么样： 添加线程安全字典：
private ConcurrentDictionary<Keys, DateTime> _keyBounceDict = new ConcurrentDictionary<Keys, DateTime>();
然后使用此方法跟踪按下的按键并确定是否存在按键反弹：
///////////////////////////////////////////////////////////////////////////////////////////
/// IsNotKeyBounce - determines if a key is bouncing and therefore not valid within
/// a certain "delay" period
///////////////////////////////////////////////////////////////////////////////////////////
private bool IsNotKeyBounce(Keys thekey, double delay)
{
bool OKtoPress = true;
if (_keyBounceDict.ContainsKey(thekey))
{
TimeSpan ts = DateTime.Now - _keyBounceDict[thekey];
if (ts.TotalMilliseconds < _tsKeyBounceTiming)
{
OKtoPress = false;
}
else
{
DateTime dummy;
_keyBounceDict.TryRemove(thekey, out dummy);
}
}
else
{
_keyBounceDict.AddOrUpdate(thekey, DateTime.Now, (key, oldValue) => oldValue);
}
return OKtoPress;
}
以下是我在Update方法中的内容：
if (Keyboard.GetState().IsKeyDown(Keys.W))
{
if (IsNotKeyBounce(Keys.W, 50.0)) _targetNew.Distance *= 1.1f;
}
我使用50毫秒，但您可以使用对您的应用有意义的任何内容或将其绑定到GameTime或其他...