鼠标事件有这么多种，手柄的可以忽视，Sdl.SDL_KEYDOWN，Sdl.SDL_KEYUP，Sdl.SDL_MOUSEMOTION，Sdl.SDL_MOUSEBUTTONDOWN，Sdl.SDL_MOUSEBUTTONUP应该是常用的。
public enum EventTypes
{
/// <summary>
/// No event
/// </summary>
None = Sdl.SDL_NOEVENT,
/// <summary>
/// Active event
/// </summary>
ActiveEvent = Sdl.SDL_ACTIVEEVENT,
/// <summary>
/// Key down event
/// </summary>
KeyDown = Sdl.SDL_KEYDOWN,
/// <summary>
/// Key up event
/// </summary>
KeyUp = Sdl.SDL_KEYUP,
/// <summary>
/// Mouse Motion event
/// </summary>
MouseMotion = Sdl.SDL_MOUSEMOTION,
/// <summary>
/// Mouse button down event
/// </summary>
MouseButtonDown = Sdl.SDL_MOUSEBUTTONDOWN,
/// <summary>
/// Mouse button up event
/// </summary>
MouseButtonUp = Sdl.SDL_MOUSEBUTTONUP,
/// <summary>
/// Joystick Axis motion event
/// </summary>
JoystickAxisMotion = Sdl.SDL_JOYAXISMOTION,
/// <summary>
/// Joystick ball motion event
/// </summary>
JoystickBallMotion = Sdl.SDL_JOYBALLMOTION,
/// <summary>
/// Joystick hat motion event
/// </summary>
JoystickHatMotion = Sdl.SDL_JOYHATMOTION,
/// <summary>
/// Joystick button down event
/// </summary>
JoystickButtonDown = Sdl.SDL_JOYBUTTONDOWN,
/// <summary>
/// joystick button up event
/// </summary>
JoystickButtonUp = Sdl.SDL_JOYBUTTONUP,
/// <summary>
/// Video resize event
/// </summary>
VideoResize = Sdl.SDL_VIDEORESIZE,
/// <summary>
/// Video expose event
/// </summary>
VideoExpose = Sdl.SDL_VIDEOEXPOSE,
/// <summary>
/// Quit event
/// </summary>
Quit = Sdl.SDL_QUIT,
/// <summary>
/// Window manager event
/// </summary>
WindowManagerEvent = Sdl.SDL_SYSWMEVENT,
/// <summary>
/// user-defined event
/// </summary>
UserEvent = Sdl.SDL_USEREVENT
}
鼠标点击后的button：
public enum MouseButton
{
/// <summary>
/// None
/// </summary>
None = ,
/// <summary>
/// Primary button. Typically the left button
/// </summary>
PrimaryButton = Sdl.SDL_BUTTON_LEFT,
/// <summary>
/// Secondary button. typically the right button
/// </summary>
SecondaryButton = Sdl.SDL_BUTTON_RIGHT,
/// <summary>
/// Middle button
/// </summary>
MiddleButton = Sdl.SDL_BUTTON_MIDDLE,
/// <summary>
/// Wheel up
/// </summary>
WheelUp = Sdl.SDL_BUTTON_WHEELUP,
/// <summary>
/// Wheel down
/// </summary>
WheelDown = Sdl.SDL_BUTTON_WHEELDOWN
}
常用的代码写法
while (!quit) //建立事件主循环
{
while (Sdl.SDL_PollEvent(out ev) == )//从队列里取出事件
{
Sdl.SDL_WaitEvent(out ev); //必须等待
if (ev.type == Sdl.SDL_MOUSEBUTTONDOWN)
{
if (ev.button.button == Sdl.SDL_BUTTON_LEFT)
{
MouseDown(ev.button);
}
else
if (ev.button.button ==Sdl.SDL_BUTTON_RIGHT)
{
}
}
else
if (ev.type == Sdl.SDL_MOUSEMOTION)
{
MouseMove (ev.button);
}
else
if (ev.type == Sdl.SDL_MOUSEBUTTONUP)
{
if (ev.button.button ==Sdl.SDL_BUTTON_LEFT)
{
MouseUp (ev.button);
}
}
else
if (ev.type ==Sdl.SDL_VIDEORESIZE)
{
}
else
if (ev.type ==Sdl.SDL_QUIT)
{
quit = true;
break;
}
}
}
在处理SDL的事件有两种模式，一种是等待 SDL_WaitEvent,另一种是轮询SDL_PollEvent
目前，在网上可以查到的文章，大多数都使用了轮询，还有人指出等待有时会导致事件处理延迟。但是我在实际coding中，使用SDL_PollEvent，一运行就风扇不停的转，用top看了下，cpu占用到了99%。
实际上，使用wait已经足够，我不大清楚这种轮询机制在什么时候会用到。
以下是一个SDL_PollEvent的原型。分析一下这段程序：
在while(quit!=1)这个循环中，如果没有发生任何事件，quit始终为0,那么在用户没有任何操作的情况下，这里会无限循环，直到event发生，进入了SDL_PollEvent的循环中。
这就导致了cpu占用率达到了100%. 因此，这种方法是不可取的。
在外层有循环时，SDL_PollEvent论询是不能用的。如果单独使用，用户无操作的时候，又无法进入处理事件的部分。实在不能明白它有什么用。
我考虑是不是这个应该用在非实时处理的时候，比如while(quit!=1)循环中嵌入一个sleep(1)之类。
void WaitKeyboard(SubWin sw){
int quit = ;
SDL_Event event;
KEYBOARDMODE kmode = COMMAND;
while(quit!=){
// printf ( "waiting for keyboard action\n" );
while( SDL_PollEvent(&event)){
printf ( "WaitKeyboard: caught keyboard %x\n", event.key.keysym.sym );
switch (event.type){
case SDL_KEYDOWN:
printf ( "tracking keydown\n" );
kmode = TrackKeyDown(sw, event.key.keysym.sym, kmode);
break;
case SDL_QUIT:
printf("Stop !\n");
quit = ;
break;
}
}
}
endSDL();
}
接下来是SDL_WaitEvent的原型
在while(quit!=1)的循环中，由于SDL_WaitEvent语句，在用户未发生任何操作前，程序处于等待状态，不会进入下一次循环，这样就避免了cpu占用的问题。
这样的做法才是正确处理SDL事件的方法。
void WaitKeyboard(SubWin sw){
int quit = ;
SDL_Event event;
KEYBOARDMODE kmode = COMMAND;
while(quit!=){
// printf ( "waiting for keyboard action\n" );
// while( SDL_PollEvent(&event)){
SDL_WaitEvent(&event);
printf ( "WaitKeyboard: caught keyboard %x\n", event.key.keysym.sym );
switch (event.type){
case SDL_KEYDOWN:
printf ( "tracking keydown\n" );
kmode = TrackKeyDown(sw, event.key.keysym.sym, kmode);
break;
case SDL_QUIT:
printf("stop !\n");
quit = ;
break;
}
}
endSDL();
}
http://blog.chinaunix.net/uid-26456800-id-3337795.html