1.问题描述：
在4.1的系统下，调试机器是768*1024的
默认使得在launcher 是，状态栏显示menu键，但是按下menu键时却没有相应界面弹出，
但是原来的机器：1024*600的就没有任何问题
1）查找原因：
launcher代码问题，通过不同的机器对比同样的代码，证明代码没有问题
资源布局问题：强行走1024*600的布局，证明布局没有问题
唯一区别代码尺寸不同，最后只能追查menu键按下的处理过程，最终确认原因。
2）确认问题原因：
menu键按下处理的关键：
文件：
PhoneWindow.java (frameworksasepolicysrccomandroidinternalpolicyimpl)
按键按下后会走到一下的两个文件：
public final boolean onKeyDownPanel(int featureId, KeyEvent event) {
}
public final void onKeyUpPanel(int featureId, KeyEvent event) {
...
openPanel(st, event);
...
}
private void openPanel(PanelFeatureState st, KeyEvent event) {
// System.out.println("Open panel: isOpen=" + st.isOpen);
// Already open, return
if (st.isOpen || isDestroyed()) {
return;
}
// Don't open an options panel for honeycomb apps on xlarge devices.
// (The app should be using an action bar for menu items.)
if (st.featureId == FEATURE_OPTIONS_PANEL) {
Context context = getContext();
Configuration config = context.getResources().getConfiguration();
boolean isXLarge = (config.screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) ==
Configuration.SCREENLAYOUT_SIZE_XLARGE;
boolean isHoneycombApp = context.getApplicationInfo().targetSdkVersion >=
android.os.Build.VERSION_CODES.HONEYCOMB;
if (isXLarge && isHoneycombApp) {
return;
}//这里就是问题的原因
}
...
}
3）//问题分析，条件有两个
isXLarge 和 isHoneycombApp
isXLarge 为真：
boolean isXLarge = (config.screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) ==
Configuration.SCREENLAYOUT_SIZE_XLARGE;
分析：文件：WindowManagerService.java (frameworksaseservicesjavacomandroidserverwm)
private int reduceConfigLayout(int curLayout, int rotation, float density, int dw, int dh) {
...
// configuration. DO NOT CHANGE!
if (longSize < 470) {
// This is shorter than an HVGA normal density screen (which
// is 480 pixels on its long side).
screenLayoutSize = Configuration.SCREENLAYOUT_SIZE_SMALL;
screenLayoutLong = false;
screenLayoutCompatNeeded = false;
} else {
// What size is this screen screen?
if (longSize >= 960 && shortSize >= 720) {
// 1.5xVGA or larger screens at medium density are the point
// at which we consider it to be an extra large screen.
screenLayoutSize = Configuration.SCREENLAYOUT_SIZE_XLARGE;//系统走的是这里，原因
} else if (longSize >= 640 && shortSize >= 480) {
// VGA or larger screens at medium density are the point
// at which we consider it to be a large screen.
screenLayoutSize = Configuration.SCREENLAYOUT_SIZE_LARGE;
} else {
screenLayoutSize = Configuration.SCREENLAYOUT_SIZE_NORMAL;
}
...
}
4）解决方法：在函数中屏蔽掉，问题解决，按menu键后弹出选项：
private void openPanel(PanelFeatureState st, KeyEvent event) {
if (isXLarge && isHoneycombApp) {
;//return;//屏蔽掉
}//这里就是问题的原因
}