程序关闭后，点击dock图标恢复窗口

1.在遵守NSApplicationDelegate的XXXdelegate.h里设置窗口的outlet

在XXXdelegate.m里添加

- (BOOL)applicationShouldHandleReopen:(NSApplication *)sender hasVisibleWindows:(BOOL)flag

{

if (flag) {

return NO;

}

else

{

[window makeKeyAndOrderFront:self];

return YES;

}

}

2.连接outlet NSWindow *window和nib里的窗口，在Interface Builder中，将主窗口的”Release When Closed”选项取消掉。

3.设置NSApplication的委托为XXXdelegate，也就是file‘s ower的outlet delegate设置为XXXdelegate。

其他写法：
http://blog.cnrainbird.com/index.php/2012/10/23/osx_cheng_xu_dian_ji_dock_tu_biao_zhong_xin_dan_chu_chuang_kou/
- (BOOL)applicationShouldHandleReopen:(NSApplication *)theApplication

hasVisibleWindows:(BOOL)flag{

if (!flag){

//主窗口显示

[NSApp activateIgnoringOtherApps:NO];

[self.window makeKeyAndOrderFront:self];

}

return YES;

}
http://hintsforums.macworld.com/showthread.php?t=40039

- (BOOL)applicationShouldHandleReopen:(NSApplication *)theApplication
hasVisibleWindows:(BOOL)flag
{
if (flag) {
return NO;
} else {
[mainWindow orderFront:self];
return YES;
}
}