android4.0 中如何在app 中屏蔽HOME键

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新发现的拦截home 建的办法

/** 拦截HOME/MENU */

sendBroadcast((new Intent("android.intent.action.AgamaECGEnter")));

/** 取消拦截HOME/MENU */

sendBroadcast((new Intent("android.intent.action.AgamaECGLeave")));

以下为转载

近日在研究一个视频锁的功能，即在视频播放界面上设一个锁的功能，当该锁起效后，就会屏蔽back, home, menu三个键的功能。

back 和 menu 键都可以通过 app层的 onKeyDown 和 onKeyUp 函数来拦截。但是 home 键不行。

于是上网查了一下在app层屏蔽 home 键的方法。

主流的方法如下所示。但只在2.2，2.3平台下有效。（下面列举的方法只在android 2.2, 2.3 上有效）

屏蔽Activity, Dialog风格Activity, AlertDialog的Home键功能方法分别是:

1.屏蔽Activity中的Home键功能，只需要在你要屏蔽的activity 中重写 onAttachToWindow() 这个函数就可以了

[java]
@Override
public void onAttachedToWindow() {
    this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);
    super.onAttachedToWindow();
}
    @Override
    public void onAttachedToWindow() {
        this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);
        super.onAttachedToWindow();
    }

2.屏蔽 Dialog风格Activity的Home键功能，也需要在你要屏蔽的activity 中重写 onAttachToWindow() 这个函数，但设置window 的值需要改变为 TYPE_KEYGUARD_DIALOG

[java]
@Override
public void onAttachedToWindow() {
    this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
    super.onAttachedToWindow();
}
    @Override
    public void onAttachedToWindow() {
        this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
        super.onAttachedToWindow();
    }

这里之所以和Activity区分,是因为Dialog风格Activity如果用第一种方法,这个Dialog风格Activity的背景就变成黑色的,而不是透明的.

3.屏蔽AlertDialog的Home键功能

[java]
AlertDialog d = b.create();
d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
AlertDialog d = b.create();
d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);

后面通过上面一篇文章的思路来看 4.0平台的 framework 层的代码，发现在 PhoneWindowManager.java 的 interceptKeyBeforeDispatching 函数中对home键的处理如下：

[java]
if (keyCode == KeyEvent.KEYCODE_HOME) {
    // If we have released the home key, and didn't do anything else
    // while it was pressed, then it is time to go home!
    if (mHomePressed && !down) {
        mHomePressed = false;

..

    }

    // If a system window has focus, then it doesn't make sense
    // right now to interact with applications.
    WindowManager.LayoutParams attrs = win != null ? win.getAttrs() : null;
    if (attrs != null) {
        final int type = attrs.type;
        if (type == WindowManager.LayoutParams.TYPE_KEYGUARD
                || type == WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG) {
            // the "app" is keyguard, so give it the key
            return 0;
        }
        final int typeCount = WINDOW_TYPES_WHERE_HOME_DOESNT_WORK.length;
        for (int i=0; i<typeCount; i++) {
            if (type == WINDOW_TYPES_WHERE_HOME_DOESNT_WORK[i]) {
                // don't do anything, but also don't pass it to the app
                return -1;
            }
        }

        final int flag = attrs.flags;

        if ((flag & WindowManager.LayoutParams.FLAG_HOMEKEY_DISPATCHED) != 0) {
            // the window wants to handle the home key, so dispatch it to it.
            return 0;
        }
    }

    return -1;
        if (keyCode == KeyEvent.KEYCODE_HOME) {
            // If we have released the home key, and didn't do anything else
            // while it was pressed, then it is time to go home!
            if (mHomePressed && !down) {
                mHomePressed = false;

    ......

            }

            // If a system window has focus, then it doesn't make sense
            // right now to interact with applications.
            WindowManager.LayoutParams attrs = win != null ? win.getAttrs() : null;
            if (attrs != null) {
                final int type = attrs.type;
                if (type == WindowManager.LayoutParams.TYPE_KEYGUARD
                        || type == WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG) {
                    // the "app" is keyguard, so give it the key
                    return 0;
                }
                final int typeCount = WINDOW_TYPES_WHERE_HOME_DOESNT_WORK.length;
                for (int i=0; i<typeCount; i++) {
                    if (type == WINDOW_TYPES_WHERE_HOME_DOESNT_WORK[i]) {
                        // don't do anything, but also don't pass it to the app
                        return -1;
                    }
                }

                final int flag = attrs.flags;

                if ((flag & WindowManager.LayoutParams.FLAG_HOMEKEY_DISPATCHED) != 0) {
                    // the window wants to handle the home key, so dispatch it to it.
                    return 0;
                }
            }

            return -1;
     }

在此函数中，如果返回 0，则 home 键会交给 app 来处理，如果返回 -1 ，则不会处理 home 键。

在app 的你要屏蔽home 键的activity 中，只需要添加该标志就可以了

getWindow().addFlags(WindowManager.LayoutParams.FLAG_HOMEKEY_DISPATCHED);

如果要使home 键有效，再 clearFlags 即可。

getWindow().clearFlags(WindowManager.LayoutParams.FLAG_HOMEKEY_DISPATCHED);

从上面的代码来看，应该设置 window 的类型也是有效的，但不知为何在 4.0 中不取作用，打Log 看也不取效。不知何故。

this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);

作者：fulinwsuafcie