Question

我为活动设置了FLAG_SECURE（它包含敏感数据），但在一个特定的Fragment我需要清除它（因为od Android Beam）。

Window window = getActivity().getWindow();
window.clearFlags(WindowManager.LayoutParams.FLAG_SECURE);

此代码清除了标志（我在Fragment的onResume回调中有它），但问题是，它在下一次配置更改（屏幕旋转，...）之前不会生效同样的问题是在离开片段时再次设置标志。

有谁知道，我该怎么做才能解决这个问题？（我想过Activity.recreate()，这可行，但我不喜欢这个解决方案）如果可能，我不想为此特定屏幕创建单独的Activity。

Answer 1

编辑 ：添加了示例代码。

我来晚了，但无论如何我都会发布。这不是最好的解决方案（在我的诚实意见中），因为它可以在Android 4.x（5+很好）上显示“重新绘制”效果，但它至少起作用。我这样使用它：

/**
 * @param flagSecure adds/removes FLAG_SECURE from Activity this Fragment is attached to/from.
 */
public void applyFlagSecure(boolean flagSecure)
{
    Window window = getActivity().getWindow();
    WindowManager wm = getActivity().getWindowManager();

    // is change needed?
    int flags = window.getAttributes().flags;
    if (flagSecure && (flags & WindowManager.LayoutParams.FLAG_SECURE) != 0) {
        // already set, change is not needed.
        return;
    } else if (!flagSecure && (flags & WindowManager.LayoutParams.FLAG_SECURE) == 0) {
        // already cleared, change is not needed.
        return;
    }

    // apply (or clear) the FLAG_SECURE flag to/from Activity this Fragment is attached to.
    boolean flagsChanged = false;
    if (flagSecure) {
        window.addFlags(WindowManager.LayoutParams.FLAG_SECURE);
        flagsChanged = true;
    } else {
        // FIXME Do NOT unset FLAG_SECURE flag from Activity's Window if Activity explicitly set it itself.
        if (!(getActivity() instanceof YourFlagSecureActivity)) {
            // Okay, it is safe to clear FLAG_SECURE flag from Window flags.
            // Activity is (probably) not showing any secure content.
            window.clearFlags(WindowManager.LayoutParams.FLAG_SECURE);
            flagsChanged = true;
        }
    }

    // Re-apply (re-draw) Window's DecorView so the change to the Window flags will be in place immediately.
    if (flagsChanged && ViewCompat.isAttachedToWindow(window.getDecorView())) {
        // FIXME Removing the View and attaching it back makes visible re-draw on Android 4.x, 5+ is good.
        wm.removeViewImmediate(window.getDecorView());
        wm.addView(window.getDecorView(), window.getAttributes());
    }
}

来源 ：此解决方案基于 kdas 的示例：How to disable screen capture in Android fragment?

如何从Fragment中清除Android中的WindowManager标志

1 个答案: