Dialog 全屏显示

style：

<style name="Theme.Light.Dialog" parent="android:style/Theme.Dialog">
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:backgroundDimEnabled">false</item>
</style>

        AlertDialog dialog = new AlertDialog.Builder(this, R.style.Theme_Light_Dialog).create();
        dialog.show();

        Window window = dialog.getWindow();
        View mDialogView = getLayoutInflater().inflate(R.layout.layout_dialog, null);
        dialog.setContentView(mDialogView);
        WindowManager.LayoutParams lp = window.getAttributes();
        lp.width = ViewGroup.LayoutParams.MATCH_PARENT;
        lp.height = ViewGroup.LayoutParams.MATCH_PARENT;
        window.setAttributes(lp);
        WindowUtil.handleStatusBar(window);

public class WindowUtil {
    public static void handleStatusBar(Window window) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS
                    | WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
            window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
            window.setNavigationBarColor(Color.TRANSPARENT);
        }

    }
}