如何使底部导航栏可见?

How to make a bottom navigation bar visible?

导航栏如图所示1.But我在开发和构建应用程序时,没有导航栏。
请帮我解决这个问题

在您的 activity 中添加此代码:

private int currentApiVersion;

 final int flags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_FULLSCREEN
            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
// This work only for android 4.4+

currentApiVersion = android.os.Build.VERSION.SDK_INT;

if (currentApiVersion >= Build.VERSION_CODES.KITKAT) {

    getWindow().getDecorView().setSystemUiVisibility(flags);

    // Code below is to handle presses of Volume up or Volume down.
    // Without this, after pressing volume buttons, the navigation bar will
    // show up and won't hide
    final View decorView = getWindow().getDecorView();
    decorView
            .setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener() {

                @Override
                public void onSystemUiVisibilityChange(int visibility) {
                    if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
                        decorView.setSystemUiVisibility(flags);
                    }
                }
            });
}

如果只隐藏导航栏,只添加包含导航的flags

试试这个:

getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);

您还可以查看文档:check here