Question

我遇到一个始终发生的错误：引起：java.lang.NullPointerException。这是我的源代码

FrameLayout frameLayout1 = (FrameLayout) findViewById(R.id.frameContainer1);
        LayoutInflater layoutInflater1 = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view1 = layoutInflater1.inflate(R.layout.activity_add_hm, null, false);
        frameLayout1.addView(view1);


        drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawerListView = (ListView) findViewById(R.id.drawer_listview);

        ViewGroup header = (ViewGroup) layoutInflater1.inflate(R.layout.nav_header_main, drawerListView, false);
        drawerListView.addHeaderView(header, null, false);

        menuButton1 = (ImageButton) findViewById(R.id.menuButton1);
        menuButton1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                drawerLayout.openDrawer(GravityCompat.START);

            }
        });

有人可以帮帮我吗？提前谢谢。

Answer 1

您的案例中Null指针异常的可能原因可能来自

任何 findViewById（）方法。

原因是您的视图ID可能不会出现在活动或片段布局或您的虚增布局中。

可以这样打电话

drawerLayout = (DrawerLayout) view1.findViewById(R.id.drawer_layout);
drawerListView = (ListView) voew1.findViewById(R.id.drawer_listview); 

ViewGroup header = (ViewGroup) layoutInflater1.inflate(R.layout.nav_header_main, drawerListView, false);
 drawerListView.addHeaderView(header, null, false);
 menuButton1 = (ImageButton) header.findViewById(R.id.menuButton1);

显示java.lang.NullPointerException

1 个答案: