Android 无法访问nav_header_main.xml

有人能帮我解决这个问题吗？我尽了一切努力在代码中访问它们

public class MainActivity extends BaseActivity
implements NavigationView.OnNavigationItemSelectedListener {

private ImageView mDisplayImageView;
private TextView mNameTextView;
private TextView mEmailTextView;

NavigationView navigationView = (NavigationView) 
findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
 View navHeaderView = navigationView.getHeaderView(0);
 initNavHeader(navHeaderView);
}
private void initNavHeader(View view) {
mDisplayImageView = (ImageView) 
view.findViewById(R.id.imageView_display);
mNameTextView = (TextView) view.findViewById(R.id.textview_name);
mEmailTextView = (TextView) view.findViewById(R.id.textView_email);
}

---

试试这个，你可以像这样访问你的

nav_header\u main.xml的图像和文本视图

NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);       

mNameTextView = (TextView) navigationView.getHeaderView(0).findViewById(R.id.textview_name);
mEmailTextView = (TextView) navigationView.getHeaderView(0).findViewById(R.id.textView_email);
mDisplayImageView = (ImageView)navigationView.getHeaderView(0).findViewById(R.id.imageView_display);

您可以像这样使用onnavigationitem selected方法。。。
创建方法中所有定义导航视图的第一个

 NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
        navigationView.setCheckedItem(R.id.nav_frag1);

然后创建方法

public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        logo=(ImageView)findViewById(R.id.logo);
        logo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getBaseContext(),"Unable to get Permission",Toast.LENGTH_LONG).show();
            }
        });
        int id = item.getItemId();
        fragment = null;

        if (id == R.id.nav_frag1) {
            fragment = new HomeFragment();
        }
        /*else if (id == R.id.nav_gallery) {

        } else if (id == R.id.nav_slideshow) {

        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }*/

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

nav_header_main.xml在哪里？你面临什么问题？@JohnJoe我应该也上传这个吗？？？@NabEelKambOh你的问题很不清楚。您说无法访问nav_header_main.xml，但代码中没有无法访问nav_header_main.xml的内容。@JohnJoe我想从nav_header_main.xml访问我的图像视图，但它根本无法访问@Nilesh Checkgist@DevyaniKotadiya是的，谢谢Alotchel gist@NabEelKambOh你能解释一下有什么问题吗