Hey there, let's work through these two frustrating issues step by step!

1. Resolving the Persistent Gray Title Bar (Fullscreen/No Title Bar Not Working) #

It sounds like you're using the wrong theme type if you're working with modern Android components (like AppCompatActivity). The Theme.NoTitleBar.Fullscreen is an old, non-AppCompat theme that might not play nice with support library components. Here's what to try:

• Use the AppCompat-compatible fullscreen theme
  Update your AndroidManifest.xml to use an AppCompat theme instead. Replace your current theme with:

  android:theme="@style/Theme.AppCompat.Light.NoActionBar.FullScreen"
  

  If you need a custom theme, create one in styles.xml that inherits from this:

  <style name="AppFullScreenTheme" parent="Theme.AppCompat.Light.NoActionBar.FullScreen">
      <!-- Add your customizations here (if any) -->
  </style>
  

  Then reference AppFullScreenTheme in your manifest.

• Force fullscreen via code (fallback)
  If the theme change still doesn't work, add these lines in your Activity's onCreate() method, before calling setContentView():

  // Hide status bar and make activity fullscreen
  getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
                       WindowManager.LayoutParams.FLAG_FULLSCREEN);
  
  // If using AppCompatActivity, hide the support action bar too
  if (getSupportActionBar() != null) {
      getSupportActionBar().hide();
  }
  

• Check for accidental Toolbar in layout
  Double-check your activity layout file—if you've added a <Toolbar> widget manually, it might be showing up as that gray bar. Remove it or set its visibility to gone:

  <androidx.appcompat.widget.Toolbar
      ...
      android:visibility="gone"/>
  

2. Changing the Navigation Menu Icon Color #

The default navigation drawer icon's color is controlled by your theme's color attributes or can be modified directly. Try these methods:

• Customize via Toolbar style
  Define a custom Toolbar style in styles.xml that sets the icon color:

  <style name="CustomToolbarStyle" parent="Widget.AppCompat.Toolbar">
      <!-- Replace with your desired icon (optional) -->
      <item name="navigationIcon">@drawable/ic_menu_black_24dp</item>
      <!-- Set the icon color here -->
      <item name="colorControlNormal">@color/your_target_color</item>
  </style>
  

  Then apply this style to your Toolbar in the layout:

  <androidx.appcompat.widget.Toolbar
      ...
      style="@style/CustomToolbarStyle"/>
  

• Set color dynamically in code
  If you need to change the color at runtime, use this snippet after initializing your Toolbar:

  Toolbar toolbar = findViewById(R.id.toolbar);
  setSupportActionBar(toolbar);
  
  // Modify the navigation icon color
  Drawable navIcon = toolbar.getNavigationIcon();
  if (navIcon != null) {
      navIcon.setColorFilter(ContextCompat.getColor(this, R.color.your_color), 
                             PorterDuff.Mode.SRC_ATOP);
  }
  

• Adjust ActionBarDrawerToggle color
  If you're using ActionBarDrawerToggle with DrawerLayout, set its color directly:

  ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
          this, drawerLayout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
  drawerLayout.addDrawerListener(toggle);
  toggle.syncState();
  
  // Set the toggle icon color
  toggle.getDrawerArrowDrawable().setColor(ContextCompat.getColor(this, R.color.your_color));
  

Give these steps a shot—they should resolve both issues!

内容的提问来源于stack exchange，提问作者user1439582