单击 ImageView 时如何打开滑动导航抽屉？

Question

我正在尝试在我的仪表板Activity 上实现Navigation Drawer Activity。在我的应用程序中，我创建了一个主题，其中删除了“工具栏/操作栏”，并将我的汉堡菜单的 ImageView 放在 custom layout 上，并将其包含在我的仪表板布局中。我想要的是，当单击此ImageView 时，将显示滑动抽屉。

我尝试通过 com.project.projectname -> 新建 -> 活动 -> 'Navigation Drawer Activity' 添加 Navigation Drawer Activity 并自动添加 NavigationActivity class , activity_navigation.xml app_bar_navigation.xml, etc。

但我想知道如何打开抽屉？ 在我的Dashboard Activity 我添加了这个

 public class DashboardActivity extends AppCompatActivity {

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.dashboard);

   View side_tab = findViewById(R.id.side_tab);
    expanded_menu = (ImageView) side_tab.findViewById(R.id.expanded_menu);

  expanded_menu.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v) {
            // open drawer here 
        }
    });

另外，在NavigationActivity 中它使用ActionBarDrawerToggle，我不能使用它，因为我没有应用ActionBar。但是我可以使用什么替代方案？

这是我的NavigationActivity

public class NavigationActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_navigation);

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

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

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.navigation, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
    Intent goToSreen;

    if (id == R.id.nav_dashboard) {
        goToSreen = new Intent(NavigationActivity.this, DashboardActivity.class);
        startActivity(goToSreen);
    } else if (id == R.id.nav_others) {

    }

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

感谢您的热心帮助。

---

更新

所以在我的仪表板活动中，我添加了以下内容

NavigationActivity navigationActivity;

@Override
protected void onCreate(Bundle savedInstanceState) {

 super.onCreate(savedInstanceState);
    setContentView(R.layout.dashboard);

    View side_tab = findViewById(R.id.side_tab);
    expanded_menu = (ImageView) side_tab.findViewById(R.id.expanded_menu);

 expanded_menu.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v) {
            navigationActivity = new NavigationActivity() ;
            navigationActivity.drawer.openDrawer(GravityCompat.START);
        }
    });

在我的导航活动中，我添加了一个全局变量

public class NavigationActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

DrawerLayout drawer;


 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_navigation);

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);

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

我已经设法在我的仪表板活动中调用了drawer，但是当我单击我的汉堡菜单时，滑动菜单仍然不显示。应用崩溃并显示java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.widget.DrawerLayout.openDrawer(int)' on a null object reference

Answer 1

将此添加到您的 NavigationActivity

public class NavigationActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

//Add this line
    public static DrawerLayout drawer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_navigation);

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();
.......

接下来改变这个

expanded_menu.setOnClickListener(new View.OnClickListener(){
            public void onClick(View v) {
                // open drawer here 
                NavigationActivity. drawer.openDrawer(GravityCompat.START);
        }
   });

试试这个希望它能解决你的问题。

Answer 2

在NavigationActivity中添加以下代码：

DrawerLayout mDrawerLayout;    // Declare globally

在onCreate()：

mDrawerLayout = (DrawerLayout) findViewById(R.id.nav_drawer);
 expanded_menu = (ImageView) side_tab.findViewById(R.id.expanded_menu);
expanded_menu.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v) {
            // open drawer here 
            mDrawerLayout.openDrawer(Gravity.LEFT);
        }
    });

如果抽屉是打开的，关闭它onBackPressed():

@Override
public void onBackPressed() {
    if (mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
        mDrawerLayout.closeDrawer(Gravity.LEFT);
        return;
    }
}

希望这会有所帮助。

Answer 3

我将我的NavigationActivity 扩展为我的DashboardActivity，如下所示

public class DashboardActivity extends NavigationActivity {

    side_tab = findViewById(R.id.side_tab);
    expanded_menu = (ImageView) side_tab.findViewById(R.id.expanded_menu);


  expanded_menu.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v) {
            side_tab.setVisibility(View.INVISIBLE);
            drawer.openDrawer(GravityCompat.START);
        }
    });

然后按照@Hassan Usman 和@tahsinRupam 的回答进行操作

之后我在我的dashboard.xml 中添加了DrawerLayout