Java 如何避免单击抽屉中的同一项目?
我通过创建BaseActivity为所有活动准备了一个抽屉:Java 如何避免单击抽屉中的同一项目?,java,android,android-design-library,androiddesignsupport,Java,Android,Android Design Library,Androiddesignsupport,我通过创建BaseActivity为所有活动准备了一个抽屉: public class BaseActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener { private static final String SELECTED_ITEM_ID = "selected_id"; public DrawerLayout mDrawerLay
public class BaseActivity extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListener {
private static final String SELECTED_ITEM_ID = "selected_id";
public DrawerLayout mDrawerLayout;
public Toolbar mToolBar;
public NavigationView mDrawer;
public ActionBarDrawerToggle mdrawerToggle;
private int mSelectedId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState != null){
mSelectedId = savedInstanceState.getInt(SELECTED_ITEM_ID);
}
Log.d("aoi", "save instance "+String.valueOf(mSelectedId));
}
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
Intent intent = null;
if(mSelectedId != menuItem.getItemId()){
mSelectedId = menuItem.getItemId();
Log.d("aoi", "selected item "+String.valueOf(mSelectedId));
mDrawerLayout.closeDrawer(GravityCompat.START);
switch (menuItem.getItemId()){
case R.id.agency_menu_item:
intent = new Intent(this, AgencyActivity.class);
startActivity(intent);
break;
}
}
return false;
}
public void initDrawer(){
mToolBar = (Toolbar) findViewById(R.id.app_bar);
setSupportActionBar(mToolBar);
mDrawer = (NavigationView) findViewById(R.id.main_drawer);
mDrawer.setNavigationItemSelectedListener(this);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_parent);
mdrawerToggle = new ActionBarDrawerToggle(
this,
mDrawerLayout,
mToolBar,
R.string.drawer_open,
R.string.drawer_close);
mDrawerLayout.setDrawerListener(mdrawerToggle);
// indicator based on whether the drawerlayout is in open or closed
mdrawerToggle.syncState();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(SELECTED_ITEM_ID, mSelectedId);
}
}
并将通过我的活动得到扩展
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class AgencyActivity extends BaseActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_agency);
initDrawer();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_agency, 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);
}
}
但我的问题是,如果抽屉中的项目已经显示活动,如何禁用它?
例如:我单击抽屉上的“代理”项目,当我已经参与该活动时,我将无法再次单击它,以避免打开新的AgencyActivity
我尝试使用onSaveInstanceState
保存所选项目的值,并在再次尝试选择时进行比较,但没有成功。我认为当通过intent调用新活动时,它会回到零
我目前正在使用Android设计支持库 单击时只需禁用菜单:
menu.getItem(menuItem.getItemId()).setEnabled(false);
然后在必要时使用
setEnabled(true)启用它
很抱歉问这个问题,我可以把它放在哪里?内部onNavigationItemSelected?因为当我尝试使用它时,menu.getItem(menuItem.getItemId()).setEnabled(false)中的“menu”;它是红色的。很抱歉,noob questiongetItem(int itemID)
接收id,在这种情况下,您必须将其放入菜单项id中,当您访问menuItem
并获取.getItemId()
时,您可以在任何部分使用getItem()onNavigationItemSelected
我是否要为getItem(int itemID)创建一个新方法?不!这个方法在菜单中,你只需在这里说哪个菜单位置禁用。。。检查api我让它工作了,但我不满意打开一个新活动的过渡。我将使用片段打开。谢谢你的帮助。