我在Android Studio创建了一个导航抽屉项目,现在我正在尝试与其他活动共享菜单(MainActivity)。
我的主要活动:
package br.com.pmarx.ihamster;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.support.design.widget.NavigationView.OnNavigationItemSelectedListener;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
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(menuItemListener);
}
@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.main, 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")
private OnNavigationItemSelectedListener menuItemListener = new OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.my_larder_general_activity) {
Intent myLarderViewActivity = new Intent(getApplicationContext(), MyLarderGeneralActivity.class);
startActivity(myLarderViewActivity);
} else if (id == R.id.my_plan_activity) {
Intent myPlanActivity = new Intent(getApplicationContext(), MyPlanActivity.class);
startActivity(myPlanActivity);
} else if (id == R.id.ins_item_larder) {
Intent insItemLarderActivity = new Intent(getApplicationContext(), InsItemLarderActivity.class);
startActivity(insItemLarderActivity);
} else if (id == R.id.ins_item_plan) {
Intent insItemPlanActivity = new Intent(getApplicationContext(), InsItemPlanActivity.class);
startActivity(insItemPlanActivity);
} else if (id == R.id.my_larder_kept_activity) {
Intent myLarderKeptActivity = new Intent(getApplicationContext(), MyLarderKeptActivity.class);
startActivity(myLarderKeptActivity);
} else if (id == R.id.my_larder_use_activity) {
Intent myLarderUseActivity = new Intent(getApplicationContext(), MyLarderUseActivity.class);
startActivity(myLarderUseActivity);
} else if (id == R.id.my_shopping_list_activity) {
Intent myShoppingListActivity = new Intent(getApplicationContext(), MyShoppingListActivity.class);
startActivity(myShoppingListActivity);
//Populando a Database Daqui
} else if (id == R.id.database_populate) {
DatabaseDAO crud = new DatabaseDAO(getBaseContext());
crud.popularDatabase();
//Populando a Database Até Aqui
} 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;
}
};
}
我的新活动以扩展MainActivity(和菜单):
package br.com.pmarx.ihamster;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class MyShoppingListActivity extends MainActivity {
private ListView listItem;
private CreateDatabase database;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_plan);
listItem = (ListView)findViewById(R.id.listView);
listItem.setOnItemClickListener(listItemListener);
};
@Override
protected void onResume() {
super.onResume();
DatabaseDAO crud = new DatabaseDAO(getBaseContext());
Cursor cursor = crud.loadShoppingList();
String[] fieldNames = new String[] {database.PROD_NOME, "volume3"};
int[] idViews = new int[] {R.id.tvProd, R.id.tvVolum};
SimpleCursorAdapter adapter = new SimpleCursorAdapter(getBaseContext(), R.layout.sel_item_plan, cursor, fieldNames, idViews, 0);
listItem = (ListView)findViewById(R.id.listView);
listItem.setAdapter(adapter);
};
private OnItemClickListener listItemListener = new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
//Passando parametro para a outra tela
Intent insertItemActivity = new Intent(getBaseContext(), InsItemLarderActivity.class);
insertItemActivity.putExtra("PROD_ID", String.valueOf(id));
startActivity(insertItemActivity);
}
};
}
首先,我收到错误“此活动已经有窗口装饰提供的操作栏”。所以,我改变了这样的风格:
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
我的activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<include layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_main_drawer" />
</android.support.v4.widget.DrawerLayout>
我的app_bar_main.xml
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
我的my_plan
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#fdb46d"
android:weightSum="1">
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:rowCount="1"
android:columnCount="4"
android:layout_gravity="center_horizontal">
</GridLayout>
<include
android:id="@+id/toolbar"
layout="@layout/activity_main" />
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:choiceMode="singleChoice"
android:clickable="false"
android:contextClickable="false" />
</LinearLayout>
但是,我开始得到错误“java.lang.NullPointerException:尝试在空对象引用上调用虚方法'boolean android.support.v4.widget.DrawerLayout.isDrawerOpen(int)'。
经过一些更改后,现在我收到错误“java.lang.NullPointerException:尝试在空对象引用上调用虚方法'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()'”
让我们一步一步来做。我真的很困惑。
先谢谢!
答案 0 :(得分:0)
启动create or replace PROCEDURE procPrintOutput
IS
-- var declarations ....
BEGIN
DECLARE
-- Get the list of Materialized views.
CURSOR LIST_OF_MatViews
IS select *
from user_mviews
where MVIEW_NAME = 'TEAM_AUD_MV_NR';
CURSOR CREATE_MatViews
IS SELECT *
FROM temp;
BEGIN
FOR Mat_View IN LIST_OF_MatViews
LOOP
BEGIN
DBMS_OUTPUT.PUT_LINE('owner : ' || Mat_View.OWNER || ' - name : ' || Mat_View.MVIEW_NAME);
-- save the create script of views to temp table.
l_stmt := 'insert into temp SELECT SYS.DBMS_METADATA.get_ddl (''MATERIALIZED_VIEW'', '''
|| Mat_View.MVIEW_NAME || ''') from dual';
EXECUTE IMMEDIATE (l_stmt);
DBMS_OUTPUT.PUT_LINE('inserted ... ');
-- drop the view.
--EXECUTE IMMEDIATE (drop_mat_view_logs_stmt || Mat_View.MVIEW_NAME);
--DBMS_OUTPUT.PUT_LINE('view log dropped ... ');
END;
END LOOP;
-- recreate view using the create script generated in the previous step.
FOR MV_CREATE_SCRIPT IN CREATE_MatViews
LOOP
BEGIN
DBMS_OUTPUT.PUT_LINE('SCRIPT : ' || MV_CREATE_SCRIPT.matViewLogQuery);
replace_stmt := 'select replace(''' || MV_CREATE_SCRIPT.matViewLogQuery || ''','';'','' '') from dual';
DBMS_OUTPUT.PUT_LINE('replace_stmt : ' || replace_stmt);
EXECUTE IMMEDIATE (replace_stmt) INTO updated_stmt;
DBMS_OUTPUT.PUT_LINE('Updated SCRIPT ?? ' || updated_stmt);
--EXECUTE IMMEDIATE(updated_stmt);
--DBMS_OUTPUT.PUT_LINE('view recreated ... ');
END;
END LOOP;
END;
END;
时
首先,调用onCreate方法并执行此行。
MyShoppingListActivity
调用父类的onCreate方法,它是MainActivity的onCreate方法。
所以super.onCreate(savedInstanceState);
在超级电话中执行。
然后执行setContentView(R.layout.activity_main);
,将布局设置为setContentView(R.layout.my_plan)
因此,如果您的R.layout.my_plan
xml文件中没有定义标识为R.id.toolbar
的工具栏,则查找工具栏行将返回null。
R.layout.my_plan
解决方案是在没有布局的情况下创建BaseActivity,而无需调用setContentView(...)方法。将所有设置视图代码放入Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
块。
然后使用相同的Id在子类Activities的layout.xml文件中定义Widgets。