我正在使用可折叠的操作栏。 尝试启动新活动时遇到错误:无法解析构造函数'Intent(匿名android.support.design.widget.NavigationView.OnNavigationItemSelectedListener,java.lang.Class)'
请帮助我:
我们可以使用导航抽屉菜单项中的开始新活动点击吗?
或者
我们只能选择在菜单项单击
上替换和显示导航抽屉中的片段FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.containerView,new SentFragment()).commit();
如果是,那么如何替换tab活动和viewpager并设置操作栏高度?
activity_main.xml
<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/drawerLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.test.app.activities.MainActivity">
<android.support.design.widget.CoordinatorLayout
android:id="@+id/rootLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="@dimen/app_bar_height"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="48dp"
android:minHeight="?attr/actionBarSize"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
<android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorHeight="4dp"
app:tabGravity="fill"
app:tabMode="scrollable"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fabBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_marginBottom="@dimen/fab_margin_bottom"
android:layout_marginRight="@dimen/fab_margin_right"
android:src="@drawable/ic_plus"
app:borderWidth="0dp"
app:fabSize="normal" />
</android.support.design.widget.CoordinatorLayout>
<android.support.design.widget.NavigationView
android:id="@+id/navigation"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:headerLayout="@layout/nav_header"
app:itemIconTint="@color/nav_item_icon_tint_color"
app:itemTextColor="@color/nav_item_text_color"
app:menu="@menu/navigation_drawer_items" />
MainActivity.java
navigation = (NavigationView) findViewById(R.id.navigation);
navigation.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
int id = menuItem.getItemId();
drawerLayout.closeDrawers();
switch (id){
case R.id.home:
//do something here
//open new activity
/*unable to start activity*/
//Intent intent = new Intent(this, NewActivity.class);
/* error on above line shown: Cannot resolve constructor 'Intent(anonymous android.support.design.widget.NavigationView.OnNavigationItemSelectedListener, java.lang.Class<com.test.app.activities.RouteActivity>)'*/
break;
case R.id.logout:
//add navigation drawer item onclick method here
break;
}
return false;
}
});
答案 0 :(得分:10)
根据Android Docs开始新活动,您必须这样做:
1)在你的班级中添加这一行:
import android.content.Intent;
2)向清单添加新活动,如下所示:
<activity
android:name=".YourActivityName"
android:label="YourActivityName">
<intent-filter>
<action android:name="package.name.YOURACTIVITYNAME" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
3)使用startActivity()
方法启动活动,如下所示:
Intent newAct = new Intent(getApplicationContext(), YourActivityName.class);
startActivity(newAct);
3a)如果您的课程延长Activity
,您可以通过this
代替getApplicationContext()
:
Intent newAct = new Intent(this, YourActivityName.class);
startActivity(newAct);
3b)如果您的班级延伸Fragment
,您必须使用getActivity()
传递上下文:
Intent newAct = new Intent(getActivity(), YourActivityName.class);
startActivity(newAct);
答案 1 :(得分:2)
你写道:
/*unable to start activity*/
Intent intent = new Intent(this, NewActivity.class);
无法解析构造函数'Intent(匿名android.support.design.widget.NavigationView.OnNavigationItemSelectedListener,java.lang.Class)'
this
有一个NavigationView.OnNavigationItemSelectedListener
的实例。
但Intent
的第一个构造函数参数应为Context
。
因此将Context设置为NavigationView.OnNavigationItemSelectedListener
之外的最终变量:
final Context context = this;
navigation = (NavigationView) findViewById(R.id.navigation);
navigation.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
@Override
...
然后将上下文传递给Intent
的构造函数。
Intent intent = new Intent(context, NewActivity.class);
这将是有效的。
或者,我不会使用匿名对象。我会在MainActivity中实现NavigationView.OnNavigationItemSelectedListener
。
MainActivity extends Activity
implements NavigationView.OnNavigationItemSelectedListener {
...
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
...
Intent intent = new Intent(this, NewActivity.class);
通过这种方式,您可以将this
用作Context
的实例。