Java 无法从Fragment强制转换为FragmentListView
虽然有几个人问了一些关于将片段投射到活动中的问题(以及这是如何不起作用的),但我找不到一个适合我的修复方法。我正在经历一个包含两个片段的主要活动。我可能遗漏了一些相当明显的东西:Java 无法从Fragment强制转换为FragmentListView,java,android,android-intent,android-fragments,Java,Android,Android Intent,Android Fragments,虽然有几个人问了一些关于将片段投射到活动中的问题(以及这是如何不起作用的),但我找不到一个适合我的修复方法。我正在经历一个包含两个片段的主要活动。我可能遗漏了一些相当明显的东西: <uses-sdk android:minSdkVersion="11" android:targetSdkVersion="19" /> <uses-permission android:name="android.permission.INTERNET"/> <app
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
出现错误:无法从片段强制转换到FragmentListView(第18行)
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
主要活动:
import android.app.Activity;
import android.app.FragmentManager;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
public class MainActivity extends Activity implements FragmentListView.OnSiteSelectedListener{
Fragmentwebview web;
FragmentListView list;
FragmentManager manager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
manager = getFragmentManager();
list = (FragmentListView) manager.findFragmentById(R.id.fragment1);
list.setRefrence(this);
}
@Override
public void onSiteSelected(int i) {
// TODO Auto-generated method stub
web = (Fragmentwebview) manager.findFragmentById(R.id.fragment2);
// Check for landscape mode
if (web!= null && web.isVisible())
{
web.setNewPage(i);
}
else
{
Intent intent = new Intent(this , FragmentSupport.class);
intent.putExtra("index", i);
startActivity(intent);
}
}
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
}
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
舱单:
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
导致错误的第一个片段
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
<LinearLayout android:layout_height="match_parent" android:layout_width="match_parent" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android">
<ListView
android:name="com.example.NumerAid.list"
android:id="@+id/list"
android:layout_height="match_parent"
android:layout_width="match_parent">
</ListView>
</LinearLayout>
编辑:添加FragmentListView类
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
package com.example.numeraid;
import android.R.string;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class FragmentListView extends Fragment implements AdapterView.OnItemClickListener
{
ListView list;
String [] websites = {"Google","Facebook","Twitter","Xda-developer"};
OnSiteSelectedListener SiteListener;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragmentlistview, container, false);
list = (ListView) v.findViewById(R.id.list);
list.setAdapter(new ArrayAdapter<string>(getActivity().getApplicationContext(), android.R.layout.simple_list_item_1));
list.setOnItemClickListener(this);
return v;
}
@Override
public void onItemClick(AdapterView adapterView, View view, int position, long l)
{
SiteListener.onSiteSelected(position);
}
// Container Activity must implement this interface
public interface OnSiteSelectedListener {
public void onSiteSelected(int i);
}
public void setRefrence(OnSiteSelectedListener siteListener)
{
this.SiteListener = siteListener;
}
}
package com.example.numeraid;
导入android.R.string;
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.AdapterView;
导入android.widget.ArrayAdapter;
导入android.widget.ListView;
公共类FragmentListView扩展了片段实现AdapterView.OnItemClickListener
{
列表视图列表;
String[]网站={“谷歌”、“Facebook”、“Twitter”、“Xda开发者”};
OnSiteSelectedListener站点Listener;
@凌驾
创建时的公共void(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
视图v=充气机。充气(R.layout.fragmentlistview,容器,假);
list=(ListView)v.findViewById(R.id.list);
setAdapter(新的ArrayAdapter(getActivity().getApplicationContext(),android.R.layout.simple_list_item_1));
list.setOnItemClickListener(此);
返回v;
}
@凌驾
公共虚线单击(AdapterView AdapterView,视图视图,内部位置,长l)
{
SiteListener.onSiteSelected(位置);
}
//容器活动必须实现此接口
SiteSelectedListener上的公共接口{
选定场地上的公共空间(int i);
}
public void setreference(在SiteSelectedListener站点Listener上)
{
this.SiteListener=SiteListener;
}
}
感谢@corsair的回答,最初发布为:
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
我猜您的
FragmentListView
类扩展了android.support.v4.app.Fragment
而不是android.app.Fragment
。如果要使用支持版本,则应
使用getSupportFragmentManager()
而不是getFragmentManager()
。否则,你需要
扩展android.app.Fragment
,就像你在下面的教程中所做的那样
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.numeraid.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.numeraid.FragmentSupport"
android:label="@string/title_activity_fragment_support" >
</activity>
<activity
android:name="com.example.numeraid.FragmentListView"
android:label="@string/title_activity_fragment_list_view" >
</activity>
<activity
android:name="com.example.numeraid.Fragmentwebview"
android:label="@string/title_activity_fragmentwebview" >
</activity>
</application>
</manifest>
简单回答:你的
FragmentListView
不是Fragment
@user3739849谢谢你的回复,我应该做些什么更改?我仍然卡住了。FragmentListView的(部分)代码如下:“package com.example.numeraid;公共类FragmentListView扩展了Fragment实现AdapterView.OnItemClickListener{ListView列表;String[]网站={“Google”、“Facebook”、“Twitter”、“Xda开发者”};OnSiteSelectedListener SiteListener;@Override public void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);}“我猜您的FragmentListView
类扩展了android.support.v4.app.Fragment
,而不是android.app.Fragment
。如果要使用支持版本,则应使用getSupportFragmentManager()
而不是getFragmentManager()
。否则,您需要像下面的教程中所做的那样,将android.app.Fragment扩展到所有地方。@corsair992很抱歉没有包括此内容,但这里是我的导入内容。我试图保持在字符限制之内。此外,我还读到了关于getSupport的文章,但它导致了另一个错误包com.example.numeraid;导入android.app.Fragment;导入android.os.Bundle;导入android.util.Log;导入android.view.LayoutInflater;导入android.view.view;导入android.view.ViewGroup;导入android.webkit.WebView;公共类Fragmentwebview扩展了片段{'