我正在尝试创建一个应用程序，该应用程序提供已安装应用程序的列表，并在单击项目时启动另一个活动，该活动指出已安装应用程序所需的权限。 我获得了已安装的应用程序列表，但是当我单击任何应用程序而不是启动新活动时，应用程序强制关闭。 我正在关注tutorial
MainActivity
package com.example.appslist;
import java.util.List;
import com.example.appslist.adapter.ApkAdapter;
import com.example.appslist.app.AppData;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
public class ApkListActivity extends Activity implements OnItemClickListener {
PackageManager packageManager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
packageManager = getPackageManager();
List<PackageInfo> packageList = packageManager
.getInstalledPackages(PackageManager.GET_PERMISSIONS);
ListView mylistview= (ListView) findViewById(android.R.id.list);
mylistview.setAdapter(new ApkAdapter(this, packageList, packageManager));
mylistview.setOnItemClickListener(this);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long row) {
PackageInfo packageInfo = (PackageInfo) parent
.getItemAtPosition(position);
AppData appData = (AppData) getApplicationContext();
appData.setPackageInfo(packageInfo);
Intent appInfo = new Intent(getApplicationContext(), ApkInfo.class);
startActivity(appInfo);
}
}
logcat的
04-02 11:16:04.536: E/asset(2777): MAS: getAppPckgAndVerCode package: com.example.appslist === version 1
04-02 11:16:04.559: D/dalvikvm(2777): Trying to load lib lib_glossary.so 0x0
04-02 11:16:04.559: I/dalvikvm(2777): Unable to dlopen(lib_glossary.so): Cannot load library: load_library[1083]: Library 'lib_glossary.so' not found
04-02 11:16:04.567: E/MBGlossaryManager(2777): lib_glossary.so can't be loaded
04-02 11:16:04.700: E/asset(2777): MAS: getAppPckgAndVerCode package: com.google.android.location === version 8
04-02 11:16:04.708: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.launcher === version 8
04-02 11:16:04.708: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.defcontainer === version 8
04-02 11:16:04.708: E/asset(2777): MAS: getAppPckgAndVerCode package: com.navngo.igo.javaclient === version 148360
04-02 11:16:04.715: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.contacts === version 8
04-02 11:16:04.723: E/asset(2777): MAS: getAppPckgAndVerCode package: com.arcsoft.photoworkshop === version 5
04-02 11:16:04.778: D/dalvikvm(2777): GC_EXTERNAL_ALLOC freed 822 objects / 60704 bytes in 56ms
04-02 11:16:04.786: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.phone === version 8
04-02 11:16:04.794: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.calculator2 === version 8
04-02 11:16:04.794: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.htmlviewer === version 8
04-02 11:16:04.801: E/asset(2777): MAS: getAppPckgAndVerCode package: com.example.myfirstapp === version 1
04-02 11:16:04.801: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.providers.calendar === version 8
04-02 11:16:04.809: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.bluetooth === version 8
04-02 11:16:04.809: E/asset(2777): MAS: getAppPckgAndVerCode package: com.example.sessionmanagement === version 1
04-02 11:16:04.817: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.calendar === version 8
04-02 11:16:04.817: E/asset(2777): MAS: getAppPckgAndVerCode package: com.google.android.location === version 8
04-02 11:16:04.817: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.launcher === version 8
04-02 11:16:04.825: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.defcontainer === version 8
04-02 11:16:04.825: E/asset(2777): MAS: getAppPckgAndVerCode package: com.navngo.igo.javaclient === version 148360
04-02 11:16:04.872: E/asset(2777): MAS: getAppPckgAndVerCode package: com.android.contacts === version 8
04-02 11:16:06.536: D/AndroidRuntime(2777): Shutting down VM
04-02 11:16:06.536: W/dalvikvm(2777): threadid=1: thread exiting with uncaught exception (group=0x400207e0)
04-02 11:16:06.551: E/AndroidRuntime(2777): FATAL EXCEPTION: main
04-02 11:16:06.551: E/AndroidRuntime(2777): java.lang.ClassCastException: android.app.Application
04-02 11:16:06.551: E/AndroidRuntime(2777): at com.example.appslist.ApkListActivity.onItemClick(ApkListActivity.java:44)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.widget.AdapterView.performItemClick(AdapterView.java:284)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.widget.ListView.performItemClick(ListView.java:3444)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1696)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.os.Handler.handleCallback(Handler.java:587)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.os.Handler.dispatchMessage(Handler.java:92)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.os.Looper.loop(Looper.java:143)
04-02 11:16:06.551: E/AndroidRuntime(2777): at android.app.ActivityThread.main(ActivityThread.java:4717)
04-02 11:16:06.551: E/AndroidRuntime(2777): at java.lang.reflect.Method.invokeNative(Native Method)
04-02 11:16:06.551: E/AndroidRuntime(2777): at java.lang.reflect.Method.invoke(Method.java:521)
04-02 11:16:06.551: E/AndroidRuntime(2777): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
04-02 11:16:06.551: E/AndroidRuntime(2777): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
04-02 11:16:06.551: E/AndroidRuntime(2777): at dalvik.system.NativeStart.main(Native Method)
04-02 11:16:08.137: I/Process(2777): Sending signal. PID: 2777 SIG: 9
请帮忙。非常抱歉，如果问题含糊不清。很长一段时间以后，我无法弄明白，我正在努力。
提前致谢：）
答案 0 :(得分：2)
这是因为您正在使用列表活动。当您使用Activity时，您的listview必须具有id
在xml中设置listview id
android:id="@android:id/list
并且像这样得到它
ListView yorulistview= (ListView) findViewById(android.R.id.list);