应用程序和上下文的Android ClassCast异常

Question

我在listview的onitemclick方法中遇到ClassCast异常。在项目点击它应该转到下一个活动，但在项目点击应用程序强制关闭，它给出了类强制转换异常：

AppData appData =（AppData）getApplicationContext（）;

这是代码

使用活动：

 public class UsageActivity extends Activity
        implements OnItemClickListener {

      PackageManager packageManager;
        ListView apkList;



    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_usage);


        packageManager = getPackageManager();
        List<PackageInfo> packageList = packageManager
                .getInstalledPackages(PackageManager.GET_PERMISSIONS);




        apkList = (ListView) findViewById(R.id.applist);
         apkList.setAdapter(new ApkAdapter(this, packageList, packageManager));

            apkList.setOnItemClickListener(this);
        }


    @Override
public void onItemClick(AdapterView<?> parent, View view, int position, long row) {
    // TODO Auto-generated method stub

     PackageInfo packageInfo = (PackageInfo) parent
                .getItemAtPosition(position);
        AppData appData =  (AppData) getApplicationContext();
        appData.setPackageInfo(packageInfo);


        Intent appInfo = new Intent(getApplicationContext(), ApkInfo.class);
        startActivity(appInfo);

}

应用程序数据：

package com.example.ui_work;


    import android.app.Application;
    import android.content.pm.PackageInfo;

    public class AppData extends Application {

        PackageInfo packageInfo;

        public PackageInfo getPackageInfo() {
            return packageInfo;
        }

        public void setPackageInfo(PackageInfo packageInfo) {
            this.packageInfo = packageInfo;
        }

    }

请帮忙。