ListView 分段加载数据

[java] view plaincopyprint?

ListView listView = getListView();
//添加到脚页显示  这个要继承ListActivity 实现OnScrollListener
listView.addFooterView(loadingLayout);

这位兄弟的Demo非常不错.

public class ListViewUpdate extends Activity implements OnScrollListener,
        OnItemClickListener {

    private List<ApplicationItemInfo> applicationItemInfoList;

    private List<ApplicationItemInfo> applicationItemInfoListTemp;

    private ApplicationItemAdapter applicationItemAdapter;

    private ListView listView;

    private LinearLayout loading;

    private Handler handler;

    private boolean refreshable;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        init();
        updateApplicationItemInfoList();
    }

    private void init() {
        setContentView(R.layout.main);
        listView = (ListView) findViewById(R.id.list);
        loading = (LinearLayout) findViewById(R.id.loading);

        applicationItemInfoList = new ArrayList<ApplicationItemInfo>();
        applicationItemAdapter = new ApplicationItemAdapter(this,
                applicationItemInfoList);
        handler = createHandler();
        refreshable = true;

        listView.setAdapter(applicationItemAdapter);
        listView.setOnItemClickListener(this);
        listView.setOnScrollListener(this);
    }

    private Handler createHandler() {
        Handler handler = new Handler() {

            @Override
            public void handleMessage(Message msg) {
                // TODO Auto-generated method stub
                super.handleMessage(msg);
                switch (msg.what) {
                case 1:
                    if (applicationItemInfoListTemp != null) {
                        ListViewUpdate.this.applicationItemInfoList
                                .addAll(applicationItemInfoListTemp);
                        ListViewUpdate.this.applicationItemAdapter
                                .notifyDataSetChanged();
                        ListViewUpdate.this.loading
                                .setVisibility(View.GONE);
                        ListViewUpdate.this.refreshable = true;
                    } else {
                        ListViewUpdate.this.loading
                                .setVisibility(View.GONE);
                        Toast.makeText(ListViewUpdate.this,
                                "All of applications have been shown!",
                                Toast.LENGTH_LONG).show();
                    }
                    break;
                default:
                    break;
                }
            }
        };
        return handler;
    }

    public Handler getHandler() {
        return handler;
    }

    private void updateApplicationItemInfoList() {
        new Thread(new Runnable() {

            @Override
            public void run() {
                // TODO Auto-generated method stub

                if (ListViewUpdate.this.applicationItemInfoList.size() < 80) {
                    ListViewUpdate.this.applicationItemInfoListTemp = ListViewUpdate.this
                            .getLocalApplicationInfo();
                } else {
                    ListViewUpdate.this.applicationItemInfoListTemp = null;
                }

                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                Message message = new Message();
                message.what = 1;
                ListViewUpdate.this.getHandler().sendMessage(message);
            }

        }).start();
    }

    private ArrayList<ApplicationItemInfo> getLocalApplicationInfo() {

        PackageManager packageManager = this.getPackageManager();
        ArrayList<ApplicationItemInfo> applicationItemInfoList = new ArrayList<ApplicationItemInfo>();
        List<PackageInfo> packageInfoList = packageManager
                .getInstalledPackages(0);

        for (int i = packageInfoList.size(); i > 0; i--) {

            ApplicationInfo applicationInfo = packageInfoList.get(i - 1).applicationInfo;

            if ((applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) <= 0) {
                try {
                    ApplicationItemInfo applicationItemInfo = new ApplicationItemInfo();

                    String packageName = packageInfoList.get(i - 1).packageName;
                    String[] permissions = packageManager.getPackageInfo(
                            packageName, PackageManager.GET_PERMISSIONS).requestedPermissions;

                    applicationItemInfo.setPackageName(packageName);
                    applicationItemInfo.setPermissions(permissions);

                    applicationItemInfo.setIcon(packageManager
                            .getApplicationIcon(applicationInfo));
                    applicationItemInfo.setName(packageManager
                            .getApplicationLabel(applicationInfo).toString());

                    applicationItemInfoList.add(applicationItemInfo);

                } catch (NameNotFoundException e) {
                    // TODO Auto-generated catch block
                }
            }
        }
        if ((!applicationItemInfoList.isEmpty())
                && (applicationItemInfoList.size() < 10)) {
            for (int i = applicationItemInfoList.size(); i < 10; i++) {
                applicationItemInfoList.add(applicationItemInfoList.get(9 - i));
            }
        }
        return applicationItemInfoList;
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
            int visibleItemCount, int totalItemCount) {
        // TODO Auto-generated method stub
        if ((firstVisibleItem + visibleItemCount == totalItemCount)
                && (totalItemCount != 0)) {
            if (refreshable) {
                refreshable = false;
                loading.setVisibility(View.VISIBLE);
                updateApplicationItemInfoList();
            }
        }
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onItemClick(AdapterView<?> arg0, View view, int position,
            long id) {
        // TODO Auto-generated method stub
        AlertDialog.Builder permissionDialog = new AlertDialog.Builder(this);
        permissionDialog.setIcon(applicationItemInfoList.get(position)
                .getIcon());
        permissionDialog.setTitle(applicationItemInfoList.get(position)
                .getName());
        String[] permissions = applicationItemInfoList.get(position)
                .getPermissions();

        StringBuffer temp = new StringBuffer();
        if (permissions != null) {
            for (int i = 0; i < permissions.length; i++) {
                temp.append(permissions[i]);
                temp.append("\n");
            }
        } else {
            temp.append("permission is null");
        }
        permissionDialog.setMessage(temp.toString());
        permissionDialog.setPositiveButton("OK",
                new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        dialog.cancel();
                    }
                });
        permissionDialog.create().show();
    }
}