Question

在我的应用程序中，我有一个用户安装的应用程序列表，并希望为该列表创建搜索功能。现在，这是我的编码：

       // create new adapter
AppInfoAdapter adapter = new AppInfoAdapter(this, Utilities.getInstalledApplication(this),   getPackageManager());
// load list application
mListAppInfo = (ListView)findViewById(R.id.lvApps);
// set adapter to list view
mListAppInfo.setAdapter(adapter);
// search bar
inputSearch = (EditText) findViewById(R.id.inputSearch);

inputSearch.addTextChangedListener(new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {

        // When user changed the Text
        // Drag_and_Drop_App.this.adapter.getFilter().filter(cs);  
        Drag_and_Drop_App.this.adapter.getFilter().filter(cs);

    }

    @Override
    public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
            int arg3) {
        // TODO Auto-generated method stub

    }

    @Override
    public void afterTextChanged(Editable arg0) {
        // TODO Auto-generated method stub                          
    }
    });

当我在此行收到错误时会出现此问题：

Drag_and_Drop_App.this.adapter.getFilter().filter(cs);

它说我的基本适配器中没有定义“getFilter（）”，这就是：

package com.example.awesomefilebuilderwidget;

IMPORTS

public class AppInfoAdapter extends BaseAdapter {
private Context mContext;
private List mListAppInfo;
private PackageManager mPackManager;

public AppInfoAdapter(Context c, List list, PackageManager pm) {
mContext = c;
mListAppInfo = list;
mPackManager = pm;
}

@Override
public int getCount() {
return mListAppInfo.size();
}

@Override
public Object getItem(int position) {
return mListAppInfo.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// get the selected entry
ApplicationInfo entry = (ApplicationInfo) mListAppInfo.get(position);

// reference to convertView
View v = convertView;

// inflate new layout if null
if(v == null) {
    LayoutInflater inflater = LayoutInflater.from(mContext);
    v = inflater.inflate(R.layout.layout_appinfo, null);
}

// load controls from layout resources
ImageView ivAppIcon = (ImageView)v.findViewById(R.id.ivIcon);
TextView tvAppName = (TextView)v.findViewById(R.id.tvName);
TextView tvPkgName = (TextView)v.findViewById(R.id.tvPack);

// set data to display
ivAppIcon.setImageDrawable(entry.loadIcon(mPackManager));
tvAppName.setText(entry.loadLabel(mPackManager));
tvPkgName.setText(entry.packageName);

// return view
return v;
}

@Override
public Filter getFilter() {
// TODO Auto-generated method stub
return filter;
}
}

我在stackoverflow上查看了最后一部分“public Filter ...”。但是现在，我需要一个自定义过滤器来进行搜索。我可以用什么？（我已经尝试了一件事，但它不起作用）

Answer 1

未定义方法getFilter()，因为您的适配器必须实现Filterable接口，因此只需在适配器上添加“implements Filterable”：

public class AppInfoAdapter extends BaseAdapter implements Filterable {
    // your stuff
}

和你的getFilter

@Override
public Filter getFilter() {
    if(filter == null) {
        filter = new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                FilterResults results = new FilterResults();
                List<ApplicationInfo> myFilteredAppList = new ArrayList<ApplicationInfo>();
                constraint = constraint.toString().toLowerCase();

                for (ApplicationInfo appInfo : originalListAppInfo) {
                    String somefield = appInfo.getSomeField();
                    if (somefield.toLowerCase().contains(constraint.toString())) {
                        myFilteredAppList.add(appInfo);
                    }
                }
                results.count = myFilteredAppList.size();
                results.values = myFilteredAppList;
                return results;
            }

            @Override
            protected void publishResults(CharSequence constraint, FilterResults results) {
                mListAppInfo = (List<ApplicationInfo>)results.values;
                notifyDataSetChanged();
            }
        };
    }
    return filter;
}

请注意，我已经通过在创建适配器期间创建的原始列表（originalListAppInfo）的副本进行了迭代。

private List<ApplicationInfo> originalListAppInfo;
private List<ApplicationInfo> mListAppInfo;

private Filter filter;

public AppInfoAdapter(Context context, List<ApplicationInfo> listApp) {
    this.context = context;
    this.originalListAppInfo = this.mListAppInfo = listApp;
}

希望这有帮助。：）

如何为搜索功能制作自定义过滤器

1 个答案: