【发布时间】：2017-04-13 10:33:26
【问题描述】：
我有一个列表视图，上面有一个搜索 EditText。列表视图中的每一行都包含几个文本和图片。当用户在搜索 EditText 中输入关键字时，我希望使用包含该关键字的行来更新列表视图。我借用了this问题中的实现，如下所示。
我的自定义适配器：
public class CustomAdapter extends BaseAdapter implements Filterable {
private LayoutInflater inflater;
private ArrayList<CustomObject> objects;//mOriginalValues
private Activity activity;
private ArrayList<Bitmap> newsImageList;
private Context context;
private ArrayList<CustomObject> filteredObjects; // Values to be displayed after filtering
private class ViewHolder {
TextView titleTextView;
TextView dateTextView;
TextView bodyTextView;
ImageView logoView;
ImageView newsImageView;
ProgressBar progressBar;
}
public CustomAdapter(Context context, ArrayList<CustomObject> objects, Activity activity) {
// super(context, R.layout.news_item, objects);
inflater = LayoutInflater.from(context);
this.objects = objects;
this.filteredObjects=objects;
this.activity= activity;
this.newsImageList= new ArrayList<Bitmap>();
this.context= context;
for(int i=0; i<objects.size(); i++)
newsImageList.add(null);
}
@Override
public int getCount() {
return filteredObjects.size();
}
@Override
public CustomObject getItem(int position) {
return filteredObjects.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println("IN GET VIEW");
ViewHolder holder = null;
if(convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.news_item, null);
holder.titleTextView = (TextView) convertView.findViewById(R.id.txtTitle);
holder.dateTextView = (TextView) convertView.findViewById(R.id.txtDate);
holder.bodyTextView = (TextView) convertView.findViewById(R.id.txtBody);
holder.logoView= (ImageView) convertView.findViewById(R.id.source_imageView);
holder.newsImageView= (ImageView) convertView.findViewById(R.id.news_imageView);
holder.progressBar= (ProgressBar) convertView.findViewById(R.id.img_progress_bar);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.titleTextView.setText(objects.get(position).getTitle());
holder.dateTextView.setText(objects.get(position).getDate());
holder.bodyTextView.setText(objects.get(position).getBody());
//for the source logo
String uri = "@drawable/"+objects.get(position).getSource_logo()+"_logo";
int imageResource = activity.getResources().getIdentifier(uri, null, activity.getPackageName());
Drawable res =activity.getResources().getDrawable(imageResource);
holder.logoView.setImageDrawable(res);
//the news image
String newsImageURL = objects.get(position).getNewsImageURL();
if(newsImageURL!=null) {
// show The Image in a ImageView
//pre-execute
holder.progressBar.setVisibility(View.VISIBLE);
holder.newsImageView.setVisibility(View.VISIBLE);
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) holder.bodyTextView.getLayoutParams();
params.addRule(RelativeLayout.BELOW, R.id.relative_container);
Picasso.with(context).load(newsImageURL).into(holder.newsImageView);//EXECUTE in background
holder.progressBar.setVisibility(View.INVISIBLE);//post-execute
}
else
{
System.out.println("NO IMAGE");
//adjusting the view
holder.progressBar.setVisibility(View.INVISIBLE);
holder.newsImageView.setVisibility(View.GONE);
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) holder.bodyTextView.getLayoutParams();
params.addRule(RelativeLayout.BELOW, R.id.txtDate);
}
return convertView;
}
@Override
public Filter getFilter() {
Filter filter = new Filter() {
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint,FilterResults results) {
filteredObjects = (ArrayList<CustomObject>) results.values; // has the filtered values
notifyDataSetChanged(); // notifies the data with new filtered values
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
System.out.println("FILTERING with the keyword:"+ constraint);
FilterResults results = new FilterResults(); // Holds the results of a filtering operation in values
ArrayList<Object> FilteredArrList = new ArrayList<Object>();
if (objects == null) {
objects = new ArrayList<CustomObject>(filteredObjects); // saves the original data in mOriginalValues
}
/********
*
* If constraint(CharSequence that is received) is null returns the mOriginalValues(Original) values
* else does the Filtering and returns FilteredArrList(Filtered)
*
********/
if (constraint == null || constraint.length() == 0) {
// set the Original result to return
results.count = objects.size();
results.values = objects;
} else {
constraint = constraint.toString().toLowerCase();
for (int i = 0; i < objects.size(); i++) {
System.out.println("loop "+i);
String title = objects.get(i).getTitle();
String date = objects.get(i).getDate();
String body = objects.get(i).getBody();
String source_logo = objects.get(i).getSource_logo();
String newsImageURL = objects.get(i).getNewsImageURL();
System.out.println("title of this item:"+title+", key word:"+constraint.toString());
if (title.contains(constraint.toString()) || date.contains(constraint.toString()) || body.contains(constraint.toString())) {
System.out.println("FOUND!");
FilteredArrList.add(new CustomObject(title,date, body, source_logo, newsImageURL));
}
}
// set the Filtered result to return
results.count = FilteredArrList.size();
results.values = FilteredArrList;
}
return results;
}
};
return filter;
}
}
class CustomObject {
private String title;
private String date;
private String body;
private String source_logo;
private String newsImageURL;
public CustomObject(String prop1, String prop2, String prop3, String prop4, String prop5) {
this.title = prop1;
this.date = prop2;
this.body=prop3;
this.source_logo=prop4;
this.newsImageURL=prop5;
}
public String getTitle() {
return title;
}
public String getDate() {
return date;
}
public String getBody(){
return body;
}
public String getSource_logo()
{
return source_logo;
}
public String getNewsImageURL(){ return newsImageURL; }
}
在我的活动中：
listView = (ListView) activity.findViewById(R.id.activity_main_listview);//news list view (title, date, body per item)
searchEditText = (EditText) activity.findViewById(R.id.news_search_editText);
// Add Text Change Listener to EditText
searchEditText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// Call back the Adapter with current character to Filter
System.out.println("TEXT CHANGED!");
customAdapter.getFilter().filter(s.toString());
//listView.setAdapter(customAdapter);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void afterTextChanged(Editable s) {
//customAdapter.getFilter().filter(s.toString());
}
});
//preparing the news titles, dates, first part of bodies, and source logo.
ArrayList<CustomObject> objects = new ArrayList<CustomObject>();
for (int i = 0; i < titleList.size(); i++)
objects.add(new CustomObject(titleList.get(i), dateList.get(i), reduceTextLetters(textList.get(i), 150) + "...", sourceList.get(i), imageURLList.get(i)));
customAdapter = new CustomAdapter(activity, objects, activity);
listView.setAdapter(customAdapter);
我的活动 XML 文件：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<RelativeLayout
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true">
<EditText
android:id="@+id/news_search_editText"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="البحث"
/>
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/activity_main_swipe_refresh_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/news_search_editText">
<ListView
android:id="@+id/activity_main_listview"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
</ListView>
</android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout>
<Button
android:text="تحديث ↑"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/refresh_button"
android:background="@drawable/button_refresh"
android:layout_alignParentTop="true"
android:layout_centerInParent="true"
android:layout_gravity="center"
android:layout_marginTop="50dp"
/>
</RelativeLayout>
很遗憾，过滤的行为不正确。虽然我可以在日志中看到关键字与每行内容的比较是正确的，并且只有匹配的关键字被添加到过滤列表中，但更新的列表是不正确的。当我输入列表中的关键字时，它会为我显示列表中的前几项（其中一些与关键字无关）并删除其余项。当我输入不在列表中的关键字时，它会清除列表视图。因此，该行为是奇怪和出乎意料的。有人可以提出解决方案吗？
【问题讨论】：
标签： android listview custom-adapter android-filterable