通过自定义listView同时选择和搜索不起作用
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【中文标题】通过自定义listView同时选择和搜索不起作用【英文标题】：Selecting and searching simultaneously through custom listView not working 【发布时间】：2018-11-15 13:17:26 【问题描述】：我是 android 新手，我正在开发一个购物清单应用程序，但遇到了一些麻烦。
现在，我制作了一个包含图像和名称字段的自定义列表视图。我还制作了一个填充 listViews 的自定义对象 GroceryItem。
我希望用户能够从 listView 中选择 GroceryItems，并在列表中进行搜索。这是我的 listView 的自定义适配器。
class CustomAdapter extends ArrayAdapter<GroceryItem> implements Filterable
private ArrayList<GroceryItem> mObjects;
private ArrayFilter mFilter;
private ArrayList<GroceryItem> mOriginalValues;
CustomAdapter(@NonNull Context context, int resource, @NonNull ArrayList<GroceryItem> inputValues)
super(context, resource, inputValues);
mObjects = new ArrayList<>(inputValues);
public void setBackup()
mOriginalValues = new ArrayList<GroceryItem>();
mOriginalValues.addAll(mObjects);
@SuppressLint("ClickableViewAccessibility")
@Override
public View getView(int position, View convertView, ViewGroup parent)
// Get the data item for this position
final GroceryItem currentGroceryItem = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null)
convertView = getLayoutInflater().inflate(R.layout.custom_layout, parent, false);
// Lookup view for data population
ImageView groceryImage = (ImageView) convertView.findViewById(R.id.groceryImage);
TextView groceryNameText = (TextView) convertView.findViewById(R.id.groceryName);
LinearLayout overallItem = (LinearLayout) convertView.findViewById(R.id.linearLayout);
// Populate the data into the template view using data
groceryImage.setImageResource(currentGroceryItem.getImageID());
groceryNameText.setText(currentGroceryItem.getName());
// Set onClickListener for overallItem
overallItem.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
searchBar.clearFocus();
// Changes the selection status of the GroceryItem
currentGroceryItem.toggle();
// Changes the colour of the background accordingly (to show selection)
if(currentGroceryItem.isSelected())
v.setBackgroundColor(0xFF83B5C7);
else
v.setBackgroundColor(0xFFFFFFFF);
);
// Return the completed view to render on screen
return convertView;
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////FOR SEARCH FUNCTIONALITY////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
public View getViewByPosition(int pos, ListView myListView)
final int firstListItemPosition = myListView.getFirstVisiblePosition();
final int lastListItemPosition = firstListItemPosition + myListView.getChildCount() - 1;
if (pos < firstListItemPosition || pos > lastListItemPosition )
return getView(pos, null, myListView);
else
final int childIndex = pos - firstListItemPosition;
return myListView.getChildAt(childIndex);
public void fixToggling()
runOnUiThread(new Runnable()
@Override
public void run()
for(int i = 0; i < getCount(); ++i)
// Finds view at index i in listView, which is a global variable
View view = getViewByPosition(i, listView);
if(getItem(i).isSelected())
view.setBackgroundColor(0XFF83B5C7);
else
view.setBackgroundColor(0xFFFFFFFF);
);
// The following function reverses the filter (sets everything to default)
public void reverseFilter()
//Replaces mObjects with mOriginal Values
mObjects.clear();
mObjects.addAll(mOriginalValues);
//Loads mObjects (now filled with the original items) into the adapter
this.clear();
this.addAll(mObjects);
fixToggling();
// The following function applies a filter given a query
public void applyFilter(String query)
if(query == null || query.length() == 0)
reverseFilter();
else
// Creates a new array filter
mFilter = new ArrayFilter();
// performs the filters, and publishes the result (i.e. writes the result into
// mObjects)
mFilter.publishResults(query, mFilter.performFiltering(query));
// Clears current content of the adapter
this.clear();
// Fills the adapter with the content of the filtered result
this.addAll(mObjects);
fixToggling();
private class ArrayFilter extends Filter
@Override
protected FilterResults performFiltering(CharSequence prefix)
final FilterResults results = new FilterResults();
if(mOriginalValues == null)
mOriginalValues = new ArrayList<>(mObjects);
// If there is no input query
if (prefix == null || prefix.length() == 0)
// Make a copy of mOriginalValues into the list
final ArrayList<GroceryItem> list;
list = new ArrayList<>(mOriginalValues);
// Set the FilterResults value to the copy of mOriginalValues
results.values = list;
results.count = list.size();
// If there is an input query (at least one character in length)
else
// Converts the query to a lowercase String
final String prefixString = prefix.toString().toLowerCase();
// Makes a copy of mOriginalValues into the ArrayList "values"
final ArrayList<GroceryItem> values;
values = new ArrayList<>(mOriginalValues);
final int count = values.size();
// Makes a new empty ArrayList
final ArrayList<GroceryItem> newValues = new ArrayList<>();
// Iterates through the number of elements in mOriginalValues
for (int i = 0; i < count; i++)
// Gets the GroceryItem element at position i from mOriginalValues' copy
final GroceryItem value = values.get(i);
// Extracts the name of the GroceryItem element into valueText
final String valueText = value.getName().toLowerCase();
// First match against the whole, non-splitted value
if (valueText.startsWith(prefixString))
newValues.add(value);
else
// Splits the one String into all its constituent words
final String[] words = valueText.split(" ");
// If any of the constituent words starts with the prefix, adds them
for (String word : words)
if (word.startsWith(prefixString))
newValues.add(value);
break;
// Sets the FilterResult value to the newValues ArrayList. mOriginalValues is
// preserved.
results.values = newValues;
results.count = newValues.size();
// Changes mObjects from (potentially) the original items or the previously filtered
// results to the new filtered results. Needs to be loaded into the adapter still.
mObjects.clear();
mObjects.addAll(newValues);
return results;
@Override
protected void publishResults(CharSequence constraint, FilterResults results)
notifyDataSetChanged();
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////
这是我遇到的问题。我现在有四种杂货：苹果、香蕉、葡萄和芒果。如果我选择葡萄，一切正常。它以蓝色背景显示葡萄，以白色背景显示所有其他项目。当我开始在搜索栏中输入“gr”时，一切正常。我只看到葡萄，并且该项目显示为选中（蓝色背景）。当我输入“grm”时，一切都消失了，没有任何选择。但是，当我退格一个字符并返回“gr”时，它向我显示葡萄，但它不再被选中。
另一个类似的问题。再次从 Apple、Banana、Grapes 和 Mango 开始，如果我选择 Grapes 并搜索“b”，我会发现 Banana 未选中。伟大的。现在，当我选择香蕉时，它显示为已选中。但是，一旦我退格，我就会返回到完整的项目列表，并且只选择了葡萄。
我编写了 fixToggling() 函数来遍历每个视图并根据需要修复背景颜色。我还进行了一些调试，以了解每个groceryItem 中的isSelected 布尔值被正确记录，因此应用程序不记得哪些应该被选中或不应该被选中不是问题。出于某种原因，切换刚刚关闭。
有人可以帮忙吗？我只想让用户同时使用搜索功能和项目选择。
【问题讨论】：
【参考方案1】：试试这个适配器代码：
class CustomAdapter2 extends ArrayAdapter<GroceryItem> implements Filterable
private ArrayList<GroceryItem> mObjects;
private ArrayList<GroceryItem> mOriginalValues;
private ArrayFilter mFilter;
private LayoutInflater mLayoutInflater;
CustomAdapter2(@NonNull Context context, int resource, @NonNull ArrayList<GroceryItem> inputValues)
super(context, resource, inputValues);
mLayoutInflater = LayoutInflater.from(context);
mObjects = inputValues;
public void setBackup()
mOriginalValues = new ArrayList<>();
mOriginalValues.addAll(mObjects);
@SuppressLint("ClickableViewAccessibility")
@Override
public View getView(int position, View convertView, ViewGroup parent)
// Get the data item for this position
GroceryItem currentGroceryItem = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null)
convertView = mLayoutInflater.inflate(R.layout.custom_layout, parent, false);
// Lookup view for data population
ImageView groceryImage = (ImageView) convertView.findViewById(R.id.groceryImage);
TextView groceryNameText = (TextView) convertView.findViewById(R.id.groceryName);
LinearLayout overallItem = (LinearLayout) convertView.findViewById(R.id.linearLayout);
// Populate the data into the template view using data
groceryImage.setImageResource(currentGroceryItem.getImageID());
groceryNameText.setText(currentGroceryItem.getName());
if(currentGroceryItem.isSelected())
overallItem.setBackgroundColor(0xFF83B5C7);
else
overallItem.setBackgroundColor(0xFFFFFFFF);
// Set onClickListener for overallItem
overallItem.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
int pos = (int)v.getTag();
GroceryItem currentGroceryItem = getItem(pos);
searchBar.clearFocus();
// Changes the selection status of the GroceryItem
currentGroceryItem.toggle();
// Changes the colour of the background accordingly (to show selection)
if(currentGroceryItem.isSelected())
v.setBackgroundColor(0xFF83B5C7);
else
v.setBackgroundColor(0xFFFFFFFF);
);
// Return the completed view to render on screen
convertView.setTag(position);
return convertView;
/////////////////////////////////FOR SEARCH FUNCTIONALITY///////////////////////////////////
@NonNull
@Override
public Filter getFilter()
if(mFilter == null)
// Make a backup copy of list
setBackup();
mFilter = new ArrayFilter();
return mFilter;
private class ArrayFilter extends Filter
@Override
protected FilterResults performFiltering(CharSequence prefix)
FilterResults results = new FilterResults();
ArrayList<GroceryItem> list = new ArrayList<>();
// If there is no input query
if (prefix == null || prefix.length() == 0)
// Set the FilterResults value to the copy of mOriginalValues
list = new ArrayList<>(mOriginalValues);
// If there is an input query (at least one character in length)
else
// Converts the query to a lowercase String
String prefixString = prefix.toString().toLowerCase();
// Iterates through the number of elements in mOriginalValues
for (int i = 0; i < mOriginalValues.size(); i++)
// Gets the GroceryItem element at position i from mOriginalValues' copy
GroceryItem value = mOriginalValues.get(i);
// Extracts the name of the GroceryItem element into valueText
String valueText = value.getName().toLowerCase();
// First match against the whole, non-splitted value
if (valueText.startsWith(prefixString))
list.add(value);
else
// Splits the one String into all its constituent words
String[] words = valueText.split(" ");
// If any of the constituent words starts with the prefix, adds them
for (String word : words)
if (word.startsWith(prefixString))
list.add(value);
break;
// Sets the FilterResult value to list ArrayList.
results.values = list;
results.count = list.size();
return results;
@Override
protected void publishResults(CharSequence constraint, FilterResults results)
clear();
addAll((ArrayList<GroceryItem>)results.values);
notifyDataSetChanged();
////////////////////////////////////////////////////////////////////////////////////////////
希望有帮助！
【讨论】：
这正是我想要的！！非常感谢你的帮助！我看到了您的代码，并看到了您在 OnClickListener 和 getView 中所做的修复。你能解释一下这些变化，这样我就不会再重复我的错误了吗？再次感谢您！ 1.您的主要问题是您仅在 onClick() 中更改了视图背景颜色。所以对于过滤，视图重绘但不会相应地改变颜色。 2. 我不使用最终变量，而是使用 setTag() 方法通过可点击视图传递位置。理论上，最终变量应该可以工作，但我很久以前就看到过一个使用最终变量的问题。改成 setTag() 方法后解决。因此，我继续将它用于 ListView。这种改变可能是不必要的。我关于 ListView 的博客：programandroidlistview.blogspot.com以上是关于通过自定义listView同时选择和搜索不起作用的主要内容，如果未能解决你的问题，请参考以下文章
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