我一直在研究AutoCompleteTextView。当我们键入时，我能够在下拉列表中获得建议和所有内容。
我的问题是：我们可以在建议下拉列表中突出显示输入的字符吗？
【问题讨论】：
标签： android android-listview android-ui autocompletetextview
我已经实现了功能。解决方法如下：
AutoCompleteAdapter.java
public class AutoCompleteAdapter extends ArrayAdapter<String> implements
Filterable {
private ArrayList<String> fullList;
private ArrayList<String> mOriginalValues;
private ArrayFilter mFilter;
LayoutInflater inflater;
String text = "";
public AutoCompleteAdapter(Context context, int resource,
int textViewResourceId, List<String> objects) {
super(context, resource, textViewResourceId, objects);
fullList = (ArrayList<String>) objects;
mOriginalValues = new ArrayList<String>(fullList);
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return fullList.size();
}
@Override
public String getItem(int position) {
return fullList.get(position);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
// tvViewResourceId = (TextView) view.findViewById(android.R.id.text1);
String item = getItem(position);
Log.d("item", "" + item);
if (convertView == null) {
convertView = view = inflater.inflate(
android.R.layout.simple_dropdown_item_1line, null);
}
// Lookup view for data population
TextView myTv = (TextView) convertView.findViewById(android.R.id.text1);
myTv.setText(highlight(text, item));
return view;
}
@Override
public Filter getFilter() {
if (mFilter == null) {
mFilter = new ArrayFilter();
}
return mFilter;
}
private class ArrayFilter extends Filter {
private Object lock;
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (prefix != null) {
text = prefix.toString();
}
if (mOriginalValues == null) {
synchronized (lock) {
mOriginalValues = new ArrayList<String>(fullList);
}
}
if (prefix == null || prefix.length() == 0) {
synchronized (lock) {
ArrayList<String> list = new ArrayList<String>(
mOriginalValues);
results.values = list;
results.count = list.size();
}
} else {
final String prefixString = prefix.toString().toLowerCase();
ArrayList<String> values = mOriginalValues;
int count = values.size();
ArrayList<String> newValues = new ArrayList<String>(count);
for (int i = 0; i < count; i++) {
String item = values.get(i);
if (item.toLowerCase().contains(prefixString)) {
newValues.add(item);
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
if (results.values != null) {
fullList = (ArrayList<String>) results.values;
} else {
fullList = new ArrayList<String>();
}
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
public static CharSequence highlight(String search, String originalText) {
// ignore case and accents
// the same thing should have been done for the search text
String normalizedText = Normalizer
.normalize(originalText, Normalizer.Form.NFD)
.replaceAll("\\p{InCombiningDiacriticalMarks}+", "")
.toLowerCase(Locale.ENGLISH);
int start = normalizedText.indexOf(search.toLowerCase(Locale.ENGLISH));
if (start < 0) {
// not found, nothing to to
return originalText;
} else {
// highlight each appearance in the original text
// while searching in normalized text
Spannable highlighted = new SpannableString(originalText);
while (start >= 0) {
int spanStart = Math.min(start, originalText.length());
int spanEnd = Math.min(start + search.length(),
originalText.length());
highlighted.setSpan(new ForegroundColorSpan(Color.BLUE),
spanStart, spanEnd, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
start = normalizedText.indexOf(search, spanEnd);
}
return highlighted;
}
}
}
MainActivity.java
public class MainActivity extends Activity {
String[] languages = { "C", "C++", "Java", "C#", "PHP", "JavaScript",
"jQuery", "AJAX", "JSON" };
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
List<String> wordList = new ArrayList<String>();
Collections.addAll(wordList, languages);
AutoCompleteAdapter adapter = new AutoCompleteAdapter(this,
android.R.layout.simple_dropdown_item_1line,
android.R.id.text1,wordList);
AutoCompleteTextView acTextView = (AutoCompleteTextView) findViewById(R.id.languages);
acTextView.setThreshold(1);
acTextView.setAdapter(adapter);
}
}
像魅力一样工作！
享受吧！
【讨论】：
java @Override public void clear() { super.clear(); fullList.clear(); mOriginalValues.clear(); } @Override public void addAll(@NonNull Collection<? extends String> collection) { super.addAll(collection); fullList.addAll(collection); mOriginalValues.addAll(fullList); } 下面的行
getView 和hightlight 实现自定义适配器就足够了。您可以从AutocompleteTextView 获取当前文本。此外，这个highlight 实现将提高所有发生率，如果您只想要第一个，那么只需省略while 循环。
AutoCompleteAdapter 中包含对android.R.layout.simple_dropdown_item_1line 和android.R.id.text1 的引用，您应该定义自己的以自定义文本颜色（请参阅stackoverflow.com/questions/12876840/...）。它也不支持单击下拉列表（请参阅stackoverflow.com/questions/15544943/...）。请参阅stackoverflow.com/a/62091157/2914140 的解决方案。
我认为这应该是可能的，前提是您知道用户最后键入的字符的索引/索引。然后，您可以使用SpannableStringBuilder 并设置ForegroundColorSpan 和BackgroundColorSpan 以使角色具有高亮的外观。
这个想法有点像这样：
// start & end of the highlight
int start = ...;
int end = ...;
SpannableStringBuilder builder = new SpannableStringBuilder(suggestionText);
// set foreground color (text color) - optional, you may not want to change the text color too
builder.setSpan(new ForegroundColorSpan(Color.RED), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
// set background color
builder.setSpan(new BackgroundColorSpan(Color.YELLOW), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
// set result to AutoCompleteTextView
autocompleteTextview.setText(builder);
请注意，只要您不输入其他字符，“突出显示”就会一直存在。例如，您可能希望删除突出显示。用户更改AutoCompleteTextView 中的光标位置，但我将由您决定。
【讨论】：
我知道现在回答这个问题已经太晚了，但是由于我个人努力寻找答案，最后我自己写了它（在@MH.ofcourse的答案的帮助下），所以这里是：
首先，您必须创建一个自定义 ArrayAdapter：
public class AdapterAustocomplete extends ArrayAdapter<String> {
private static final String TAG = "AdapterAustocomplete";
String q = "";
public AdapterAustocomplete(Context context, int resource, List objects) {
super(context, resource, objects);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
String item = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
convertView =
// I'll use a custom view for each Item , this way I can customize it also!
G.inflater.from(getContext()).inflate(R.layout.textview_autocomplete, parent, false);
}
// Lookup view for data population
TextView myTv = (TextView) convertView.findViewById(R.id.txt_autocomplete);
int start = item.indexOf(q);
int end = q.length()+start;
SpannableStringBuilder builder = new SpannableStringBuilder(item);
builder.setSpan(new ForegroundColorSpan(Color.RED), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
myTv.setText(builder);
return convertView;
}
public void setQ(String q) {
this.q = q;
}
}
并且在您要设置 AutoCompleteTextView 适配器的代码中；
AutoCompleteTextView myAutoComplete = findViewById(its_id);
AdapterAustocomplete adapter_autoComplete = new AdapterAustocomplete(getActivity(), 0, items); // items is an arrayList of Strings
adapter_autoComplete.setQ(q);
myAutoComplete.setAdapter(adapter_autoComplete);
【讨论】：
感谢vadher jitendra我写了同样的东西并修复了一些错误。
将下拉布局更改为拥有。
添加在AutoCompleteTextView 内部单击时显示完整列表。
修复了显示时冻结列表的错误（在highlight中添加了对空字符串的检查）。
row_dropdown.xml（项目布局）：
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/text1"
style="?android:attr/dropDownItemStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:ellipsize="marquee"
android:paddingTop="8dp"
android:paddingBottom="8dp"
android:singleLine="true"
android:textColor="#333333"
android:textSize="15sp"
tools:text="text"
tools:textAppearance="?android:attr/textAppearanceLargePopupMenu" />
要在键入时过滤列表，我们应该实现 ArrayAdapter。这取决于项目（T 类）。您可以稍后使用AutoCompleteAdapter<String> 或您喜欢的任何数据类。
自动完成适配器：
import android.content.Context;
import android.graphics.Typeface;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.StyleSpan;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;
import androidx.annotation.IdRes;
import androidx.annotation.LayoutRes;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
public class AutoCompleteAdapter<T> extends ArrayAdapter<T> implements Filterable {
private Context context;
@LayoutRes
private int layoutRes;
@IdRes
private int textViewResId;
private ArrayList<T> fullList;
private ArrayList<T> originalValues;
private ArrayFilter filter;
private LayoutInflater inflater;
private String query = "";
public AutoCompleteAdapter(@NonNull Context context, @LayoutRes int resource, @IdRes int textViewResourceId, @NonNull List<T> objects) {
super(context, resource, textViewResourceId, objects);
this.context = context;
layoutRes = resource;
textViewResId = textViewResourceId;
fullList = (ArrayList<T>) objects;
originalValues = new ArrayList<>(fullList);
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return fullList.size();
}
@Override
public T getItem(int position) {
return fullList.get(position);
}
/**
* You can use either
* vadher jitendra method (getView)
* or get the method from ArrayAdapter.java.
*/
// @NotNull
// @Override
// public View getView(int position, View convertView, ViewGroup parent) {
// View view = convertView;
// T item = getItem(position);
// Log.d("item", "" + item);
// if (convertView == null) {
// convertView = view = inflater.inflate(layoutRes, null);
// }
// // Lookup view for data population
// TextView myTv = convertView.findViewById(textViewResId);
// myTv.setText(highlight(query, item));
// return view;
// }
@Override
public @NonNull
View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
return createViewFromResource(inflater, position, convertView, parent, layoutRes);
}
private @NonNull
View createViewFromResource(@NonNull LayoutInflater inflater, int position,
@Nullable View convertView, @NonNull ViewGroup parent, int resource) {
final View view;
final TextView text;
if (convertView == null) {
view = inflater.inflate(resource, parent, false);
} else {
view = convertView;
}
try {
if (textViewResId == 0) {
// If no custom field is assigned, assume the whole resource is a TextView
text = (TextView) view;
} else {
// Otherwise, find the TextView field within the layout
text = view.findViewById(textViewResId);
if (text == null) {
throw new RuntimeException("Failed to find view with ID "
+ context.getResources().getResourceName(textViewResId)
+ " in item layout");
}
}
} catch (ClassCastException e) {
Log.e("ArrayAdapter", "You must supply a resource ID for a TextView");
throw new IllegalStateException(
"ArrayAdapter requires the resource ID to be a TextView", e);
}
final T item = getItem(position);
text.setText(highlight(query, item.toString()));
// if (item instanceof CharSequence) {
// text.setText(highlight(query, (CharSequence) item));
// } else {
// text.setText(item.toString());
// }
return view;
}
@Override
public @NonNull
Filter getFilter() {
if (filter == null) {
filter = new ArrayFilter();
}
return filter;
}
private class ArrayFilter extends Filter {
private final Object lock = new Object();
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (prefix == null) {
query = "";
} else {
query = prefix.toString();
}
if (originalValues == null) {
synchronized (lock) {
originalValues = new ArrayList<>(fullList);
}
}
if (prefix == null || prefix.length() == 0) {
synchronized (lock) {
ArrayList<T> list = new ArrayList<>(originalValues);
results.values = list;
results.count = list.size();
}
} else {
final String prefixString = prefix.toString().toLowerCase();
ArrayList<T> values = originalValues;
int count = values.size();
ArrayList<T> newValues = new ArrayList<>(count);
for (int i = 0; i < count; i++) {
T item = values.get(i);
if (item.toString().toLowerCase().contains(prefixString)) {
newValues.add(item);
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
if (results.values != null) {
fullList = (ArrayList<T>) results.values;
} else {
fullList = new ArrayList<>();
}
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
private static CharSequence highlight(@NonNull String search, @NonNull CharSequence originalText) {
if (search.isEmpty())
return originalText;
// ignore case and accents
// the same thing should have been done for the search text
String normalizedText = Normalizer
.normalize(originalText, Normalizer.Form.NFD)
.replaceAll("\\p{InCombiningDiacriticalMarks}+", "")
.toLowerCase(Locale.ENGLISH);
int start = normalizedText.indexOf(search.toLowerCase(Locale.ENGLISH));
if (start < 0) {
// not found, nothing to do
return originalText;
} else {
// highlight each appearance in the original text
// while searching in normalized text
Spannable highlighted = new SpannableString(originalText);
while (start >= 0) {
int spanStart = Math.min(start, originalText.length());
int spanEnd = Math.min(start + search.length(),
originalText.length());
highlighted.setSpan(new StyleSpan(Typeface.BOLD), spanStart, spanEnd, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
start = normalizedText.indexOf(search, spanEnd);
}
return highlighted;
}
}
}
为了在单击AutoCompleteTextView 时显示下拉列表，我们需要覆盖setOnTouchListener，如https://stackoverflow.com/a/26036902/2914140 中所述。 Lint 也会打印警告，所以我们必须编写一个自定义视图：
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import androidx.appcompat.widget.AppCompatAutoCompleteTextView;
/*
Avoids a warning "Custom view `AutoCompleteTextView` has setOnTouchListener called on it but does not override performClick".
*/
public class AutoCompleteTV extends AppCompatAutoCompleteTextView {
public AutoCompleteTV(Context context) {
super(context);
}
public AutoCompleteTV(Context context, AttributeSet attrs) {
super(context, attrs);
}
public AutoCompleteTV(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
performClick();
}
return super.onTouchEvent(event);
}
@Override
public boolean performClick() {
super.performClick();
return true;
}
}
然后在activity_main.xml中使用：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.textfield.TextInputLayout
style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.example.autocompletetextview1.AutoCompleteTV
android:id="@+id/languages"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:completionThreshold="1"
android:hint="language"
android:imeOptions="actionNext"
android:maxLines="1"
android:paddingLeft="10dp"
android:paddingTop="15dp"
android:paddingRight="10dp"
android:paddingBottom="15dp"
android:singleLine="true"
android:textColor="#333333"
android:textColorHint="#808080"
android:textSize="12sp" />
</com.google.android.material.textfield.TextInputLayout>
</LinearLayout>
我这里使用TextInputLayout是为了更好的装饰，在这种情况下我们必须添加Material Design Components：
在 build.gradle 中：
implementation 'com.google.android.material:material:1.3.0-alpha01'
在styles.xml中：
<style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
...
主活动：
import android.os.Bundle;
import android.view.MotionEvent;
import android.widget.AutoCompleteTextView;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
String[] items = {"C", "C++", "Java", "C#", "PHP", "JavaScript", "jQuery", "AJAX", "JSON"};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<DataClass> wordList = new ArrayList<>();
for (int i = 0; i < items.length; i++) {
DataClass data = new DataClass(i, items[i]);
wordList.add(data);
}
AutoCompleteAdapter<DataClass> adapter = new AutoCompleteAdapter<>(this,
R.layout.row_dropdown, R.id.text1, wordList);
//adapter.setDropDownViewResource(R.layout.row_dropdown);
AutoCompleteTV acTextView = findViewById(R.id.languages);
acTextView.setThreshold(1);
acTextView.setAdapter(adapter);
acTextView.setText("Java");
acTextView.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
((AutoCompleteTextView) v).showDropDown();
v.requestFocus();
v.performClick(); // Added to avoid warning "onTouch lambda should call View#performClick when a click is detected".
}
return false;
}
);
}
}
【讨论】：