一手遮天 Android - view（文本类）: MultiAutoCompleteTextView 基础
示例如下:
/view/text/MultiAutoCompleteTextViewDemo1.java
/**
* MultiAutoCompleteTextView - 自动完成文本框（支持多选），MultiAutoCompleteTextView 继承自 AutoCompleteTextView
* 与 AutoCompleteTextView 不同的是，MultiAutoCompleteTextView 支持多选，需要通过 setTokenizer() 指定分隔符（不指定则不工作）
*
* 本例演示
* 1、如何通过 ArrayAdapter 绑定数据和模板
* 2、如何通过自定义的 BaseAdapter 并实现 Filterable 接口来绑定数据和模板
* 3、如何监听下拉列表的点击事件，并获取选中项的数据对象
*/
package com.webabcd.androiddemo.view.text;
import android.content.Context;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.MultiAutoCompleteTextView;
import android.widget.TextView;
import com.webabcd.androiddemo.R;
import java.util.ArrayList;
import java.util.List;
public class MultiAutoCompleteTextViewDemo1 extends AppCompatActivity {
private MultiAutoCompleteTextView mMultiAutoCompleteTextView1;
private MultiAutoCompleteTextView mMultiAutoCompleteTextView2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_text_multiautocompletetextviewdemo1);
mMultiAutoCompleteTextView1 = findViewById(R.id.multiAutoCompleteTextView1);
mMultiAutoCompleteTextView2 = findViewById(R.id.multiAutoCompleteTextView2);
sample1();
sample2();
}
// 通过 ArrayAdapter 绑定数据和模板
private void sample1() {
String[] data = new String[]{"abc", "abcd", "abcde", "abcdef", "abcdefg"};
mMultiAutoCompleteTextView1.setAdapter(new ArrayAdapter<String>(MultiAutoCompleteTextViewDemo1.this, android.R.layout.simple_dropdown_item_1line, data));
// 指定分隔符（不指定则不工作）
mMultiAutoCompleteTextView1.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());
}
// 通过自定义的 BaseAdapter 并实现 Filterable 接口来绑定数据和模板
private void sample2() {
// 构造数据
final List<MyData> myDataList = new ArrayList<MyData>();
myDataList.add(new MyData("abc", "abc"));
myDataList.add(new MyData("abcd", "abcd"));
myDataList.add(new MyData("abcde", "abcde"));
myDataList.add(new MyData("abcdef", "abcdef"));
myDataList.add(new MyData("abcdefg", "abcdefg"));
// 实例化自定义的 BaseAdapter（注：为 MultiAutoCompleteTextView 提供数据必须要实现 Filterable 接口）
final MyAdapter myAdapter = new MyAdapter(myDataList, this);
mMultiAutoCompleteTextView2.setAdapter(myAdapter);
// 指定分隔符（不指定则不工作）
mMultiAutoCompleteTextView2.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());
// 点击了下拉列表中的某一项时的事件
mMultiAutoCompleteTextView2.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// 下面这个获取的不是选中项的对象
// MyData myData = myDataList.get(position);
// 下面这个获取的才是选中项的对象
MyData myData = (MyData) parent.getItemAtPosition(position);
}
});
}
// 自定义实体类
class MyData {
private String _name;
private String _comment;
public MyData() {
}
public MyData( String name, String comment) {
this._name = name;
this._comment = comment;
}
public String getName() {
return _name;
}
public String getComment() {
return _comment;
}
public void setName(String name) {
this._name = name;
}
public void setComment(String comment) {
this._comment = comment;
}
// 选中下拉列表的某一项后，将调用此项对应的对象的 toString() 方法，并将其结果赋值给 MultiAutoCompleteTextView 文本框
// 所以如果绑定的数据是自定义对象的话，要重写其 toString() 方法，以便在 MultiAutoCompleteTextView 的文本框中显示合适的值
@Override
public String toString() {
return _name;
}
}
// 自定义 BaseAdapter，并实现 Filterable 接口（注：绑定到 MultiAutoCompleteTextView 时，必须要实现 Filterable 接口）
class MyAdapter extends BaseAdapter implements Filterable {
private List<MyData> _myDataListOriginal; // 原始数据
private List<MyData> _myDataListFiltered; // 筛选后的数据（下拉列表需要显示的数据）
private Context _context;
public MyAdapter(List<MyData> myDataList, Context context) {
this._myDataListFiltered = new ArrayList<MyData>();
this._myDataListOriginal = myDataList;
this._context = context;
}
@Override
public int getCount() {
return _myDataListFiltered.size();
}
@Override
public Object getItem(int position) {
return _myDataListFiltered.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
convertView = LayoutInflater.from(_context).inflate(R.layout.item_view_text_multiautocompletetextviewdemo1, parent, false);
holder = new ViewHolder();
holder.txtName = (TextView) convertView.findViewById(R.id.txtName);
holder.txtComment = (TextView) convertView.findViewById(R.id.txtComment);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.txtName.setText(_myDataListFiltered.get(position).getName());
holder.txtComment.setText(_myDataListFiltered.get(position).getComment());
return convertView;
}
// 实现 Filterable 接口
@Override
public Filter getFilter() {
Filter filter = new Filter() {
/**
* 删选出符合条件的数据的集合
* @param constraint 用户输入的数据
*/
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
List<MyData> list = new ArrayList<>();
if(constraint != null){
for (MyData myData : _myDataListOriginal) {
if (myData.getName().contains(constraint)) {
list.add(myData);
}
}
}
// 符合条件的数据的数量
results.count = list.size();
// 符合条件的数据的集合
results.values = list;
return results;
}
/**
* 筛选逻辑执行完毕
* @param constraint 用户输入的数据
* @param results 由 performFiltering() 返回的筛选结果
*/
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
// 更新下拉框需要显示的数据
_myDataListFiltered = (List<MyData>) results.values;
// 刷新下拉框
notifyDataSetChanged();
}
};
return filter;
}
class ViewHolder {
TextView txtName;
TextView txtComment;
}
}
}
/layout/activity_view_text_multiautocompletetextviewdemo1.xml
<?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">
<!--
completionHint/completionHintView - 下拉列表中的提示标题
completionThreshold - 指定至少输入多少字符后才会弹出下拉列表（默认值为 2）
dropDownWidth/dropDownHeight - 下拉列表的宽度和高度
dropDownHorizontalOffset/dropDownVerticalOffset - 下拉列表的水平偏移和垂直偏移
dropDownAnchor - 下拉列表显示位置关联的组件（默认是自己，也可以通过 @id/xxx 来指定）
dropDownSelector - 下拉列表中的某一项被点击后的背景
-->
<MultiAutoCompleteTextView
android:id="@+id/multiAutoCompleteTextView1"
android:layout_width="match_parent"
android:layout_height="48dp"
android:completionHint="建议列表"
android:completionThreshold="2"
android:dropDownSelector="@color/red" />
<MultiAutoCompleteTextView
android:id="@+id/multiAutoCompleteTextView2"
android:layout_width="match_parent"
android:layout_height="48dp"
android:completionHint="建议列表"
android:completionThreshold="1"
android:dropDownSelector="@color/orange" />
</LinearLayout>
/layout/item_view_text_multiautocompletetextviewdemo1.xml
<?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">
<TextView
android:id="@+id/txtName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#1D1D1D"
android:textSize="24sp" />
<TextView
android:id="@+id/txtComment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#B4B4B4"
android:textSize="14sp" />
</LinearLayout>