AutoTextView自定义自动提示
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我们知道，要为AutoTextView添加自动提示，只需要为它设置一个ArrayAdapter适配器就可以了，我们开始使用这样的构造方法new ArrayAdapter(context, R.id.list_item, strArray);然后为AutoTextView设置适配器即可
我来说明一下ArrayAdapter的参数，第一个context不言而喻，我们传入当前activity.this即可
第二个是每条提示的样式，第三个是一个字符串数组，表明提示内容
我们通过传入strArray，就可以设置提示，但是这样不够灵活，如果我们要特别的需求，例如只提示与输入相关的内容，我们应该怎么做呢？
其实 ArrayAdapter是集成baseAdapdter的，我们也可以自己写一个适配器，类似ArrayAdapter的写法即可
下面的代码，主要说明复写的原理
class AutoTextViewAdapter<T> extends BaseAdapter implements Filterable{
Filter mFilter = new ArrayFilter();
private List<T> mObjects;
private int mResource;
private LayoutInflater mInflater;
private int mDropDownResource;
Context mContext;
private int mFieldId = 0;//下拉框选项ID
public AutoTextViewAdapter(Context context,int resource,int textViewResourceId,T[] objects) {
init(context, resource, textViewResourceId, objects);
}
public void init(Context context,int resource,int textViewResourceId,T[] objects){
mContext = context;
mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mResource = mDropDownResource = resource;
mFieldId = textViewResourceId;
mObjects = Arrays.asList(objects);
}
@Override
public int getCount() {
return mObjects.size();
}
@Override
public T getItem(int position) {
return mObjects.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
return creatDropDownView(position, convertView,parent,mResource);
}
public View creatDropDownView(int position, View convertView,ViewGroup parent,int resource){
View view;
TextView text;
if (convertView == null) {
view = mInflater.inflate(resource, parent, false);
} else {
view = convertView;
}
try {
if (mFieldId == 0) {
text = (TextView) view;
} else {
text = (TextView) view.findViewById(mFieldId);
}
} 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);
}
T item = getItem(position);
if (item instanceof CharSequence) {
text.setText((CharSequence)item);
} else {
text.setText(item.toString());
}
return view;
}
@Override
public Filter getFilter() {
if (mFilter == null) {
mFilter = new ArrayFilter();
}
return mFilter;
}
public void setDropDownViewResource(int resource){
this.mDropDownResource = resource;
}
@Override
public View getDropDownView(int position, View convertView,ViewGroup parent) {
System.out.println("ss");
return creatDropDownView(position, convertView,parent,mDropDownResource);
}
class ArrayFilter extends Filter{
@Override
protected FilterResults performFiltering(CharSequence arg0) {
FilterResults results = new FilterResults();//创建FilterResults对象
final ArrayList<T> newValues = new ArrayList<T>(1);
newValues.add((T)("aaa"));
newValues.add((T)("bbb"));
newValues.add((T)("ccc"));
newValues.add((T)("ddd"));
results.values = newValues;
results.count = newValues.size();
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
mObjects = (List<T>) results.values;
notifyDataSetChanged();
}
}
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
GGView.enable=false;
System.exit(0);
}
return true;
}
我说明我们要实现自动提示效果，需要哪些必要步骤
1，要继承baseApadter，与Filterable接口，复写他们的方法
2，在构造方法里面 AutoTextViewAdapter(Context context,int resource,T[] objects)
resource是每条提示的样式，objects是输入的内容，你可以查看ArrayAdapter就知道他们的用处了，当然objects可以不传，但是传进去，是为了过滤需要，例如我传进去一个“广”，那么我们就可以利用这个参数来确定内容，例如我在数据库里面，只取以“广”开头的内容
3，baseAdapter的四个方法必须重写，所以我在类里面增加了一个List<T> mObjects，这个是用来存储处理后的提示结果数组的。特别是getView方法，其实就是方法返回提示框view，因为public View getView(int position, View convertView, ViewGroup parent) 里面有个参数parent，所以我们在这个方法里面，每次只要返回一条提示的样式内容，就会结合parent,构成完整的样式
4，ArrayFilter extends Filter必须含有这个内部类，实现performFiltering方法，我们运行适配器时，首先就会运行这个方法，所以在这里我们处理处提示数据，将他们装载在 mObjects里面
publishResults方法，会获取performFiltering的返回值，我们在这里可以做别的处理，例如把返回值付给 mObjects，使用notifyDataSetChanged()提示UI变化等
下面贴一个完整的实例代码，大家可以copy下来研究
package com.example.androidtest;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AutoCompleteTextView;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;
public class MainActivity extends Activity{
private AutoCompleteTextView aTextView = null;
private AutoTextViewAdapter<String> aTextViewAdapter = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
aTextView = (AutoCompleteTextView) findViewById(R.id.EditText11);
String[] str= {"sss","aaa","vvvv"};
aTextViewAdapter = new AutoTextViewAdapter<String>(this,R.layout.list_item,0,str);
aTextView.setAdapter(aTextViewAdapter);
//aTextView.setDropDownHeight(100) ;
}
class AutoTextViewAdapter<T> extends BaseAdapter implements Filterable{
Filter mFilter = new ArrayFilter();
private List<T> mObjects;
private int mResource;
private LayoutInflater mInflater;
private int mDropDownResource;
Context mContext;
private int mFieldId = 0;//下拉框选项ID
public AutoTextViewAdapter(Context context,int resource,int textViewResourceId,T[] objects) {
init(context, resource, textViewResourceId, objects);
}
public void init(Context context,int resource,int textViewResourceId,T[] objects){
mContext = context;
mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mResource = mDropDownResource = resource;
mFieldId = textViewResourceId;
mObjects = Arrays.asList(objects);
}
@Override
public int getCount() {
return mObjects.size();
}
@Override
public T getItem(int position) {
return mObjects.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
return creatDropDownView(position, convertView,parent,mResource);
}
public View creatDropDownView(int position, View convertView,ViewGroup parent,int resource){
View view;
TextView text;
if (convertView == null) {
view = mInflater.inflate(resource, parent, false);
} else {
view = convertView;
}
try {
if (mFieldId == 0) {
text = (TextView) view;
} else {
text = (TextView) view.findViewById(mFieldId);
}
} 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);
}
T item = getItem(position);
if (item instanceof CharSequence) {
text.setText((CharSequence)item);
} else {
text.setText(item.toString());
}
return view;
}
@Override
public Filter getFilter() {
if (mFilter == null) {
mFilter = new ArrayFilter();
}
return mFilter;
}
public void setDropDownViewResource(int resource){
this.mDropDownResource = resource;
}
@Override
public View getDropDownView(int position, View convertView,ViewGroup parent) {
System.out.println("ss");
return creatDropDownView(position, convertView,parent,mDropDownResource);
}
class ArrayFilter extends Filter{
@Override
protected FilterResults performFiltering(CharSequence arg0) {
FilterResults results = new FilterResults();//创建FilterResults对象
final ArrayList<T> newValues = new ArrayList<T>(1);
newValues.add((T)("aaa"));
newValues.add((T)("bbb"));
newValues.add((T)("ccc"));
newValues.add((T)("ddd"));
results.values = newValues;
results.count = newValues.size();
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
mObjects = (List<T>) results.values;
notifyDataSetChanged();
}
}
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
GGView.enable=false;
System.exit(0);
}
return true;
}
}
main
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ffffff">
<AutoCompleteTextView
android:id="@+id/EditText11"
android:singleLine="true"
android:layout_marginRight="30dp"
android:layout_width="fill_parent"
android:layout_height="40dip"
android:completionThreshold="1"
android:hint="输入站名"
android:text=""/>
</LinearLayout>
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ffffff"
android:padding="10dp"
android:textSize="16sp"
android:textColor="#000000">
</TextView>