android中AutoCompleteTextView的简单用法(实现搜索历史)
网上有不少教程,那个提示框字符集都是事先写好的,例如用一个String[] 数组去包含了这些数据,但是,我们也可以吧用户输入的作为历史记录保存
下面先上我写的代码:
import android.app.Activity; import android.content.SharedPreferences; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.view.View.OnFocusChangeListener; import android.widget.ArrayAdapter; import android.widget.AutoCompleteTextView; import android.widget.Button; public class Read_historyActivity extends Activity implements OnClickListener { private AutoCompleteTextView autoTv; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); autoTv = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView1); initAutoComplete("history",autoTv); Button search = (Button) findViewById(R.id.button1); search.setOnClickListener(this); } @Override public void onClick(View v) { // 这里可以设定:当搜索成功时,才执行保存操作 saveHistory("history",autoTv); } /** * 初始化AutoCompleteTextView,最多显示5项提示,使 * AutoCompleteTextView在一开始获得焦点时自动提示 * @param field 保存在sharedPreference中的字段名 * @param auto 要操作的AutoCompleteTextView */ private void initAutoComplete(String field,AutoCompleteTextView auto) { SharedPreferences sp = getSharedPreferences("network_url", 0); String longhistory = sp.getString("history", "nothing"); String[] hisArrays = longhistory.split(","); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, hisArrays); //只保留最近的50条的记录 if(hisArrays.length > 50){ String[] newArrays = new String[50]; System.arraycopy(hisArrays, 0, newArrays, 0, 50); adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, newArrays); } auto.setAdapter(adapter); auto.setDropDownHeight(350); auto.setThreshold(1); auto.setCompletionHint("最近的5条记录"); auto.setOnFocusChangeListener(new OnFocusChangeListener() { @Override public void onFocusChange(View v, boolean hasFocus) { AutoCompleteTextView view = (AutoCompleteTextView) v; if (hasFocus) { view.showDropDown(); } } }); } /** * 把指定AutoCompleteTextView中内容保存到sharedPreference中指定的字符段 * @param field 保存在sharedPreference中的字段名 * @param auto 要操作的AutoCompleteTextView */ private void saveHistory(String field,AutoCompleteTextView auto) { String text = auto.getText().toString(); SharedPreferences sp = getSharedPreferences("network_url", 0); String longhistory = sp.getString(field, "nothing"); if (!longhistory.contains(text + ",")) { StringBuilder sb = new StringBuilder(longhistory); sb.insert(0, text + ","); sp.edit().putString("history", sb.toString()).commit(); } <span style="font-family: monospace; white-space: pre; background-color: rgb(240, 240, 240); "> } }</span>
上面的代码我实现了autocomplettextview的从sharepreference中读取历史记录并显示的功能,当没有任何输入时,提示最新的5项历史记录(这里可以加个条件,当有历史记录时才显示)
补上布局的代码
<?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"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> <LinearLayout android:layout_width="0px" android:layout_height="0px" android:focusable="true" android:focusableInTouchMode="true"></LinearLayout> <AutoCompleteTextView android:hint="请输入文字进行搜索" android:layout_height="wrap_content" android:layout_width="match_parent" android:id="@+id/autoCompleteTextView1"> </AutoCompleteTextView> <Button android:text="搜索" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> </LinearLayout>
当之有一个edittext或者auto的时候,进入画面时是默认得到焦点的,要想去除焦点,可以在auto之前加一个o像素的layout,并设置他先得到焦点。
效果图如下
下面出现的是源码内容
需要注意的是,我这里用到的AutoCompleteTextView的几个方法
1. setAdapter()方法:这里要传递的adapter参数必须是继承ListAdapter和Filterable的,其中arrayAdapter和simpleAdapter都能满足要求,我们常用arrayAdapter,因为他不需要像simpleAdapte那样设置他的显示位置和textview组件。
要想掌握它,就必须查看他的源码,我们可以看看arrayadapter是如何实现
凡是继承了Filterable的adapter都必须重写getFilter接口方法
public Filter getFilter() { if (mFilter == null) { mFilter = new ArrayFilter(); } return mFilter; }
这个filter 就是实现过滤方法的对象,同样,我们可以查看他的源码是如何实现的
/** * <p>An array filter constrains the content of the array adapter with * a prefix. Each item that does not start with the supplied prefix * is removed from the list.</p> */ private class ArrayFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence prefix) { FilterResults results = new FilterResults(); if (mOriginalValues == null) { synchronized (mLock) { mOriginalValues = new ArrayList<T>(mObjects); } } if (prefix == null || prefix.length() == 0) { synchronized (mLock) { ArrayList<T> list = new ArrayList<T>(mOriginalValues); results.values = list; results.count = list.size(); } } else { String prefixString = prefix.toString().toLowerCase(); final ArrayList<T> values = mOriginalValues; final int count = values.size(); final ArrayList<T> newValues = new ArrayList<T>(count); for (int i = 0; i < count; i++) { final T value = values.get(i); final String valueText = value.toString().toLowerCase(); // First match against the whole, non-splitted value if (valueText.startsWith(prefixString)) { newValues.add(value); } else { final String[] words = valueText.split(" "); final int wordCount = words.length; for (int k = 0; k < wordCount; k++) { if (words[k].startsWith(prefixString)) { newValues.add(value); break; } } } } results.values = newValues; results.count = newValues.size(); } return results; }
这是arrayAdapter自定义的一个私有内部类,所谓私有,就意味着你不能通过继承去修改这种过滤方法,同样你也不能直接得到他过滤后结果集results。假如你想使用新的过滤方法,你必须重写getfilter()方法,返回的filter对象是你要新建的filter对象(在里面包含performFiltering()方法重新构造你要的过滤方法)
2.setDropDownHeight方法 ,用来设置提示下拉框的高度,注意,这只是限制了提示下拉框的高度,提示数据集的个数并没有变化
3.setThreshold方法,设置从输入第几个字符起出现提示
4.setCompletionHint方法,设置提示框最下面显示的文字
5.setOnFocusChangeListener方法,里面包含OnFocusChangeListener监听器,设置焦点改变事件
6.showdropdown方法,让下拉框弹出来
我没有用到的一些方法列举
1.clearListSelection,去除selector样式,只是暂时的去除,当用户再输入时又重新出现
2.dismissDropDown,关闭下拉提示框
3.enoughToFilter,这是一个是否满足过滤条件的方法,sdk建议我们可以重写这个方法
4. getAdapter,得到一个可过滤的列表适配器
5.getDropDownAnchor,得到下拉框的锚计的view的id
6.getDropDownBackground,得到下拉框的背景色
7.setDropDownBackgroundDrawable,设置下拉框的背景色
8.setDropDownBackgroundResource,设置下拉框的背景资源
9.setDropDownVerticalOffset,设置下拉表垂直偏移量,即是list里包含的数据项数目
10.getDropDownVerticalOffset ,得到下拉表垂直偏移量
11..setDropDownHorizontalOffset,设置水平偏移量
12.setDropDownAnimationStyle,设置下拉框的弹出动画
13.getThreshold,得到过滤字符个数
14.setOnItemClickListener,设置下拉框点击事件
15.getListSelection,得到下拉框选中为位置
16.getOnItemClickListener。得到单项点击事件
17.getOnItemSelectedListener得到单项选中事件
18.getAdapter,得到那个设置的适配器
一些隐藏方法和构造我没有列举了,具体可以参考api文档
自定义:
网上找到的都是同ArrayAdapter一起使用的,有时候需要自定义风格,咋办?follow me!
看上图,实现了清空输入框内容和删除Item功能。
其实使用AutoCompleteTextView就得实现过滤器Filterable,你得告诉它怎么过滤。由于ArrayAdapter已经帮我们实现了Filterable接口,所以我们很容易忽略这个,以为AutoCompleteTextView用起来很简单。如果你使用的是BaseAdapter呢?当然,事实上也不难,只要让它也实现Filterable接口就可以了。
下面是源码:
实现自定义的Adapter
import java.util.ArrayList; import java.util.List; import qianlong.qlmobile.tablet.csco.R; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.View.OnClickListener; import android.widget.BaseAdapter; import android.widget.Filter; import android.widget.Filterable; import android.widget.ImageView; import android.widget.TextView; public class AutoCompleteAdapter extends BaseAdapter implements Filterable{ private Context context; private ArrayFilter mFilter; private ArrayList<String> mOriginalValues;//所有的Item private List<String> mObjects;//过滤后的item private final Object mLock = new Object(); private int maxMatch=10;//最多显示多少个选项,负数表示全部 public AutoCompleteAdapter(Context context,ArrayList<String> mOriginalValues,int maxMatch){ this.context=context; this.mOriginalValues=mOriginalValues; this.maxMatch=maxMatch; } @Override public Filter getFilter() { // TODO Auto-generated method stub if (mFilter == null) { mFilter = new ArrayFilter(); } return mFilter; } private class ArrayFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence prefix) { // TODO Auto-generated method stub FilterResults results = new FilterResults(); // if (mOriginalValues == null) { // synchronized (mLock) { // mOriginalValues = new ArrayList<String>(mObjects);// // } // } if (prefix == null || prefix.length() == 0) { synchronized (mLock) { Log.i("tag", "mOriginalValues.size="+mOriginalValues.size()); ArrayList<String> list = new ArrayList<String>(mOriginalValues); results.values = list; results.count = list.size(); return results; } } else { String prefixString = prefix.toString().toLowerCase(); final int count = mOriginalValues.size(); final ArrayList<String> newValues = new ArrayList<String>(count); for (int i = 0; i < count; i++) { final String value = mOriginalValues.get(i); final String valueText = value.toLowerCase(); // if(valueText.contains(prefixString)){//匹配所有 // // } // First match against the whole, non-splitted value if (valueText.startsWith(prefixString)) { //源码 ,匹配开头 newValues.add(value); } // else { // final String[] words = valueText.split(" ");//分隔符匹配,效率低 // final int wordCount = words.length; // // for (int k = 0; k < wordCount; k++) { // if (words[k].startsWith(prefixString)) { // newValues.add(value); // break; // } // } // } if(maxMatch>0){//有数量限制 if(newValues.size()>maxMatch-1){//不要太多 break; } } } results.values = newValues; results.count = newValues.size(); } return results; } @Override protected void publishResults(CharSequence constraint, FilterResults results) { // TODO Auto-generated method stub mObjects = (List<String>) results.values; if (results.count > 0) { notifyDataSetChanged(); } else { notifyDataSetInvalidated(); } } } @Override public int getCount() { // TODO Auto-generated method stub return mObjects.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub //此方法有误,尽量不要使用 return mObjects.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(final int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub ViewHolder holder = null; if(convertView==null){ holder=new ViewHolder(); LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); convertView=inflater.inflate(R.layout.simple_list_item_for_autocomplete, null); holder.tv=(TextView)convertView.findViewById(R.id.simple_item_0); holder.iv=(ImageView)convertView.findViewById(R.id.simple_item_1); convertView.setTag(holder); }else{ holder = (ViewHolder) convertView.getTag(); } holder.tv.setText(mObjects.get(position)); holder.iv.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String obj=mObjects.remove(position); mOriginalValues.remove(obj); notifyDataSetChanged(); } }); return convertView; } class ViewHolder { TextView tv; ImageView iv; } public ArrayList<String> getAllItems(){ return mOriginalValues; } }
import android.content.Context; import android.util.AttributeSet; import android.view.View; import android.widget.AutoCompleteTextView; import android.widget.ImageView; import android.widget.RelativeLayout; import android.widget.ImageView.ScaleType; public class AdvancedAutoCompleteTextView extends RelativeLayout{ private Context context; private AutoCompleteTextView tv; public AdvancedAutoCompleteTextView(Context context) { super(context); // TODO Auto-generated constructor stub this.context=context; } public AdvancedAutoCompleteTextView(Context context, AttributeSet attrs) { super(context, attrs); // TODO Auto-generated constructor stub this.context=context; } @Override protected void onFinishInflate() { super.onFinishInflate(); initViews(); } private void initViews() { RelativeLayout.LayoutParams params=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT); tv=new AutoCompleteTextView(context); tv.setLayoutParams(params); tv.setPadding(10, 0, 40, 0); // tv.setSingleLine(true); RelativeLayout.LayoutParams p=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT); p.addRule(RelativeLayout.ALIGN_PARENT_RIGHT); p.addRule(RelativeLayout.CENTER_VERTICAL); p.rightMargin=10; ImageView iv=new ImageView(context); iv.setLayoutParams(p); iv.setScaleType(ScaleType.FIT_CENTER); iv.setImageResource(R.drawable.delete); iv.setClickable(true); iv.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub tv.setText(""); } }); this.addView(tv); this.addView(iv); } public void setAdapter(AutoCompleteAdapter adapter){ tv.setAdapter(adapter); } public void setThreshold(int threshold){ tv.setThreshold(threshold); } public AutoCompleteTextView getAutoCompleteTextView(){ return tv; } }
simple_list_item_for_autocomplete.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:paddingTop="5dip" android:paddingBottom="5dip" > <TextView android:id="@+id/simple_item_0" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" android:paddingLeft="5dip" android:textColor="@android:color/black" /> <ImageView android:id="@+id/simple_item_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:scaleType="fitCenter" android:src="@drawable/delete" android:layout_centerVertical="true" android:layout_marginRight="5dip" /> </LinearLayout>
使用,通常情况下都这样:
private AdvancedAutoCompleteTextView tv; private AutoCompleteAdapter adapter; private ArrayList<String> mOriginalValues=new ArrayList<String>(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mOriginalValues.add("1234561"); mOriginalValues.add("1234562"); mOriginalValues.add("2234563"); mOriginalValues.add("2234564"); mOriginalValues.add("3234561111"); mOriginalValues.add("32345622222"); mOriginalValues.add("323456333333"); mOriginalValues.add("3234564444"); mOriginalValues.add("3234565555"); mOriginalValues.add("32345666666"); mOriginalValues.add("32345777777"); tv = (AdvancedAutoCompleteTextView) findViewById(R.id.tv); tv.setThreshold(0); adapter = new AutoCompleteAdapter(this, mOriginalValues, 10); tv.setAdapter(adapter); }
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