本文主要是介绍一步一步学android控件（之六） —— MultiAutoCompleteTextView，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
今天学习的控件是MultiAutoCompleteTextView 。 提到MultiAutoCompleteTextView 我们就自然而然地想到AutoCompleteTextView ，就想知道他们之间到底有什么区别。在讲他们区别之前呢先来看看下面两张图片：
（图1）AutoCompleteTextView （图2）MultiAutoCompleteTextView
这两张图片中使用的都是同样的Adapter ， 然而在图1中输入图2中的内容时却得不到任何内容，为什么？
先从他们的关系上说说， MultiAutoCompleteTextView 继承自AutoCompleteTextView（废话 ... 囧） ， 在使用上多了一个Tokenizer —— 在图2中，这个Tokenizer就是符号 ‘ , ’ ，当遇到这个符号时会根据光标的位置计算当前关注的信息。如：如果光标在 d 的位置，则 ‘ , ’之前的字串有效；如果光标在 g 位置，则 ‘ , ’ 后面的字串有效；另外如果光标前后都有符号‘ , ’ ， 则在两个 ‘ , ’ 中的内容有效。对于这段解释，下面的代码获取更具说服力：
public static class SelfDedineTokenizer implements Tokenizer {private char mTokenizer = ',';public SelfDedineTokenizer() {}public SelfDedineTokenizer(char token) {mTokenizer = token;}public int findTokenEnd(CharSequence text, int cursor) {int i = cursor;int len = text.length();while (i < len) {if (text.charAt(i) == mTokenizer) {return i;} else {i++;}}return len;}public int findTokenStart(CharSequence text, int cursor) {int i = cursor;while (i > 0 && text.charAt(i - 1) != mTokenizer) {i--;}while (i < cursor && text.charAt(i) == ' ') {i++;}return i;}public CharSequence terminateToken(CharSequence text) {int i = text.length();while (i > 0 && text.charAt(i - 1) == ' ') {i--;}if (i > 0 && text.charAt(i - 1) == mTokenizer) {return text;} else {if (text instanceof Spanned) {SpannableString sp = new SpannableString(text+ String.valueOf(mTokenizer));TextUtils.copySpansFrom((Spanned) text, 0, text.length(),Object.class, sp, 0);return sp;} else {return text + String.valueOf(mTokenizer);}}}public void setToken(char token) {mTokenizer = token;}public char getToken() {return mTokenizer;}}
废话也说了那么多了，现在说说今天要做的事情
1、使用异步调用方法（Executors）加载MultiAutoCompleteTextView 中 Adapter 需要的数据（数据跟AutoCompleteTextView一样，有疑问的可参见 点击一步一步学android控件（之五） —— AutoCompleteTextView）
2、在MultiAutoCompleteTextView中使用自定义的Tokenizer而不是默认的Tokenizer。
下面就来实现这些功能，老规矩先准备资源文件
1、 创建布局文件 multi_auto_complete_textview.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" ><MultiAutoCompleteTextViewandroid:id="@+id/show_multi_complete"android:layout_width="match_parent"android:layout_height="wrap_content"android:padding="10dp"android:layout_marginTop="20dp" /></LinearLayout>package com.xy.zt.selfdefinewieget;import java.io.File;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.TextUtils;
import android.widget.ArrayAdapter;
import android.widget.MultiAutoCompleteTextView;
import android.widget.MultiAutoCompleteTextView.Tokenizer;public class WidgetMultiAutoCompleteActivity extends Activity {public static final String[] DEFAULT_DATAS = new String[] { "China","chengdu", "xueyu", "ting", "baba", "mama", "meimei" };public static final int MSG_RECEIVE_TASK_DATA = 1024;private ExecutorService mExecutor;private ArrayAdapter<String> mMultiAdapter;private MultiAutoCompleteTextView mShowMulti;// private CommaTokenizer mComma = new CommaTokenizer();private Future<List<String>> mListFileTask;private static final Callable<List<String>> LIST_FILES = new Callable<List<String>>() {public List<String> call() throws Exception {File rootDir = Environment.getRootDirectory();LinkedList<File> queue = new LinkedList<File>();ArrayList<String> result = new ArrayList<String>(100);queue.offer(rootDir);File tmpFile, tmpDirAllFile[];while ((tmpFile = queue.poll()) != null) {if (tmpFile.isDirectory()) {tmpDirAllFile = tmpFile.listFiles();if (tmpDirAllFile != null) {for (File f : tmpDirAllFile) {queue.offer(f);}}} else {result.add(tmpFile.getName());}}return result;}};Handler mHandler = new Handler() {@SuppressWarnings("unchecked")@Overridepublic void handleMessage(Message msg) {switch (msg.what) {case MSG_RECEIVE_TASK_DATA:List<String> datas;try {datas = (List<String>) msg.obj;} catch (ClassCastException e) {datas = useDefaultData();}mShowMulti.setEnabled(true);mMultiAdapter = new ArrayAdapter<String>(WidgetMultiAutoCompleteActivity.this,R.layout.auto_complete_item, R.id.auto_item_file_name,datas);mShowMulti.setAdapter(mMultiAdapter);break;};}};@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.multi_auto_complete_textview);init();mExecutor = Executors.newCachedThreadPool();mListFileTask = mExecutor.submit(LIST_FILES);mExecutor.submit(new Runnable() {@SuppressLint("HandlerLeak")public void run() {List<String> datas;try {datas = mListFileTask.get();} catch (InterruptedException e) {datas = useDefaultData();} catch (ExecutionException e) {datas = useDefaultData();}Message msg = mHandler.obtainMessage(MSG_RECEIVE_TASK_DATA);msg.obj = datas;mHandler.sendMessage(msg);}});}void init() {mShowMulti = (MultiAutoCompleteTextView) findViewById(R.id.show_multi_complete);mShowMulti.setEnabled(false);mShowMulti.setTokenizer(mCustomerToken);mShowMulti.setThreshold(1);}private List<String> useDefaultData() {List<String> datas = new ArrayList<String>();for (String s : DEFAULT_DATAS) {datas.add(s);}return datas;}@Overrideprotected void onDestroy() {super.onDestroy();mExecutor.shutdown();}SelfDedineTokenizer mCustomerToken = new SelfDedineTokenizer(';');public static class SelfDedineTokenizer implements Tokenizer {private char mTokenizer = ',';public SelfDedineTokenizer() {}public SelfDedineTokenizer(char token) {mTokenizer = token;}public int findTokenEnd(CharSequence text, int cursor) {int i = cursor;int len = text.length();while (i < len) {if (text.charAt(i) == mTokenizer) {return i;} else {i++;}}return len;}public int findTokenStart(CharSequence text, int cursor) {int i = cursor;while (i > 0 && text.charAt(i - 1) != mTokenizer) {i--;}while (i < cursor && text.charAt(i) == ' ') {i++;}return i;}public CharSequence terminateToken(CharSequence text) {int i = text.length();while (i > 0 && text.charAt(i - 1) == ' ') {i--;}if (i > 0 && text.charAt(i - 1) == mTokenizer) {return text;} else {if (text instanceof Spanned) {SpannableString sp = new SpannableString(text+ String.valueOf(mTokenizer));TextUtils.copySpansFrom((Spanned) text, 0, text.length(),Object.class, sp, 0);return sp;} else {return text + String.valueOf(mTokenizer);}}}public void setToken(char token) {mTokenizer = token;}public char getToken() {return mTokenizer;}}
}
private static final Callable<List<String>> LIST_FILES = new Callable<List<String>>()mExecutor = Executors.newCachedThreadPool();mListFileTask = mExecutor.submit(LIST_FILES);mExecutor.submit(new Runnable() {@SuppressLint("HandlerLeak")public void run() {List<String> datas;try {datas = mListFileTask.get();} catch (InterruptedException e) {datas = useDefaultData();} catch (ExecutionException e) {datas = useDefaultData();}Message msg = mHandler.obtainMessage(MSG_RECEIVE_TASK_DATA);msg.obj = datas;mHandler.sendMessage(msg);}});
在init函数中有这么一句：
mShowMulti.setTokenizer(mCustomerToken);SelfDedineTokenizer mCustomerToken = new SelfDedineTokenizer(';');
3、 完善真个工程，下面滴内容也是不可少滴。也写了几个控件了，看看现在ViewData.java中的内容
package com.xy.zt.selfdefinewieget.data;import java.util.ArrayList;final public class ViewData {public final static ArrayList<ViewData> View_Datas = new ArrayList<ViewData>();public static final int TEXT_VIEW_ID = 90000;public static final String TEXT_VIEW_NAME = "TextView";public static final int BUTTON_ID = TEXT_VIEW_ID + 1;public static final String BUTTON_NAME = "Button";public static final int EDIT_TEXT_ID = BUTTON_ID + 1;public static final String EDIT_TEXT_NAME = "EditText";public static final int AUTO_COMPLETE_TEXTVIEW_ID = EDIT_TEXT_ID + 1;public static final String AUTO_COMPLETE_TEXTVIEW_NAME = "AutoCompleteTextView";public static final int MULTI_AUTO_COMPLETE_TEXTVIEW_ID = AUTO_COMPLETE_TEXTVIEW_ID + 1;public static final String MULTI_AUTO_COMPLETE_TEXTVIEW_NAME = "MultiAutoCompleteTextView";private static final ViewData mTextView = new ViewData(TEXT_VIEW_NAME,TEXT_VIEW_ID);private static final ViewData mButton = new ViewData(BUTTON_NAME, BUTTON_ID);private static final ViewData mEditText = new ViewData(EDIT_TEXT_NAME,EDIT_TEXT_ID);private static final ViewData mAutoCompleteTextView = new ViewData(AUTO_COMPLETE_TEXTVIEW_NAME, AUTO_COMPLETE_TEXTVIEW_ID);private static final ViewData mMultiAutoCompleteTextView = new ViewData(MULTI_AUTO_COMPLETE_TEXTVIEW_NAME, MULTI_AUTO_COMPLETE_TEXTVIEW_ID);public final String mViewName;public final int mViewId;private ViewData(String name, int id) {mViewName = name;mViewId = id;}static {View_Datas.add(mTextView);View_Datas.add(mButton);View_Datas.add(mEditText);View_Datas.add(mAutoCompleteTextView);View_Datas.add(mMultiAutoCompleteTextView);}
}
最后在WidgetsAdapter的handleItemClicked函数中加入如下内容：
case ViewData.MULTI_AUTO_COMPLETE_TEXTVIEW_ID:intent.setClass(mContext, WidgetMultiAutoCompleteActivity.class);mContext.startActivity(intent);break;private void handleItemClicked(int action) {Intent intent = new Intent();switch (action) {case ViewData.TEXT_VIEW_ID:intent.setClass(mContext, WidgetTextView.class);mContext.startActivity(intent);break;case ViewData.BUTTON_ID:intent.setClass(mContext, WidgetButtonActivity.class);mContext.startActivity(intent);break;case ViewData.EDIT_TEXT_ID:intent.setClass(mContext, WidgetEditTextActivity.class);mContext.startActivity(intent);break;case ViewData.AUTO_COMPLETE_TEXTVIEW_ID:intent.setClass(mContext, WidgetAutoCompleteActivity.class);mContext.startActivity(intent);break;case ViewData.MULTI_AUTO_COMPLETE_TEXTVIEW_ID:intent.setClass(mContext, WidgetMultiAutoCompleteActivity.class);mContext.startActivity(intent);break;}}MultiAutoCompleteTextView 就介绍到这里了，下一个控件 Toast 。
这篇关于一步一步学android控件（之六） —— MultiAutoCompleteTextView的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
