package com.example.keyboardtest;

 import android.app.Activity;

 import android.os.Bundle;

 import android.view.KeyEvent;

 import android.view.View;

 import android.view.View.OnKeyListener;

 import android.widget.EditText;

 import android.widget.TextView;

 public class MainActivity extends Activity {

     private TextView text;

     private EditText edit;

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         //初始化值

         text=(TextView)findViewById(R.id.view);

         edit=(EditText)findViewById(R.id.edit);

         //设置键盘监听：

         edit.setOnKeyListener(new MyOnKeyListener());

     }

     //键盘的监听事件使用View.OnKeyListener()接口进行处理

     private class MyOnKeyListener implements OnKeyListener{

         @Override

         public boolean onKey(View arg0, int arg1, KeyEvent arg2) {

             //键盘按下与松开操作：

             switch (arg2.getAction()) {

             case KeyEvent.ACTION_UP:  //松开按键

                 String string=edit.getText().toString();

                 text.setText(str(string));

                 break;

             case KeyEvent.ACTION_DOWN: //键盘按下

                 break;

             default:

                 break;

             }

             return false;

         }

         //输入银行卡账号,用大字回显出来,每4个数字用“—”隔开

         private String str(String total) {

             String count="";

             for(int i=0;i<=total.length()/4;i++) {

                 //分段后最后不加“—”

                 if(i*4+4<total.length()) {

                     count=count+total.subSequence(i*4, Math.min(i*4+4,total.length()))+"-";

                 }else {

                     count=count+total.subSequence(i*4, Math.min(i*4+4, total.length()));

                 }

             }

             return count;

         }

     }

 }

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

     xmlns:tools="http://schemas.android.com/tools"

     android:layout_width="match_parent"

     android:layout_height="match_parent"

     android:orientation="vertical">

     <TextView

         android:id="@+id/theme"

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         android:text="手机号"/>

     <EditText

         android:id="@+id/edit"

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         android:ems="12"

         android:maxLength="12"/>

     <!-- android:ems属性表示将对应控件的宽度设为10个字符的宽度，设置该属性后，一行中最大只能显示该宽度的大小

         注意：当layout_width="match_parent"时，该属性不会生效

         android:maxLength属性表示最大可输入的字符数 -->

     <TextView

         android:id="@+id/view"

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         android:textSize="20sp"

         android:text=""/>

 </LinearLayout>

 <?xml version="1.0" encoding="utf-8"?>

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"

     package="com.example.keyboardtest"

     android:versionCode="1"

     android:versionName="1.0" >

     <uses-sdk

         android:minSdkVersion="18"

         android:targetSdkVersion="22" />

     <application

         android:allowBackup="true"

         android:icon="@drawable/ic_launcher"

         android:label="@string/app_name"

         android:theme="@style/AppTheme" >

         <activity

             android:name=".MainActivity"

             android:label="@string/app_name" >

             <intent-filter>

                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />

             </intent-filter>

         </activity>

     </application>

 </manifest>