android 通过WIFI实现文件传输

package pip.Wifi;

import wyf.wpf.R;
import wyf.wpf.choosecontactlocal;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class WifiStart extends Activity {

 private static final int OPEN = 1;
 private static final int SERVEROPEN = 2;
 private static final int MODIFYOPEN = 3;
 private WifiManager mWifiManager;
 private WifiInfo mWifiInfo;
 private TextView usernametext = null;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.wifistart); // 设置当前屏幕

  mWifiManager = (WifiManager) this
    .getSystemService(Context.WIFI_SERVICE);

  mWifiInfo = mWifiManager.getConnectionInfo();
  String ip = intToIp(mWifiInfo.getIpAddress());

  usernametext = (TextView) findViewById(R.id.username);
  usernametext.setText(Build.MODEL);

  Toast.makeText(WifiStart.this, ip, Toast.LENGTH_SHORT).show();

 }

 /************** 点击了“发送Wifi文件” ***************/
 public void StartButton(View view) {

  if (mWifiManager.getWifiState() != WifiManager.WIFI_STATE_ENABLED) {
   showDialog(OPEN);// 调用onCreateDialog
  } else {
   Intent i = new Intent(WifiStart.this, WifiUserList.class);
   // Intent i = new Intent(WifiStart.this, choosecontactlocal.class);
   i.putExtra("username", usernametext.getText().toString());
   startActivity(i);
  }
 }

 /************** 点击了“接收Wifi文件” ***************/
 public void ReceiveButton(View view) {

  if (mWifiManager.getWifiState() != WifiManager.WIFI_STATE_ENABLED) {
   showDialog(SERVEROPEN);// 调用onCreateDialog
  } else {
   Intent intent = new Intent(WifiStart.this, WifiReceive.class);
   intent.putExtra("username", usernametext.getText().toString());
   startActivity(intent);
  }

 }

 /************** 点击了“修改您的用户名” ***************/
 public void ModifyButton(View view) {

  showDialog(MODIFYOPEN);// 调用onCreateDialog
 }

 /************** 提示是否打开Wifi提示框 ***************/
 protected Dialog onCreateDialog(int id) {
  switch (id) {
  case OPEN:
   return new AlertDialog.Builder(WifiStart.this).setTitle("温馨提示")
     .setMessage("您的WiFi处于关闭状态，是否打开？").setIcon(
       android.R.drawable.ic_dialog_info)
     .setPositiveButton("打开", new OnClickListener() {

      public void onClick(DialogInterface dialog, int which) {

       mWifiManager.setWifiEnabled(true);
       Toast.makeText(WifiStart.this, "已为您启动WiFi服务",
         Toast.LENGTH_SHORT).show();

       Intent i = new Intent(WifiStart.this,
         WifiUserList.class);
       startActivity(i);

      }
     }).setNegativeButton("取消", new OnClickListener() {

      public void onClick(DialogInterface dialog, int which) {

       Toast.makeText(WifiStart.this, "您的WiFi服务未启动",
         Toast.LENGTH_SHORT).show();

      }
     }).create();
  case SERVEROPEN:
   return new AlertDialog.Builder(WifiStart.this).setTitle("温馨提示")
     .setMessage("您的WiFi处于关闭状态，是否打开？").setIcon(
       android.R.drawable.ic_dialog_info)
     .setPositiveButton("打开", new OnClickListener() {

      public void onClick(DialogInterface dialog, int which) {

       mWifiManager.setWifiEnabled(true);
       Toast.makeText(WifiStart.this, "已为您启动WiFi服务",
         Toast.LENGTH_SHORT).show();

       Intent i = new Intent(WifiStart.this,
         WifiReceive.class);
       startActivity(i);

      }
     }).setNegativeButton("取消", new OnClickListener() {

      public void onClick(DialogInterface dialog, int which) {

       Toast.makeText(WifiStart.this, "您的WiFi服务未启动",
         Toast.LENGTH_SHORT).show();

      }
     }).create();
  case MODIFYOPEN:
   // 新建一个编辑框，默认显示设备名称 "_"
   final EditText deviceTypeEdit = new EditText(this);
   deviceTypeEdit.setText(Build.MODEL);
   // 把光标定位到最后一个字符后面
   deviceTypeEdit.setSelection(Build.MODEL.length());
   // 弹出对话框要求用户输入设备型号或标识
   new AlertDialog.Builder(this).setTitle("请输入设备型号或标识：").setView(
     deviceTypeEdit).setPositiveButton("确定",
     new DialogInterface.OnClickListener() {

      public void onClick(DialogInterface dialog, int which) {
       // 获取用户输入后的设备类型
       String devicetype = deviceTypeEdit.getText()
         .toString().trim();
       usernametext.setText(devicetype);

      }
     }).setNegativeButton("取消", null).show();
  default:
   return null;
  }
 }

 private String intToIp(int i) {

  return (i & 0xFF) "." ((i >> 8) & 0xFF) "." ((i >> 16) & 0xFF)
     "." ((i >> 24) & 0xFF);

 }

 @Override
 public void onBackPressed() {
  // TODO Auto-generated method stub
  super.onBackPressed();
 }

 @Override
 protected void onStop() {
  // TODO Auto-generated method stub
  super.onStop();

 }

}