我在安卓的短信功能工作，我可以通过短信发送用户的位置和地址，作为我的应用程序的要求，数量有限的联系人，现在我想实现进度对话框，所以当用户点击发送按钮的进度对话框应该出现，发送短信后，所有联系人的进度对话框应该消失。
我为此搜索了很多，但它使我非常困惑如何为我的应用程序，因为我是一个初学者在android！
有谁能帮助我在我的类中实现onpreexecute（）、onpostexecute（）和doinbackground（）方法吗？这里我要介绍我的发送短信的java类。

package com.example.ghaznavi.myapp;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.telephony.SmsManager;
import android.util.Log;
import android.widget.Toast;
import android.content.IntentFilter;

public class SmsHandler{

    Settings setObj=new Settings();
    double latitude,longitude;

    public SmsHandler() {
    }

    public void SendSms(final Context hcontext)
    {
        GPSService mGPSService = new GPSService(hcontext);
        LocationAddress locObj=new LocationAddress();
        mGPSService.getLocation();

        latitude = mGPSService.getLatitude();
        longitude = mGPSService.getLongitude();

        StringBuilder sb = new StringBuilder(160);
        String addd=  locObj.getAddressFromLocation(latitude,longitude,hcontext);

        sb.append("Hi, I m in trouble, Please Help!\n\n");

        if ((latitude != 0.0) && (longitude!= 0.0)) {
            sb.append("Map Link:").append("\n").append("https://maps.google.com/maps?q=").append(latitude).append("%2C").append(longitude).append("\n\n");
        }

        if (addd != null) {
            sb.append("Address: ").append(addd).append("\n\n");
        }
        sb.append( "- My Application");

        setObj.Initialize(hcontext);

        if (setObj.GetContactListCount()!=0)
        {

        for(int i=0;i<setObj.GetContactListCount();i++)
        {
            try
            {
                String SENT = "SMS_SENT";
                PendingIntent sentPI = PendingIntent.getBroadcast(hcontext, 0, new Intent(
                        SENT), 0);
                BroadcastReceiver sendSMS = new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context arg0, Intent arg1) {
                        switch (getResultCode()) {
                            case Activity.RESULT_OK:
                                Toast.makeText(hcontext, "SMS sent Successfully",
                                        Toast.LENGTH_SHORT).show();
                                break;
                            case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                                Toast.makeText(hcontext, "Generic failure",
                                        Toast.LENGTH_SHORT).show();
                                break;
                            case SmsManager.RESULT_ERROR_NO_SERVICE:
                                Toast.makeText(hcontext, "No service",
                                        Toast.LENGTH_SHORT).show();
                                break;
                            case SmsManager.RESULT_ERROR_NULL_PDU:
                                Toast.makeText(hcontext, "Null PDU",
                                        Toast.LENGTH_SHORT).show();
                                break;
                            case SmsManager.RESULT_ERROR_RADIO_OFF:
                                Toast.makeText(hcontext, "Radio off",
                                        Toast.LENGTH_SHORT).show();
                                break;
                        }
                    }
                };

               SmsManager localSmsManager = SmsManager.getDefault();
                if (sb.toString().length() <= 160) {
                    hcontext.registerReceiver(sendSMS, new IntentFilter(SENT));
                    localSmsManager.sendTextMessage(setObj.GetContactListNumber()[i], null, sb.toString(), sentPI, null);
                } else {
                    hcontext.registerReceiver(sendSMS, new IntentFilter(SENT));
                   localSmsManager.sendTextMessage(setObj.GetContactListNumber()[i], null, sb.toString().substring(0, 159),sentPI, null);
                    localSmsManager.sendTextMessage(setObj.GetContactListNumber()[i], null, sb.toString().substring(160),sentPI, null);
                }

                }
            catch (SecurityException localSecurityException)
            {
                Log.e("Error", "Security Exception, SMS permission denied");
                return;
            }
            }
            }
        else
        {
            Toast.makeText(hcontext,"please select a number",Toast.LENGTH_SHORT).show();
        }
    }
}

如有任何帮助，将不胜感激，提前谢谢！