Enable a new activity to obtain its return value. The activity gets the return value.

Enable a new activity to obtain its return value. The activity gets the return value.

1. Start Interface

<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" tools: context = ". mainActivity "> <LinearLayout android: layout_width =" fill_parent "android: layout_height =" wrap_content "android: orientation =" horizontal "> <EditText android: id = "@ + id/et_number" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: hint = "enter a contact"/> <Button android: onClick = "click" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "Contact"/> </LinearLayout> <LinearLayout android: layout_width = "fill_parent" android: layout_height = "wrap_content" android: orientation = "horizontal"> <EditText android: id = "@ + id/et_number2" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: hint = "enter a contact"/> <Button android: onClick = "click2" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "Contact 2"/> </LinearLayout>

2. enable the new activity code.

1 package com. example. smssender; 2 3 import android. OS. bundle; 4 import android. app. activity; 5 import android. content. intent; 6 import android. view. menu; 7 import android. view. view; 8 import android. widget. editText; 9 10 public class MainActivity extends Activity {11 12 private EditText et_number; 13 private EditText et_number2; 14 @ Override15 protected void onCreate (Bundle savedInstanceState) {16 s Uper. onCreate (savedInstanceState); 17 setContentView (R. layout. activity_main); 18 et_number = (EditText) findViewById (R. id. et_number); 19 et_number2 = (EditText) findViewById (R. id. et_number2); 20} 21 22 public void click (View view) {23 Intent intent = new Intent (this, ContactActivity. class); 24 // startActivity (intent); 25 // The request code is used to identify who initiated the request 26 startActivityForResult (intent, 1 ); 27} 28 29 public void click2 (View view) {30 Intent intent = new Intent (this, ContactActivity. class); 31 // startActivity (intent); 32 // The request code is used to identify who initiated the request 33 startActivityForResult (intent, 2 ); 34} 35 36 37 @ Override38 protected void onActivityResult (int requestCode, int resultCode, Intent data) {39 // TODO Auto-generated method stub40 super. onActivityResult (requestCode, resultCode, data); 41 if (data! = Null) {42 String number = data. getStringExtra ("number"); 43 if (requestCode = 1) {44 et_number.setText (number); 45} else {46 et_number2.setText (number ); 47} 48} 49} 50 51}

3. Get contacts

1) inventory file

<Uses-permission android: name = "android. permission. READ_CONTACTS"/> // permission

2) Get a contact through the content provider

1 package com. example. smssender; 2 3 import java. util. arrayList; 4 import java. util. list; 5 6 import android. content. contentResolver; 7 import android. content. context; 8 import android. database. cursor; 9 import android.net. uri; 10 11 public class ContactService {12 public static List <contactInfo> getContactAll (Context context) {13 List <contactInfo> infos = new ArrayList <contactInfo> (); 14 // get the contact through the content provider Contact 15 ContentResolver resolver = context. getContentResolver (); 16 Uri uri = Uri. parse ("content: // com. android. contacts/raw_contacts "); 17 Uri dataUri = Uri. parse ("content: // com. android. contacts/data "); 18 Cursor cursor = resolver. query (uri, null, null); 19 while (cursor. moveToNext () {20 String id = cursor. getString (cursor. getColumnIndex ("contact_id"); 21 Cursor datacursor = resolver. query (dat AUri, null, "raw_contact_id =? ", New String [] {id}, null); 22 contactInfo info = new contactInfo (); 23 while (datacursor. moveToNext () {24 String data1 = datacursor. getString (datacursor. getColumnIndex ("data1"); 25 String mimetype = datacursor. getString (datacursor. getColumnIndex ("mimetype"); 26 if ("vnd. android. cursor. item/name ". equals (mimetype) {27 info. setUsername (data1); 28} else if ("vnd. android. cursor. item/phone_v2 ". equals (mimetype) {29 info. setNumber (data1); 30} 31} 32 33 infos. add (info); 34 35} 36 return infos; 37} 38}

4. Set the contact to go to Listview

 1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     android:orientation="vertical" > 6      7     <ListView 8         android:layout_width="match_parent" 9         android:layout_height="match_parent" 10         android:id="@+id/lv_contact"11         ></ListView>12 13 </LinearLayout>

 1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     android:orientation="vertical" > 6      7     <TextView  8         android:id="@+id/et_username" 9         android:layout_width="match_parent"10         android:layout_height="wrap_content"11         />12     <TextView 13         android:id="@+id/et_number"14         android:layout_width="match_parent"15         android:layout_height="wrap_content"16         />17 18 </LinearLayout>

Java code:

1 package com. example. smssender; 2 3 import java. util. list; 4 5 import android. app. activity; 6 import android. content. contentResolver; 7 import android. content. intent; 8 import android. database. cursor; 9 import android.net. uri; 10 import android. OS. bundle; 11 import android. view. view; 12 import android. view. viewGroup; 13 import android. widget. adapterView; 14 import android. widget. adapterView. onItemClick Listener; 15 import android. widget. baseAdapter; 16 import android. widget. listView; 17 import android. widget. textView; 18 19 public class ContactActivity extends Activity {20 21 private ListView lv_contact; 22 private List <contactInfo> infos = null; 23 @ Override24 protected void onCreate (Bundle savedInstanceState) {25 26 // TODO Auto-generated method stub27 super. onCreate (savedInstanceState); 28 setConten TView (R. layout. activity_contact); 29 30 infos = ContactService. getContactAll (this); 31 32 lv_contact = (ListView) findViewById (R. id. lv_contact); 33 lv_contact.setAdapter (new ContactAdapter (); 34 35 lv_contact.setOnItemClickListener (new OnItemClickListener () {36 37 @ Override38 public void onItemClick (AdapterView <?> Arg0, View arg1, int arg2, 39 long arg3) {40 // TODO Auto-generated method stub41 contactInfo info = infos. get (arg2); 42 String number = info. getNumber (); 43 Intent data = new Intent (); 44 data. putExtra ("number", number); 45 setResult (0, data); 46 // close the current activity and send the data back to its activator 47 finish (); 48 49} 50 51}); 52} 53 54 private class ContactAdapter extends BaseAdapter {55 56 @ Override57 public int getCount () {58 // TODO Auto-generated method stub59 return infos. size (); 60} 61 62 @ Override63 public Object getItem (int arg0) {64 // TODO Auto-generated method stub65 return null; 66} 67 68 @ Override69 public long getItemId (int arg0) {70 // TODO Auto-generated method stub71 return 0; 72} 73 74 @ Override75 public View getView (int arg0, view arg1, ViewGroup arg2) {76 // TODO Auto-generated method stub77 contactInfo info = infos. get (arg0); 78 View view = View. inflate (ContactActivity. this, R. layout. contact_item, null); 79 TextView et_username = (TextView) view. findViewById (R. id. et_username); 80 et_username.setText (info. getUsername (); 81 82 TextView et_number = (TextView) view. findViewById (R. id. et_number); 83 et_number.setText (info. getNumber (); 84 85 return view; 86} 87 88} 89 90}