=============== Problem description ====================
I want to run an APK to obtain the contact information of the mobile phone address book. The Code is as follows:
Mainactivity. Java:
Package com. example. getphonenumber;
Import Android. Support. v7.app. actionbaractivity;
Import Android. OS. Bundle;
Import Android. View. Menu;
Import Android. View. menuitem;
Public class mainactivity extends actionbaractivity {
@ Override
Protected void oncreate (bundle savedinstancestate ){
Super. oncreate (savedinstancestate );
Setcontentview (R. layout. activity_main );
}
@ Override
Public Boolean oncreateoptionsmenu (menu ){
// Inflate the menu; this adds items to the action bar if it is present.
Getmenuinflater (). Inflate (R. Menu. Main, menu );
Return true;
}
@ Override
Public Boolean onoptionsitemselected (menuitem item ){
// Handle action bar item clicks here. The action bar will
// Automatically handle clicks on the home/Up button, so long
// As you specify a parent activity in androidmanifest. xml.
Int id = item. getitemid ();
If (ID = R. Id. action_settings ){
Return true;
}
Return super. onoptionsitemselected (item );
}
}
Activity01.java:
Package com. example. getphonenumber;
Import Android. App. activity;
Import Android. content. contentresolver;
Import Android. database. cursor;
Import Android. OS. Bundle;
Import Android. provider. contactscontract;
Import Android. provider. contactscontract. phonelookup;
Import Android. widget. textview;
Public class activity01 extends activity {
Private int numberfieldcolumnindex;
Private string contact;
Public void oncreate (bundle savedinstancestate ){
Textview TV = new textview (this );
String string = "";
Super. oncreate (savedinstancestate );
Contentresolver Cr = getcontentresolver ();
Cursor cursor = Cr. Query (contactscontract. Contacts. content_uri, null );
While (cursor. movetonext ())
{Int namefieldcolumnindex = cursor. getcolumnindex (phonelookup. display_name );
String number = cursor. getstring (numberfieldcolumnindex );
String + = (contact + ":" + number + "\ n ");
}
Cursor. Close ();
TV. settext (string );
Setcontentview (TV );
}
}
Getphonenumber mainfest:
<? XML version = "1.0" encoding = "UTF-8"?>
<Manifest xmlns: Android = "http://schemas.android.com/apk/res/android"
Package = "com. example. getphonenumber"
Android: versioncode = "1"
Android: versionname = "1.0" type = "codeph" text = "/codeph">
<Uses-SDK
Android: minsdkversion = "8"
Android: targetsdkversion = "8"/>
<Uses-Permission
Android: Name = "android. Permission. read_contacts">
</Uses-Permission>
<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>
Activity_main.xml:
<Relativelayout 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: paddingbottom = "@ dimen/activity_vertical_margin"
Android: paddingleft = "@ dimen/activity_horizontal_margin"
Android: paddingright = "@ dimen/activity_horizontal_margin"
Android: paddingtop = "@ dimen/activity_vertical_margin"
Tools: context = "com. example. getphonenumber. mainactivity">
<Textview
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: text = "@ string/hello_world"/>
</Relativelayout>
But I only run Hello world.
============= Solution 1 ======================
<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>
Change mainactivity to your activity01.
============= Solution 2 ======================
...... In code format,
Code does not work
