通过ContentProvider访问手机设备中联系人的信息,并通过ListView展示出来。
一、设计main_activity.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.think.contentprovidertest.MainActivity">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/list_view"
/>
</LinearLayout>
二、设计ListView子项布局item_layout.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/text_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="15sp"
/>
<TextView
android:id="@+id/text_phnumber"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="15sp"
/>
</LinearLayout>
三、编写储存联系人信息的Data类:
package com.example.think.contentprovidertest;
/**
* Created by Think on 2018/3/23.
*/
public class Data {
String name;
String phnumber;
public Data(String name,String phnumber) {
this.name=name;
this.phnumber=phnumber;
}
public String getName() {
return name;
}
public String getPhnumber() {
return phnumber;
}
}
四、定义ArrayAdapter子类(为ListView配置适配器做准备):
package com.example.think.contentprovidertest;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.List;
/**
* Created by Think on 2018/3/23.
*/
public class MyAdapter extends ArrayAdapter<Data> {
int mresource;
public MyAdapter(@NonNull Context context, int resource, @NonNull List<Data> objects) {
super(context, resource, objects);
mresource=resource;
}
@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
Data data=getItem(position);
View view;
ViewHolder holder;
if(convertView==null) {
view= LayoutInflater.from(getContext()).inflate(mresource,parent,false);
holder=new ViewHolder(view);
view.setTag(holder);
} else {
view=convertView;
holder=(ViewHolder)view.getTag();
}
holder.textView1.setText(data.getName());
holder.textView2.setText(data.getPhnumber());
return view;
}
class ViewHolder {
TextView textView1;
TextView textView2;
public ViewHolder(View view) {
textView1=(TextView)view.findViewById(R.id.text_name);
textView2=(TextView)view.findViewById(R.id.text_phnumber);
}
}
}
五、MianActivity:
package com.example.think.contentprovidertest;
import android.database.Cursor;
import android.provider.ContactsContract;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
MyAdapter adapter;
ListView listView;
List<Data> dataList=new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView=(ListView)findViewById(R.id.list_view);
adapter=new MyAdapter(MainActivity.this,R.layout.item_layout,dataList);
listView.setAdapter(adapter);
initDatas();
}
public void initDatas() {
Cursor cursor=getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,null,null,null);
if(cursor!=null) {
while(cursor.moveToNext()) {
String name=cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
String phnumber=cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
Data data=new Data(name,phnumber);
dataList.add(data);
}
cursor.close();
}
adapter.notifyDataSetChanged();
}
}
总结:这个程序虽然简单,但它能够很好的展示了对已有ContentProvider的使用,以及对ListView的使用,它的设计步骤主要如下:
1、编写Adapter的子类,并为ListView绑定适配器
2、编写存储联系人信息的Data类
3、使用ContentResolver接口访问手机设备的联系人信息
4、调用ContentResolver类中的query方法获取联系人信息,并将信息添加到Data类型的链表dataList中
5、通过调用adapter对象的notifyDataSetChanged()方法将dataList中的数据更新到ListView中进行展现