android内容提供者总结

35.内容提供者：ContentResolver
用内容提供者来获取联系人信息
35-1：权限
<!-- 对联系人的读、写权限 -->
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_CONTACTS" />
35-2：新建实体类存放联系人
int c_id;
String c_name;
String c_phone;
String c_email;
set和get方法以及构造方法
35-3：新建Uri
Uri uri = ContactsContract.Contacts.CONTENT_URI;//联系人姓名
Uri uriPhone = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;//联系人电话
Uri uriEmail = ContactsContract.CommonDataKinds.Email.CONTENT_URI;//联系人邮箱
35-4：新建ContentResolver
ContentResolver resolver = this.getContentResolver();
35-5：用邮标来获取联系人名字
35-5-1：新建地址，通过邮标查询
Cursor cursor = resolver.query(uri, null, null, null, null);
35-5-2：开始查询
int contactIdIndex = 0;//联系人ID
int nameIndex = 0;//联系人姓名
if(cursor.getCount()>0){
contactIdIndex = cursor.getColumnIndex(ContactsContract.Contacts._ID);
nameIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
}
35-5-3：通过邮标的moveToNext()方式获取值
while(cursor.moveToNext()){
String contactId = cursor.getString(contactIdIndex);
name = cursor.getString(nameIndex);
……（此处还有下文代码）
}
35-6：用邮标来获取联系人号码（在上文while循环的基础上继续）
35-6-1：新建电话号码的Cursor邮标
//selection相当于SQL中的Where语句吧
String selection = ContactsContract.CommonDataKinds.Phone.CONTACT_ID + "=" +contactId;
Cursor phones = this.getContentResolver().query(uriPhone,null, selection, null, null);
int phoneIndex = 0;
35-6-2如果查询到了，就返回phoneIndex
if(phones.getCount()>0){
phoneIndex = phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
}
35-6-3：同上获取值
while(phones.moveToNext()){
phoneNumber = phones.getString(phoneIndex);
……(如果还要获取邮箱，同理在此处写上代码)
}
35-7：获取邮箱
35-7-1：新建邮标查询
String selectionEmail = ContactsContract.CommonDataKinds.Email.CONTACT_ID +"="+contactId;
Cursor email = this.getContentResolver().query(uriEmail, null, selectionEmail, null, null);
35-7-2：查询并返回
int emailIndex = 0;
if(email.getCount()>0){
emailIndex = email.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA);
}
35-7-3：同上获取值
while (email.moveToNext()) {
Email = email.getString(emailIndex);
}

如果觉得看得麻烦，可以直接用下面现成的代码：
注：请加权限及实例

Toast.makeText(getApplicationContext(), "正在获取信息", 0).show();
ContentResolver resolver = this.getContentResolver();
Cursor cursor = resolver.query(uri, null, null, null, null);
int contactIdIndex = 0;
int nameIndex = 0;
Contact contact;
if (cursor.getCount() > 0) {
contactIdIndex = cursor.getColumnIndex(ContactsContract.Contacts._ID);
nameIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
}else{
Toast.makeText(getApplicationContext(), "您没有联系人信息", 0).show();
}
while (cursor.moveToNext()) {
String contactId = cursor.getString(contactIdIndex);
name = cursor.getString(nameIndex);

String selection = ContactsContract.CommonDataKinds.Phone.CONTACT_ID+ "=" + contactId;
Cursor phones = this.getContentResolver().query(uriPhone, null,selection, null, null);
int phoneIndex = 0;
if (phones.getCount() > 0) {
phoneIndex = phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
}
while (phones.moveToNext()) {
phoneNumber = phones.getString(phoneIndex);
Toast.makeText(getApplicationContext(), name+"==="+phoneNumber, 0).show();
contact = new Contact(name, phoneNumber);
list.add(contact);
}
}