如何通过ContactsProvider获取联系人信息

要通过ContactsProvider获取联系人信息，您需要遵循以下步骤：

1. 首先，确保您的AndroidManifest.xml文件中包含读取联系人的权限。添加以下权限：

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

2. 在运行时请求权限（如果您的应用针对Android 6.0或更高版本）。在您的活动或片段中添加以下代码：

private static final int REQUEST_CODE = 1;

private void requestContactsPermission() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_CONTACTS}, REQUEST_CODE);
    } else {
        // Permission already granted, continue with your operation.
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    if (requestCode == REQUEST_CODE) {
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            // Permission granted, continue with your operation.
        } else {
            // Permission denied, inform the user.
        }
    }
}

3. 使用ContentResolver查询联系人数据。以下是一个示例方法，用于获取所有联系人的姓名和电话号码：

private void getContacts() {
    ContentResolver contentResolver = getContentResolver();
    Cursor cursor = contentResolver.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);

    if (cursor != null && cursor.moveToFirst()) {
        do {
            String contactId = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));
            String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));

            // Get phone numbers
            Cursor phoneCursor = contentResolver.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                    null, ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = ?", new String[]{contactId}, null);

            if (phoneCursor != null && phoneCursor.moveToFirst()) {
                do {
                    String phoneNumber = phoneCursor.getString(phoneCursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                    // Process the phone number, such as adding it to a list or displaying it in a TextView.
                } while (phoneCursor.moveToNext());
                phoneCursor.close();
            }

            // Get email addresses
            Cursor emailCursor = contentResolver.query(ContactsContract.CommonDataKinds.Email.CONTENT_URI,
                    null, ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = ?", new String[]{contactId}, null);

            if (emailCursor != null && emailCursor.moveToFirst()) {
                do {
                    String emailAddress = emailCursor.getString(emailCursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.ADDRESS));
                    // Process the email address, such as adding it to a list or displaying it in a TextView.
                } while (emailCursor.moveToNext());
                emailCursor.close();
            }

        } while (cursor.moveToNext());
        cursor.close();
    }
}

现在，您可以根据需要处理这些联系人信息，例如将其显示在列表视图中或将其发送到服务器。