从联系人电子邮件检索联系人姓名时获取null值

Question

我想从联系人电子邮件中检索联系人姓名，所以我所做的如下https://stackoverflow.com/a/18064869/5738881.

 public static String readContacts(Context context, String email) {
    ContentResolver cr = context.getContentResolver();
    Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
    Cursor cursor = cr.query(uri, new String[]{ContactsContract.PhoneLookup.DISPLAY_NAME}, null, null, null);
    if (cursor == null) {
        return null;
    }
    String contactName = null;
    if (cursor.moveToFirst()) {
        contactName = cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
    }
    if (!cursor.isClosed()) {
        cursor.close();
    }
    Log.e("....contact name....", email + "n" + contactName);
    return contactName;
}

然后在onCreate（）中，我编码为，

 sName = readContacts(getApplicationContext(), sEmail);
    etName.setText(sName);

但我得到的是null值。因此，根据联系人的电子邮件地址，获取联系人姓名的方法是什么？

第1版：

我已经在清单中提到了许可，

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

第2版：

根据ROHIT SHARMA的回答，我将代码更改如下。

 public static String readContacts(Context context, String email) {
    ContentResolver cr = context.getContentResolver();
    Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
    Cursor cursor = cr.query(uri, new String[]{ContactsContract.PhoneLookup.DISPLAY_NAME}, null, null, null);
    if (cursor == null) {
        return null;
    }
    String contactName = null;
    if (cursor.getCount() > 0) {
        cursor.moveToFirst();
    } else {
        return null;
    }
    if (cursor.moveToFirst()) {
        contactName = cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
    }
    if (!cursor.isClosed()) {
        cursor.close();
    }
    Log.e("....contact name....", email + "n" + contactName);
    return contactName;
}

但这对我没有帮助。

第3版：

public static String readContacts(Context context, String email) {
ContentResolver cr = context.getContentResolver();
Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
Cursor cursor = cr.query(uri, new String[]{ContactsContract.PhoneLookup.DISPLAY_NAME}, null, null, null);
String contactName = null;
if(cursor!=null && cursor.getCount()>0 )
{ 
 cursor.moveToFirst();
 contactName =  cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
}else{ 
   return null; 
} 
if (!cursor.isClosed()) {
    cursor.close();
} 
Log.e("....contact name....", email + "n" + contactName);
return contactName;
}

这对我也没有帮助。

第4版：

我试过

 public String readContacts(Context context, String email) {
    String name = null;
    // define the columns I want the query to return
    String[] projection = new String[]{
            ContactsContract.PhoneLookup.DISPLAY_NAME,
            ContactsContract.PhoneLookup._ID};
    // encode the email and build the filter URI
    Uri contactUri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
    // query time
    Cursor cursor = context.getContentResolver().query(contactUri, projection, null, null, null);
    if (cursor != null) {
        if (cursor.moveToFirst()) {
            name = cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
            Log.e("....email.....", "Started uploadcontactphoto: Contact Found @ " + email);
            Log.e("....name....", "Started uploadcontactphoto: Contact name  = " + name);
        } else {
            Log.e("....email exception....", "Contact Not Found @ " + email);
        }
        cursor.close();
    }
    return name;
}

来自https://stackoverflow.com/a/15007980/5738881但也无济于事。

有没有其他出路？

第5版：

public String readContacts() {
    ContentResolver cr = getContentResolver();
    @SuppressLint("Recycle")
    Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI,
            null, null, null, null);
    String id, name = null, email = null;
    if (cur != null && cur.getCount() > 0) {
        while (cur.moveToNext()) {
            id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
            name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
            if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                System.out.println("name : " + name + ", ID : " + id);
                // get the phone number
                Cursor pCur = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,
                        ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = ?",
                        new String[]{id}, null);
                if (pCur != null) {
                    while (pCur.moveToNext()) {
                        String phone = pCur.getString(
                                pCur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                        System.out.println("phone" + phone);
                    }
                }
                if (pCur != null) {
                    pCur.close();
                }

                // get email and type
                Cursor emailCur = cr.query(
                        ContactsContract.CommonDataKinds.Email.CONTENT_URI,
                        null,
                        ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = ?",
                        new String[]{id}, null);
                if (emailCur != null) {
                    while (emailCur.moveToNext()) {
                        // This would allow you get several email addresses
                        // if the email addresses were stored in an array
                        email = emailCur.getString(
                                emailCur.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));
                        String emailType = emailCur.getString(
                                emailCur.getColumnIndex(ContactsContract.CommonDataKinds.Email.TYPE));

                        System.out.println("Email " + email + " Email Type : " + emailType);
                    }
                    if (email == sEmail) {
                        sName = name;
                    }
                }
                if (emailCur != null) {
                    emailCur.close();
                }
            }
        }
    }
    return name;
}

我从中尝试了以上代码实例http://www.coderzheaven.com/2011/06/13/get-all-details-from-contacts-in-android/我得到了名字，但它和电子邮件id所有者的名字不同。

那么，告诉我哪里出了问题。。

从上面的代码片段来看，我也尝试过

if (email == sEmail) {
                            sName = name;
                        }
                        System.out.println("Email " + email + " Email Type : " + emailType);
                    }

                }
                if (emailCur != null) {
                    emailCur.close();
                }

而不是

                        System.out.println("Email " + email + " Email Type : " + emailType);
                    }
                    if (email == sEmail) {
                        sName = name;
                    }
                }
                if (emailCur != null) {
                    emailCur.close();
                }

但也无济于事。

Answer 1

您应该更换

 Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
Cursor cursor = cr.query(uri, new String[]{ContactsContract.PhoneLookup.DISPLAY_NAME}, null, null, null);

带有

Uri uri = Uri.withAppendedPath(ContactsContract.CommonDataKinds.Email.CONTENT_FILTER_URI, Uri.encode(email));
    Cursor cursor = cr.query(uri, new String[]{ContactsContract.CommonDataKinds.Email.CONTACT_ID,
            ContactsContract.Data.DISPLAY_NAME}, null, null, null);

然后测试它。

Answer 2

使用getCount之前，请始终检查它。

if(cursor!=null && cursor.getCount()>0 )
{
 cursor.moveToFirst();

}else{
   return null;
}

还要检查您是否已声明允许读取清单中的联系人：

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

您还需要一些其他相关权限，请查看文档中的内容以了解哪些权限。

我建议尝试这种方式，并使用断点调试代码问题出在哪里。

public static String readContacts(Context context, String email) {
    ContentResolver cr = context.getContentResolver();
    Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI, Uri.encode(email));
    Cursor cursor = cr.query(uri, new String[]{ContactsContract.PhoneLookup.DISPLAY_NAME}, null, null, null);
    String contactName = null;
    if(cursor!=null && cursor.getCount()>0 )
    {
     cursor.moveToFirst();
     contactName =  cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
    }else{
       return null;
    }
    if (!cursor.isClosed()) {
        cursor.close();
    }
    Log.e("....contact name....", email + "n" + contactName);
    return contactName;
}