Android 在listview中填充电话联系人时出错

我试图在自定义列表视图中填充我的联系人列表 但是我面临这个问题

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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<ListView
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:id="@+id/listView"
    android:layout_centerHorizontal="true"
    android:layout_alignParentBottom="true" />

扩展CursorAdapter的适配器类

类适配器扩展了游标适配器{

    Context context;
    Cursor c;

    public Adapter(Context context , Cursor c ) {
        super(context, c, 0);
        this.context = context;
        this.c = c;
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
        View v = getLayoutInflater().inflate(R.layout.listview_item, viewGroup, false);

        return v;
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {


            TextView name = (TextView) findViewById(R.id.name);
            name.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)));
            TextView num = (TextView) findViewById(R.id.num);
            num.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER)));

        }
    }
}

这里是LogCat异常

03-26 20:56:55.450    1847-1847/com.examples.anabil.contentproviderex E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
        at com.examples.anabil.contentproviderex.MainActivity$Adapter.bindView(MainActivity.java:79)
        at android.widget.CursorAdapter.getView(CursorAdapter.java:250)
        at android.widget.AbsListView.obtainView(AbsListView.java:2177)
        at android.widget.ListView.measureHeightOfChildren(ListView.java:1247)
        at android.widget.ListView.onMeasure(ListView.java:1159)
        at android.view.View.measure(View.java:15848)
        at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
        at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
        at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:453)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189)
        at android.view.View.measure(View.java:15848)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
        at android.view.Choreographer.doCallbacks(Choreographer.java:562)
        at android.view.Choreographer.doFrame(Choreographer.java:532)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
        at android.os.Handler.handleCallback(Handler.java:730)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5103)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)

---

VadymVL应答将修复您的空指针错误

访问原始联系人表（ContactsContact.Contacts）速度较慢。请尝试使用ContactsContact.CommonDataTypes.Phone：

public Uri uri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
String [] cols = {ContactsContract.CommonDataKinds.Phone.CONTACT_ID
         , ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME
         , ContactsContract.CommonDataKinds.Phone.NUMBER}; 

String selections =  ContactsContract.CommonDataKinds.Phone.HAS_PHONE_NUMBER + " = '1'";

Cursor Cursor = contentResolver.query(uri, cols, selections, null, null);

在bindView中：

@Override
public void bindView(View view, Context context, Cursor cursor) {

        TextView name = (TextView) view.findViewById(R.id.name);
        name.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME)));
        TextView num = (TextView) view.findViewById(R.id.num);
        num.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
    }
}

---

您是否在XML中声明了id为

name

和

num

的TextView项？此外，请尝试在

bindView（）

方法中进行更改：

TextView name=（TextView）view.findViewById（R.id.name）；

很抱歉，我忘记复制XML代码，但我最近没有尝试在

bindView（）

方法中进行更改：

TextView name=（TextView）view.findViewById（R.id.name）；

（第二个TextView也是如此）？是的！它可以工作，但为什么它只给num TextView中的数字1，因为您正在查询它：

getContentResolver（）.query（uri，cols，selections，新字符串[]{“1”}，null）

谢谢，但是Contacts类和CommonDataTypes类之间有什么不同？Contacts-具有原始的联系人详细信息，不包含电话号码、电子邮件、昵称等数据。您需要查询Contacts Contacts。这些详细信息的数据。使用CommonDataTypes.phone或CommandataTypes.email等数据更简单您需要的特定数据。

public Uri uri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
String [] cols = {ContactsContract.CommonDataKinds.Phone.CONTACT_ID
         , ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME
         , ContactsContract.CommonDataKinds.Phone.NUMBER}; 

String selections =  ContactsContract.CommonDataKinds.Phone.HAS_PHONE_NUMBER + " = '1'";

Cursor Cursor = contentResolver.query(uri, cols, selections, null, null);

@Override
public void bindView(View view, Context context, Cursor cursor) {

        TextView name = (TextView) view.findViewById(R.id.name);
        name.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME)));
        TextView num = (TextView) view.findViewById(R.id.num);
        num.setText(cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)));
    }
}