我试图将一个数组中的联系人名称和他们的类型放在另一个数组中,但是无法通过空指针异常来完成.这是我的代码.我已经指出了我得到空指针异常的行.请帮忙..提前致谢.
package application.test;
import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.database.SQLException;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.Contacts.Data;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.RelativeLayout;
public final class TestActivity extends Activity {
String[] name;
String[] phoneType;
ListView lv;
ListViewAdapter lva;
public static final String TAG = "ContactManager";
@Override
public void onCreate(Bundle savedInstanceState)
{
Log.v(TAG, "Activity State: onCreate()");
super.onCreate(savedInstanceState);
LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
LinearLayout mainLayout=new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LayoutInflater layoutInflater = getLayoutInflater();
mainLayout.addView(layoutInflater.inflate(R.layout.main,null));
mainLayout.addView(layoutInflater.inflate(R.layout.extra,null));
this.addContentView(mainLayout, params);
lv = (ListView)findViewById(android.R.id.list);
lva = new ListViewAdapter(this,name,phoneType);
lv.setAdapter(lva);
testGetContacts();
}
private void testGetContacts() {
ContentResolver cr = getContentResolver();
String[] projection = new String[] { Data._ID,
ContactsContract.Contacts.DISPLAY_NAME, Phone.TYPE};
Cursor cur = cr.query(ContactsContract.Data.CONTENT_URI,
projection, null, null, null);
if (cur != null && cur.moveToFirst()) {
try {
int indexID = cur.getColumnIndexOrThrow(ContactsContract.Contacts._ID);
int indexName = cur.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME);
int indexPhoneType = cur.getColumnIndexOrThrow(Phone.TYPE);
while (cur.moveToNext()) {
int i=1;
String id = cur.getString(indexID);
//HERE LIES NULL POINTER EXCEPTION name[i] = cur.getString(indexName);
//HERE TOO phoneType[i] = cur.getString(indexPhoneType);
i++;
System.out.println(id + "\n");
System.out.println(name + "\n");
System.out.println(phoneType + "\n");
}
} catch (SQLException sqle) {
//handling exception
} finally {
if (!cur.isClosed()) {
cur.close();
}
}
}
}
}
解决方法:
在使用之前初始化String []名称.
你可以这样做:
name=new String[cur.getCount()];
String s="";
while (cur.moveToNext()) {
int i=1;
String id = cur.getString(indexID);
name[i] = cur.getString(indexName);
phoneType[i] = cur.getString(indexPhoneType);
//System.out.println(id + "\n");
//System.out.println(name + "\n");
//System.out.println(phoneType + "\n");
s=s+"id="+id+" name="+name[i]+" phoneType="+phoneType[i]+"\n";
i++;
}
Toast.makeText(getApplicationContext(),i+" - "+s).show();
编辑:
在布局文件夹中创建一个xml文件.
main.xml中
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:orientation="vertical" >
<ListView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/listview"
android:cacheColorHint="#0000"
/>
</LinearLayout>
现在在你的TestActivity.class中:
public final class TestActivity extends Activity {
String[] name;
String[] phoneType;
ListView lv;
String s[];
public static final String TAG = "ContactManager";
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.id.main);
testGetContacts();
lv = (ListView)findViewById(R.id.listview);
ArrayAdapter<String> sa=new ArrayAdapter<String>(context, android.R.layout.simple_list_item_1,s);
lv.setAdapter(sa);
}
private void testGetContacts() {
ContentResolver cr = getContentResolver();
String[] projection = new String[] { Data._ID,
ContactsContract.Contacts.DISPLAY_NAME, Phone.TYPE};
Cursor cur = cr.query(ContactsContract.Data.CONTENT_URI,
projection, null, null, null);
if (cur != null && cur.moveToFirst()) {
try {
int indexID = cur.getColumnIndexOrThrow(ContactsContract.Contacts._ID);
int indexName = cur.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME);
int indexPhoneType = cur.getColumnIndexOrThrow(Phone.TYPE);
name=new String[cur.getCount()];
s=new String[cur.getCount()];
while (cur.moveToNext()) {
int i=1;
String id = cur.getString(indexID);
name[i-1] = cur.getString(indexName);
phoneType[i-1] = cur.getString(indexPhoneType);
String temp="id="+id+"-name="+name[i-1]+"-phoneType="+phoneType[i-1];
s[i-1]=temp;
i++;
}
}