求大神帮忙运行一下，分析一下原因，我后面把书里的源码也拉来试了一下，还是报空指针。感觉似乎是Cursor的原因，求大神指点！谢谢！！
package com.example.marcus.groupsend;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.provider.ContactsContract;
import android.support.v7.app.AlertDialog;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity extends Activity {
Button select,send;
EditText numbers,content;
SmsManager smsManager;
ArrayList<String> phoneNumbers = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
numbers = (EditText) findViewById(R.id.numbers);
content = (EditText) findViewById(R.id.content);
smsManager = SmsManager.getDefault();
send = (Button) findViewById(R.id.send);
select = (Button) findViewById(R.id.select);
//发送信息
send.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
PendingIntent pi = PendingIntent.getActivity(MainActivity.this,0,new Intent(),0);
for (String number : phoneNumbers){
smsManager.sendTextMessage(number,null,content.getText().toString(),pi,null);
}
Toast.makeText(MainActivity.this,"群发成功!",Toast.LENGTH_SHORT).show();
}
});
//选择群发号码,采用复选框方式
select.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//获取到系统联系人
final Cursor cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
null,
null,
null,
null);
BaseAdapter adapter = new BaseAdapter() {
@Override
public int getCount() {
return cursor.getCount();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
cursor.moveToPosition(position);
//使用复选框
CheckBox checkBox = new CheckBox(MainActivity.this);
//获取当前位置选中的号码,并去掉空格和-,然后加入到checkBox中
String number = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER))
.replace("-","")
.replace(" ","");
checkBox.setText(number);
if (isChecked(number)){
checkBox.setChecked(true);
}
//返还一个复选框视图
return checkBox;
}
};
View selectView = getLayoutInflater().inflate(R.layout.list,null);
final ListView list = (ListView) selectView.findViewById(R.id.list);
list.setAdapter(adapter);
//利用对话框来加载View,View中是一个复选框列表
new AlertDialog.Builder(MainActivity.this).setView(selectView).
setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//先将phoneNumbers里面清空
phoneNumbers.clear();
//遍历list里面的各个条目,如果是打勾的就加到这个phoneNumbers列表里
for (int i=0; i<list.getCount(); i++){
CheckBox check = (CheckBox)list.getChildAt(i);
if (check.isChecked()){
phoneNumbers.add(check.getText().toString());
}
}
//最终全部加到这个列表中,并在send里遍历各个号码,然后实现群发功能
numbers.setText(phoneNumbers.toString());
}
}).show();
}
});
}
//判断某个号码是否在群发范围内
public boolean isChecked(String number) {
for (String s : phoneNumbers){
if (s.equals(number)){
return true;
}
}
return false;
}
}
以下是我的两个xml文件
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/numbers"
android:layout_weight="8"
android:layout_width="0dp"
android:layout_height="wrap_content" />
<Button
android:id="@+id/select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="select"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:id="@+id/content"
android:layout_weight="8"
android:layout_width="0dp"
android:layout_height="wrap_content" />
<Button
android:id="@+id/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="send"/>
</LinearLayout>
</LinearLayout>
list.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
