1.创建程序

创建一个名为ReadSMS的应用程序，指定包名为package com.czt.readsms;设计用户交互界面，预览效果如图：

对应的的布局代码如下：

activity_main.xml

package com.czt.readsms;

import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private TextView tvSms;
    private TextView tvDes;
    private String text = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvSms = (TextView)findViewById(R.id.tv_sms);
        tvDes = (TextView)findViewById(R.id.tv_des);
        }
    //单击Button时触发的方法
    public void readSMS(View view){
        //查询系统的信息uri
        Uri uri = Uri.parse("content://sms/");
        //获取ContentResolver对象
        ContentResolver resolver = getContentResolver();
        //通过ContentResolver对象查询系统短息
      Cursor cursor = resolver.query(uri,new String[]{"_id","address","type","body","date"},null,null,null);
        List<SmsInfo> smsInfos = new ArrayList<SmsInfo>();
        if (cursor != null && cursor.getCount()>0){
            tvDes.setVisibility(View.VISIBLE);
            while (cursor.moveToNext()){
                int _id = cursor.getInt(0);
                String address = cursor.getString(1);
                int type = cursor.getInt(2);
                String body = cursor.getString(3);
                long date = cursor.getLong(4);
                SmsInfo smsInfo = new SmsInfo(_id,address,type,body,date);
                smsInfos.add(smsInfo);
            }
            cursor.close();
        }

        for (int i =0;i<smsInfos.size();i++){
            text +="手机号码："+smsInfos.get(i).getAddress()+"\n";
            text +="短信内容："+smsInfos.get(i).getBody()+"\n\n";
            tvSms.setText(text);
        }
    }
}

在上述代码中，设置了一个Button，定义了它的单击事件“readSMS”，单击按钮之后将查询到的短信信息显示到TextView中。

编写实体类

接下来创建一个实体类SmsInfo，用于封装短信的属性，存储单条短信的信息，它的成员变量为_id,dete,,type,body和address，具体代码如下：
Smsinfo.java

package com.czt.readsms;

public class SmsInfo {
    private int _id; //短信的主键
    private String address; //发送地址
    private int type; //类型
    private String body; //短信内容
    private long date; //时间
    public SmsInfo(int _id,String address,int type,String body,long date){
        this._id = _id;
        this.address = address;
        this.type = type;
        this.body = body;
        this.date = date;
    }

    public int get_id() {
        return _id;
    }

    public void set_id(int _id) {
        this._id = _id;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public long getDate() {
        return date;
    }

    public void setDate(long date) {
        this.date = date;
    }
}

3.编写界面交互代码
在MainActivity中编写交互代码，以实现查看系统短信的功能，具体代码如下：

package com.czt.readsms;

import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private TextView tvSms;
    private TextView tvDes;
    private String text = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvSms = (TextView)findViewById(R.id.tv_sms);
        tvDes = (TextView)findViewById(R.id.tv_des);
        }
    //单击Button时触发的方法
    public void readSMS(View view){
        //查询系统的信息uri
        Uri uri = Uri.parse("content://sms/");
        //获取ContentResolver对象
        ContentResolver resolver = getContentResolver();
        //通过ContentResolver对象查询系统短息
      Cursor cursor = resolver.query(uri,new String[]{"_id","address","type","body","date"},null,null,null);
        List<SmsInfo> smsInfos = new ArrayList<SmsInfo>();
        if (cursor != null && cursor.getCount()>0){
            tvDes.setVisibility(View.VISIBLE);
            while (cursor.moveToNext()){
                int _id = cursor.getInt(0);
                String address = cursor.getString(1);
                int type = cursor.getInt(2);
                String body = cursor.getString(3);
                long date = cursor.getLong(4);
                SmsInfo smsInfo = new SmsInfo(_id,address,type,body,date);
                smsInfos.add(smsInfo);
            }
            cursor.close();
        }

        for (int i =0;i<smsInfos.size();i++){
            text +="手机号码："+smsInfos.get(i).getAddress()+"\n";
            text +="短信内容："+smsInfos.get(i).getBody()+"\n\n";
            tvSms.setText(text);
        }
    }
}

在上述代码中，实现了利用ContentResolver读取系统短信功能，单击Button按钮将读取到的短信显示到主页面上。需要注意的是，在使用完Cursor之后，一定要关闭，否则会造成内存泄漏。

4.添加权限

该案例进行了读取短信的操作，因此需要在AndroidMainfest。xml文件中加上读取的短信的权限，代码如下：

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