android实现发短信

版权声明： https://blog.csdn.net/s0cket/article/details/78985976

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.big.yanzhuang.lsx.MainActivity">
    <EditText
        android:id="@+id/number"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="请输入手机号"
        android:inputType="number" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:gravity="center_vertical"
        android:orientation="horizontal" >

        <EditText
            android:id="@+id/msg_content"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:hint="请输入短信内容" />

        <Button
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:gravity="center_vertical"
            android:text="确认发送"
            android:textColor="#FF1493" />
    </LinearLayout>


</RelativeLayout>

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private EditText mNumberText;
    private EditText mContentText;

    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setTitle(getString(R.string.app_name));
        setContentView(R.layout.activity_main);

        mNumberText = (EditText) findViewById(R.id.number);
        mContentText = (EditText) findViewById(R.id.msg_content);
        findViewById(R.id.send).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {

        if(ContextCompat.checkSelfPermission(MainActivity.this,Manifest.permission.SEND_SMS) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.SEND_SMS}, 1);
        }
        else {
            sendMsg();
            
        }
        
    }

    private void sendMsg(){
        String content = mNumberText.getText().toString();
        String number = mContentText.getText().toString();
        try{
            if(TextUtils.isEmpty(number)){
                showToast("请输入手机号");
                return;
            }
            if(TextUtils.isEmpty(content)){
                showToast("请输入内容：");
                return;
            }
            ArrayList<String> messages = SmsManager.getDefault().divideMessage(content);
            for(String text:messages){
                SmsManager.getDefault().sendTextMessage(number,null,text,null,null);
            }
            showToast("Success!");
        } catch(SecurityException e){
            e.printStackTrace();
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode,String[] permissions,int[] grantResults) {
        switch(requestCode) {
            case 1:
                if(grantResults.length > 0 && grantResults[0]== PackageManager.PERMISSION_GRANTED){
                    sendMsg();
                } else {
                    Toast.makeText(this,"您没有此权限！",Toast.LENGTH_SHORT).show();
                }
                break;
            default:
        }
    }

    private void showToast(String msg){
        Toast.makeText(MainActivity.this,msg,Toast.LENGTH_SHORT).show();
    }
}

问题：有两处报错，主活动中的红色permisssion!!提示cannot resolve symbol