安卓学习第二课——短信发送器

package com.example.message;

import android.app.Activity;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {
    private EditText et_number;
    private EditText et_message;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Button send=(Button) findViewById(R.id.send);
            et_number= (EditText) MainActivity.this.findViewById(R.id.et_number);
            et_message=(EditText) MainActivity.this.findViewById(R.id.et_message);
            send.setOnClickListener(this);
        }
        @Override
        public void onClick(View v) {
            switch(v.getId()){
            case R.id.send:
                sendmessage();
                break;
            }
        }
        private void sendmessage() {
            String number=et_number.getText().toString().trim();
            String message=et_message.getText().toString().trim();
            if(TextUtils.isEmpty(number)||TextUtils.isEmpty(message)){
                Toast.makeText(this, "电话号码或短信内容不能为空",Toast.LENGTH_SHORT).show();
                return;    
            }else{
                SmsManager smsManager =SmsManager.getDefault();
                smsManager.sendTextMessage(number, null, message, null, null);
                
            }
        
        }
}