<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/phonenumber_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/phonenumber" />

    <EditText
        android:id="@+id/phonenumber_edit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/phonenumber_text"
        android:inputType="phone" >
    </EditText>

    <TextView
        android:id="@+id/phonenumber_text2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/phonenumber_edit"
        android:text="@string/phonenumber" />

    <EditText
        android:id="@+id/message_edit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/phonenumber_text2"
        android:lines="5" />

    <Button
        android:id="@+id/call_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@id/message_edit"
        android:onClick="callphone"
        android:text="call" />

</RelativeLayout>

import android.annotation.SuppressLint;
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;

import java.util.ArrayList;

public class SendMessage extends Activity implements OnClickListener {

    private EditText phonenumber_edit;
    private EditText content_eidt;
    private Button Send_button;
    private String content ;
    private  String phoneNumber;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
    }
    /**
     * 
     * @Title: initViews 
     * @Description: TODO(初始化布局文件) 
     * @param     设定文件 
     * @return void    返回类型 
     * @throws
     */
    private void initViews() {
        phonenumber_edit = (EditText)findViewById(R.id.phonenumber_edit);
        content_eidt = (EditText)findViewById(R.id.message_edit);
        Send_button = (Button)findViewById(R.id.call_button);
        Send_button.setOnClickListener(this);
    }
    /**
     * 
     * @Name onClick
     * @Description TODO(按钮单击事件处理) 
     * @param v
     * @see android.view.View.OnClickListener#onClick(android.view.View)
     * @Date 2013-12-8 下午10:28:30
     *
     */
    @SuppressLint("NewApi")
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            //打你发送短信按钮
            case R.id.call_button:
                //取得短信内容
                content = content_eidt.getText().toString().trim();
                //取得手机号码
                phoneNumber = phonenumber_edit.getText().toString().trim();
                //判断字符是否为空
                if(TextUtils.isEmpty(content)||TextUtils.isEmpty(phoneNumber)){
                    Toast.makeText(getApplicationContext(), "请输入内容", Toast.LENGTH_LONG).show();
                    return;
                }
                //短信发送
                SmsManager smsManager = SmsManager.getDefault();
                ArrayList<String> contents = smsManager.divideMessage(content);
                for (String string : contents) {
                    smsManager.sendTextMessage(phoneNumber, null, string, null, null);
                }
                Toast.makeText(getApplicationContext(), "短信已经发送", Toast.LENGTH_LONG).show();
                break;

            default:
                break;
        }

    }
}

   <!-- 发送短信权限的权限 -->
    <uses-permission android:name="android.permission.SEND_SMS" />