package com.test.intentdemo;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
  private Button btn=null;
  public void onCreate(Bundle savedInstanceState)//onCreate方法用來初始化Activity實例對象
  {
    super.onCreate(savedInstanceState);//super.onCreate(savedInstanceState)的作用是調用其父類Activity的onCreate方法來實現(xiàn)對界面的圖畫繪制工作
    setContentView(R.layout.activity_main);//setContentView(R.layout.main)的作用是加載一個界面
    btn=(Button)findViewById(R.id.btn);
    btn.setOnClickListener(listener);
  }
  private View.OnClickListener listener=new View.OnClickListener()
  {
    @Override
    public void onClick(View v)
    {
//     Intent intent=new Intent();
//     intent.setAction(Intent.ACTION_SENDTO);
//     intent.setData(Uri.parse("smsto:5554"));
//     intent.putExtra("sms_body", "Hello!");//sms_body不能隨意換成
//     startActivity(intent);
      Intent intent=new Intent();
      intent.setClass(MainActivity.this, SecondActivity.class);//從一個activity跳轉到另一個activity
      intent.putExtra("str", "Intent Demo");//給intent添加額外數據，key為“str”,key值為"Intent Demo"
      startActivity(intent);
    }
  };
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
  }
}

package com.test.intentdemo;
import android.R.string;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class SecondActivity extends Activity
{
  private TextView secondTxt;
  @Override
  protected void onCreate(Bundle savedInstanceState)
  {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);
    Intent intent=getIntent();//getIntent將該項目中包含的原始intent檢索出來，將檢索出來的intent賦值給一個Intent類型的變量intent
    Bundle bundle=intent.getExtras();//.getExtras()得到intent所附帶的額外數據
    String str=bundle.getString("str");//getString()返回指定key的值
    secondTxt=(TextView)findViewById(R.id.secondTxt);//用TextView顯示值
    secondTxt.setText(str);
  }
}