Android的Activity之间的通信

Activity
</span>，叫做主<span lang="EN-US">Activity</span>，被启动的那个<span lang="EN-US">Activity</span>，叫做子<span lang="EN-US">Activity</span>。<span lang="EN-US"></span></span>

<p class="MsoNormal"><span style="font-family: mceinline;">主<span lang="EN-US">Activity </span>和子<span lang="EN-US">Acitivity
</span>之间进行通信的方法有很多种，下面介绍简单的方法。<span lang="EN-US"></span></span>

<p class="MsoNormal"><span style="font-family: mceinline;">通过<span lang="EN-US">Intent </span>来进行参数的传递。在<span lang="EN-US">Intent
</span>中有各种<span lang="EN-US">putXXX </span>方法来存放各种参数，然后在子<span lang="EN-US">Activity
</span>接收到这个<span lang="EN-US">Intent </span>时能够从这个<span lang="EN-US">Intent
</span>里取出这个参数，利用<span lang="EN-US">getIntnet()</span>、<span lang="EN-US">getXXXExtra()</span>方法就可以了。<span lang="EN-US"></span></span>

<span style="font-family: mceinline;">当一个主<span lang="EN-US">Activity
</span>想从一个子<span lang="EN-US">Activity
</span>接受消息时，可以使用<span lang="EN-US">StartActivityforResult </span>方法。例如，启动一个<span lang="EN-US">Activity</span>，<span lang="EN-US">startActivityForResult(intent, REQUEST_CODE); </span>然后在主<span lang="EN-US">Activity
</span>中的<span lang="EN-US">onActivityResult
</span>方法对<span lang="EN-US">requestCode
</span>进行判断，来对子<span lang="EN-US">Android
Activity </span>类不同的返回处理不同的情况。另外子<span lang="EN-US">Activity </span>也可以利用<span lang="EN-US">setResult </span>方法来设置主<span lang="EN-US">Activity </span>方法中的<span lang="EN-US">resultCode</span>，这样主<span lang="EN-US">Activity </span>也可以根据子<span lang="EN-US">Activity </span>的不同的<span lang="EN-US">resultCode </span>，来处理不同的情况。</span>