Intent intent=new Intent(this,Main2Activity.class);
startActivity(intent);<activity android:name=".Main2Activity">
<intent-filter>
<!-- 隐式intent传递的就是android.intent.action.start字符串 -->
<action android:name="android.intent.action.start" />
<!-- 注意设置成Default -->
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>Intent intent=new Intent("android.intent.action.start");
startActivity(intent);