​WXSDKInstance​是weex渲染页面的基本单元，

• 通过​instance.render(url)​拉取bundle，
• 在回调​IWXRenderListener​的​onViewCreated​返回创建的view，
• 将返回的view 添加到Activity的view上（rootView）

参见源码: WXPageActivity

public class MainActivity extends AppCompatActivity implements IWXRenderListener {
  WXSDKInstance mWXSDKInstance;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mWXSDKInstance = new WXSDKInstance(this);
    mWXSDKInstance.registerRenderListener(this);
    /**
    * bundleUrl source http://dotwe.org/vue/38e202c16bdfefbdb88a8754f975454c
    */
    String pageName = "WXSample";
    String bundleUrl = "http://dotwe.org/raw/dist/38e202c16bdfefbdb88a8754f975454c.bundle.wx";
    mWXSDKInstance.renderByUrl(pageName, bundleUrl, null, null,WXRenderStrategy.APPEND_ASYNC);
  }
  @Override
  public void onViewCreated(WXSDKInstance instance, View view) {
    setContentView(view);
  }
  @Override
  public void onRenderSuccess(WXSDKInstance instance, int width, int height) {
  }
  @Override
  public void onRefreshSuccess(WXSDKInstance instance, int width, int height) {
  }
  @Override
  public void onException(WXSDKInstance instance, String errCode, String msg) {
  }
  @Override
  protected void onResume() {
    super.onResume();
    if(mWXSDKInstance!=null){
      mWXSDKInstance.onActivityResume();
    }
  }
  @Override
  protected void onPause() {
    super.onPause();
    if(mWXSDKInstance!=null){
       mWXSDKInstance.onActivityPause();
    }
  }
  @Override
  protected void onStop() {
    super.onStop();
    if(mWXSDKInstance!=null){
      mWXSDKInstance.onActivityStop();
    }
  }
  @Override
  protected void onDestroy() {
    super.onDestroy();
    if(mWXSDKInstance!=null){
      mWXSDKInstance.onActivityDestroy();
    }
  }
}