ReactNative原生模块

1.原生模块

1.1Anroid

有三个NativeModule, JavaScriptModule, createViewManagers

2.IOS

应该有三个，导出模块或者原生View，都是用RCT_EXPORT_MODULE

2.Android原生View的显示bug

Android上，我发现一个View始终不显示，后来发现原因，是原生的View需要重绘，调用自己的requestLayout,再调用measureLayout

这个bug我找了好久，最后没办法试了一下，居然解决了。

private final Runnable mLayoutRunnable = new Runnable() {
    @Override
    public void run() {
      measure(
          MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
          MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
      layout(getLeft(), getTop(), getRight(), getBottom());
    }
  };

  @Override
  public void requestLayout() {
    super.requestLayout();

    // The toolbar relies on a measure + layout pass happening after it calls requestLayout().
    // Without this, certain calls (e.g. setLogo) only take effect after a second invalidation.
    post(mLayoutRunnable);
  }