GetBuilder

StatefullWidget

1、StatefullWidget

void initState() {
    // _GetBuilderState._currentState = this;
    super.initState();
    widget.initState?.call(this);

    var isRegistered = GetInstance().isRegistered<T>(tag: widget.tag); //获取GetxController

    if (widget.global) {
      if (isRegistered) {
        if (GetInstance().isPrepared<T>(tag: widget.tag)) {
          _isCreator = true;
        } else {
          _isCreator = false;
        }
        controller = GetInstance().find<T>(tag: widget.tag); //获取GetxController
      } else {
        controller = widget.init;
        _isCreator = true;
        GetInstance().put<T>(controller!, tag: widget.tag);//获取GetxController
      }
    } else {
      controller = widget.init; //创建GetxController
      _isCreator = true;
      controller?.onStart();
    }

    if (widget.filter != null) {
      _filter = widget.filter!(controller!);
    }

    _subscribeToController(); // 进入第2步
  }

2、 GetxController 绑定

  void _subscribeToController() {
    _remove?.call();
    _remove = (widget.id == null)
        ? controller?.addListener( //添加update
            _filter != null ? _filterUpdate : getUpdate,
          )
        : controller?.addListenerId(
            widget.id,
            _filter != null ? _filterUpdate : getUpdate,
          );
  }


// update，调用setState 刷新界面
 void getUpdate() {
    if (mounted) setState(() {});
  }


//GetXcontroller 添加update

  Disposer addListener(GetStateUpdate listener) {
    assert(_debugAssertNotDisposed());
    _updaters!.add(listener); // 添加update
    return () => _updaters!.remove(listener);
  }

3、 GetXcontroller 调用 update 刷新statefullWidget

//在logic 中调用update 
  void update([List<Object>? ids, bool condition = true]) {
    if (!condition) {
      return;
    }
    if (ids == null) {
      refresh(); //继续下一步
    } else {
      for (final id in ids) {
        refreshGroup(id);
      }
    }
  }

  void refresh() {
    assert(_debugAssertNotDisposed());

    /// This debounce the call to update.
    /// It prevent errors and duplicates builds
    // if (_microtask == _version) {
    //   _microtask++;
    //   scheduleMicrotask(() {
    //     _version++;
    //     _microtask = _version;
    _notifyUpdate(); //继续下一步
    // });
    // }
  }


 void _notifyUpdate() { //到这里刷新
    for (var element in _updaters!) { //看到这个 _updaters 了没，对应就是 StateufullWidget的getUpdate 方法
      element!();
    }
  }