参数类型 '_ProfileImageState' 不能分配给参数类型 'TickerProvider'

Question

主要目标是允许用户从图库/相机中选择图像，但为了使图像看起来更好，使用了一些动画并设计了整个图像选择对话框

class _ProfileImageState extends State<ProfileImage>{

      @override

      File _image;

      //ImagePickerHandler imagePicker;

      @override
      void initState() {

        super.initState();
//initiating to start so that transition from one state to another is smooth
 
        var _controller = new AnimationController(
          vsync: this,
          duration: const Duration(milliseconds: 500),
        );


        imagePicker=new ImagePickerHandler(this.userImage(_image));


      }

Answer 1

您需要使用 SingleTickerProviderStateMixin mixin 将其用作 vsyn c 参数。您可以通过使用 with 关键字来实现此目的

class _ProfileImageState extends State<ProfileImage> with SingleTickerProviderStateMixin {

      @override

      File _image;

      //ImagePickerHandler imagePicker;

      @override
      void initState() {

        super.initState();
 
        var _controller = new AnimationController(
          vsync: this,
          duration: const Duration(milliseconds: 500),
        );


        imagePicker=new ImagePickerHandler(this.userImage(_image));


      }```