一、选择图片：
使用插件 image_picker: “^0.5.0+3”
使用image_picker选择图片，代码如下：
// 相机拍照或者从图库选择图片pickImage(ctx) {// 如果已添加了1张图片，则提示不允许添加更多num size = fileList.length;if (size >= 1) {Scaffold.of(ctx).showSnackBar(new SnackBar(content: new Text("最多只能添加1张图片！"),));return;}showModalBottomSheet<void>(context: context, builder: _bottomSheetBuilder);}_renderBottomMenuItem(title, ImageSource source) {var item = new Container(height: 60.0,child: new Center(child: new Text(title)),);return new InkWell(child: item,onTap: () async {Navigator.of(context).pop();setState(() {_imageFile = ImagePicker.pickImage(source: source);});},);}Widget _bottomSheetBuilder(BuildContext context) {return new Container(height: 182.0,child: new Padding(padding: const EdgeInsets.fromLTRB(0.0, 30.0, 0.0, 30.0),child: new Column(children: <Widget>[_renderBottomMenuItem("相机拍照", ImageSource.camera),new Divider(height: 2.0,),_renderBottomMenuItem("图库选择照片", ImageSource.gallery)],),));}
选择图片后回调，代码如下
List<File> fileList = new List();Future<File> _imageFile;Widget build(BuildContext context) {return new Scaffold(body: new FutureBuilder(future: _imageFile,builder: (BuildContext context, AsyncSnapshot<File> snapshot) {if (snapshot.connectionState == ConnectionState.done && snapshot.data != null && _imageFile != null) {// 选择了图片（拍照或图库选择），添加到List中fileList.add(snapshot.data);// 阿里云OSS上传图片uploadImage(snapshot.data);_imageFile = null;}// 返回的widgetreturn listView();},),);}
二、上传图片
使用插件dio: “^2.0.0”
使用dio网络访问框架进行上传，代码如下
//上传图片uploadImage(File file) {//签名String url = Constants.BASE_URL + "/ossSignature";print("ossSignatureUrl: $url");NetUtils.get(url).then((obj) async {if (obj != null) {if (obj['code'] == 0) {var _sign = obj['data'];//创建dio对象Dio dio = new Dio();//dio的请求配置dio.options.responseType = ResponseType.plain;dio.options.contentType = ContentType.parse("multipart/form-data");//文件名String path = file.path;String chuo = DateTime.now().millisecondsSinceEpoch.toString() + path.substring(path.lastIndexOf('.'));String fileName = path.lastIndexOf('/') > -1 ? path.substring(path.lastIndexOf('/') + 1) : path;//创建一个FormData，作为dio的参数FormData formData = new FormData.from({'chunk': '0','OSSAccessKeyId': _sign['accessid'].toString(),'policy': _sign['policy'].toString(),'Signature': _sign['signature'].toString(),'Expires': _sign['expire'].toString(),'key': _sign['dir'] + chuo,'success_action_status': '200','Access-Control-Allow-Origin': '*','file': new UploadFileInfo(new File(path), fileName)});try {Response response = await dio.post(_sign['host'], data: formData);if (response.statusCode == 200) {setState(() {imgUrl = _sign['host'] + '/' + _sign['dir'] + chuo;});} else {Toast.show(context, '图片上传失败');}} on DioError catch (e) {Toast.show(context, '上传失败');print("get uploadImage error: $e");}}}}).catchError((e) {print("get uploadImage error: $e");});}
