【问题标题】:In Flutter How to get image path after selecting images using Multi Image Picker?在 Flutter 中使用 Multi Image Picker 选择图像后如何获取图像路径?
【发布时间】:2020-06-26 17:03:57
【问题描述】:

我想从选定的多个图像中获取一个图像路径,我正在使用这个link 来选择多个图像,但我有资产,我想要来自选定的多个图像的路径,因为我想上传到 API。 我在pubspec.yaml添加了这个依赖如果有什么好的方法请告诉我

multi_image_picker: ^4.6.3

这是我的文件上传类,这个 UI 看起来很像 Facebook。

import 'dart:typed_data';
import 'package:auto_size_text/auto_size_text.dart';
import 'package:flutter/material.dart';
import 'package:multi_image_picker/multi_image_picker.dart';

class UpdateStatus extends StatefulWidget {
  @override
  _UpdateStatusState createState() => _UpdateStatusState();
}

class _UpdateStatusState extends State<UpdateStatus> {
  List<Asset> images = List<Asset>();
  String _error = 'No Error Dectected';

  Future<ByteData> byteData;
 // List<int> imageData = byteData.buffer.asUint8List();

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Create Post'),
        actions: <Widget>[
          Padding(
            padding: const EdgeInsets.all(18.0),
            child: InkWell(child: Text('POST',style: TextStyle(fontSize: 18.0),),onTap: ()
              {
                print('Post this post');
              },),
          )
        ],
      ),
      body: SingleChildScrollView(
        child: Container(
          height: MediaQuery.of(context).size.height,
          width:MediaQuery.of(context).size.width ,
          color: Colors.white,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: <Widget>[
              Container(
                height: 300.0,
                color: Colors.white,
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: TextFormField(
                    keyboardType: TextInputType.multiline,
                    maxLines: 100,
                      style: new TextStyle(
                          fontSize: 18.0,
                          color: Colors.black
                      ),
                    decoration: InputDecoration(
                      hintText: 'Enter your Post Details Here !',
                      border: InputBorder.none,
                    ),
                  ),
                ),
              ),
              Divider(
                thickness: 1.0,
              ),
              Column(
                children: <Widget>[
                  Container(
                    height: 40.0,
                    color: Colors.white70,
                    child: Padding(
                      padding:EdgeInsets.only(left: 18.0,),
                      child: InkWell(
                        child: Row(
                          children: <Widget>[
                            Icon(Icons.add_a_photo,),
                            Text("  Choose Image",style: TextStyle(fontSize: 24.0,),),
                          ],
                        ),
                        onTap: ()
                        {
                          print(images.toList().toString());
                          print('choose image from local');
                        },
                      ),
                    ),
                  ),
                  Divider(
                    thickness: 1.0,
                  ),
                  Container(
                    height: 40.0,
                    color: Colors.white70,
                    child: Padding(
                      padding:EdgeInsets.only(left: 18.0,),
                      child: InkWell(
                        child: Row(
                          children: <Widget>[
                            Icon(Icons.add_photo_alternate,),
                            Text("  Choose Video",style: TextStyle(fontSize: 24.0,),),
                          ],
                        ),
                        onTap: ()
                        {
                          print('choose video from local');
                        },
                      ),
                    ),
                  ),
                ],
              ),
              Divider(
                thickness: 1.0,
              ),
         Container(
           height: 200,
              child: Column(
                children: <Widget>[
                  Center(child: Text('Error: $_error')),
                  RaisedButton(
                    child: Text("Pick images"),
                    onPressed: loadAssets,
                  ),
                  Expanded(
                    child: buildGridView(),
                  )
                ],
              ),
         ),
         /*
          Column(
            children: <Widget>[
              Center(child: Text('Error: $_error')),
              RaisedButton(
                child: Text("Pick images"),
                onPressed: loadAssets,
              ),
              Expanded(
                child: buildGridView(),
              )
            ],
          ),

              */
            ],
          ),
        ),
      ),
    );
  }

  Future<void> loadAssets() async {

    List<Asset> resultList = List<Asset>();
    String error = 'No Error Dectected';

    ByteData byteData;


    try {
      resultList = await MultiImagePicker.pickImages(
        maxImages: 300,
        enableCamera: true,
        selectedAssets: images,
        cupertinoOptions: CupertinoOptions(takePhotoIcon: "chat"),
        materialOptions: MaterialOptions(
          actionBarColor: "#abcdef",
          actionBarTitle: "Ilma",
          allViewTitle: "All Photos",
          useDetailsView: false,
          selectCircleStrokeColor: "#000000",
        ),
      );

    } on Exception catch (e) {
      error = e.toString();
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      images = resultList;
      _error = error;
      print('000000000000000000000');
      print('000000000000000000000');
      print(images);
      print('000000000000000000000');
      print('000000000000000000000');
    });



  }

  Widget buildGridView() {
    return GridView.count(
      crossAxisCount: 3,
      children: List.generate(images.length, (index) {
        Asset asset = images[index];

        byteData=asset.getByteData();

        print('0000');
        print(byteData);
        print('0000');



        return AssetThumb(
          asset: asset,
          width: 300,
          height: 300,
        );
      }),
    );
  }

}

【问题讨论】:

  • 您如何上传您的数据?使用http 包?或dio?还是别的什么?
  • 我正在使用http包,谢谢,希望你能帮助我
  • 所以你有原始字节要上传 (asset.getByteData()),不是吗?那有什么问题呢?
  • 如果我打印 byteData print(byteData); 我得到了这个输出 Instance of 'Future&lt;ByteData&gt;'
  • 你要查看我发布的链接

标签: api flutter dart imagepicker


【解决方案1】:
Padding(
            padding: const EdgeInsets.all(18.0),
            child: InkWell(
              child: Text(
                'POST',
                style: TextStyle(fontSize: 18.0),
              ),
              onTap: () async {

 List<MultipartFile> multipart = List<MultipartFile>();

                for (int i = 0; i < images.length; i++) {
                  var path = await FlutterAbsolutePath.getAbsolutePath(images[i].identifier);

                }   

              },
            ),
          )

【讨论】:

    【解决方案2】:

    我正在使用下面的代码通过 file_picker: ^2.0.7 库来选择多个图像。 长按选择多张图像。选择图像后,您可以使用 f arr 来显示图像。

    List<File> f = List();
    
     RaisedButton(
                child: Text("Pick Image"),
                onPressed: () async {
                  FilePickerResult result = await FilePicker.platform.pickFiles(
                    allowMultiple: true,
                    type: FileType.custom,
                    allowedExtensions: ['jpg', 'png', 'jpeg'],
                  );
                  if (result != null) {
                    f = result.paths.map((path) => File(path)).toList();
                    setState(() {});
                    print(f);
                  }
                },
              ),

    用于图像上传和普通数据的示例 API 调用。图片上传栏应为 arr ( photo[] )。

     List<MultipartFile> newList = new List<MultipartFile>();
    
    
    Future<String> ImageUpload() async {
    
    var request = http.MultipartRequest('POST', url);
     request.headers["Authorization"] = pref.getString("token");
        request.headers["Accept"] = "application/json";
       //Image Data
      for (int i = 0; i < f.length; i++) {
          newList.add(await http.MultipartFile.fromPath('photo[]', f[i].path));
        }
        request.files.addAll(newList);
        
        Map<String, dynamic> data = Map<String, String>();
        //normal data
        data["user_id"] = user_id;
        data["project_id"] = pro_id;
        
        request.fields.addAll(data);
        var res = await request.send();
        
        if (res.statusCode == 200) {
          debugPrint("Status${res}");
          }else {
          debugPrint("status code${res}");
          }
          
        }
        
    Try This You can select and upload multiple images easily. Thank you.
    

    【讨论】:

      【解决方案3】:

      使用 multi_image_picker 4.7.14 库选择多个图像。使用下面的代码,您可以将选定的资产图像作为文件发送。 `

      //Inside Widget Builder
      FlatButton(
                  child: Image.asset(
                    "assets/images/camera.png",
                    color: Colors.grey,
                  ),
                  onPressed: loadAssets,
                ),
                
          SizedBox(
                        // height: SizeConfig.safeBlockHorizontal * 10,
                        height: MediaQuery.of(context).size.height / 2,
                        child: Column(
                          children: <Widget>[
                            Expanded(
                              child: buildGridView(),
                            ),
                          ],
                        ),
                      )

      List<File> fileImageArray = [];
        List<String> f = List();
        List<Asset> resultList = List<Asset>();
        List<Asset> images = List<Asset>();
        
        Future<void> loadAssets() async {
          try {
            resultList = await MultiImagePicker.pickImages(
              maxImages: 4,
              enableCamera: true,
              selectedAssets: images,
              cupertinoOptions: CupertinoOptions(takePhotoIcon: "chat"),
              materialOptions: MaterialOptions(
                actionBarColor: "#abcdef",
                actionBarTitle: "Example App",
                allViewTitle: "All Photos",
                useDetailsView: false,
                selectCircleStrokeColor: "#000000",
              ),
            );
          } on Exception catch (e) {
            error = e.toString();
          }
      
          if (!mounted) return;
      
          for (int i = 0; i < resultList.length; i++) {
            var path =
                await FlutterAbsolutePath.getAbsolutePath(resultList[i].identifier);
            print(path);
            f.add(File(path));
          }
      
          setState(() {
            images = resultList;
          });
      
          // return fileImageArray;
        }
      
      //image PreView
        Widget buildGridView() {
          return GridView.count(
            crossAxisCount: 4,
            children: List.generate(images.length, (index) {
              Asset asset = images[index];
              return AssetThumb(
                asset: asset,
                width: 50,
                height: 50,
              );
            }),
          );
        }

      API调用:上传图片的地方使用多部分文件

      List<MultipartFile> newList = new List<MultipartFile>();
          
        Future<String> multiImagePostAPI() async {
          var request = http.MultipartRequest('POST', url);
          request.headers["Authorization"] = pref.getString("token");
          request.headers["Accept"] = "application/json";
          
           for (int i = 0; i < f.length; i++) {
            newList.add(await http.MultipartFile.fromPath('photo[]', f[i].path));
          }
          request.files.addAll(newList);
           Map<String, dynamic> data = Map<String, String>();
            data["user_id"] = user_id;
            data["project_id"] = pro_id;
            data["title"] = titleController.text;
      
            request.fields.addAll(data);
      
            var res = await request.send();
           
           if (res.statusCode == 200) {
            debugPrint("Status$res");
           }else {
            debugPrint("status : $res");
            }
            
           
           }

      【讨论】:

      • 做了这个,但我收到了一个错误,上面写着E/flutter (16058): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: Bad state: Can't finalize a finalized MultipartFile.,我完全按照你所做的,请帮助
      • 请检查库版本。因为这个版本太旧了,可能是版本问题。
      【解决方案4】:

      您还可以使用 file_picker: ^1.5.0+2 库选择多个图像,并轻松获取所选图像的路径

      Future<int> getFilePath() async {
      try {
        files = await FilePicker.getMultiFile();
        if (files == '') {
          return 0;
        }
        else
        {
          setState(() {
            this._filePath = files;
            return 1;
          });
        }
      
      } on PlatformException catch (e) {
        print("Error while picking the file: " + e.toString());
      }
      

      }

      像这样使用 ListView Builder 显示选定的图像

                     ListView.builder(
                    scrollDirection: Axis.horizontal,
                    itemCount: _filePath.length,
                    itemBuilder: (context,c)
                    {
      
                      return Card(
                        child: Image.file(_filePath[c],
                          fit: BoxFit.fill,
                          width: 400,
                          height: 400,
      
                        ),
                      );
                    }
                ),
      

      【讨论】:

        猜你喜欢
        • 2021-05-04
        • 1970-01-01
        • 1970-01-01
        • 1970-01-01
        • 1970-01-01
        • 1970-01-01
        • 1970-01-01
        • 1970-01-01
        • 2021-01-31
        相关资源
        最近更新 更多