如何在Dart / Flutter中将图像发送到api?

时间:2018-07-03 19:43:03

标签: post dart flutter form-data

我看到了其他问题,但是那不是我想要的,我不想将图像上传到服务器,我不想转换为base64 ...

我只想以表单数据或其他形式发布文件并获取返回的信息。

我有这个,但是没有用:

  void onTakePictureButtonPressed() {
    takePicture().then((String filePath) {
      if (mounted) {
        setState(() {
          imagePath = filePath;
          videoController?.dispose();
          videoController = null;
        });

        http.post('http://ip:8082/composer/predict', headers: {
          "Content-type": "multipart/form-data",
        }, body: {
          "image": filePath,
        }).then((response) {
          print("Response status: ${response.statusCode}");
          print("Response body: ${response.body}");
        });


        if (filePath != null) showInSnackBar('Picture saved to $filePath');
      }
    });
  }

3 个答案:

答案 0 :(得分:9)

最简单的方法是像this post中那样发布多部分请求,然后将其发布到服务器。

确保将它们导入文件的开头:

import 'package:path/path.dart';
import 'package:async/async.dart';
import 'dart:io';
import 'package:http/http.dart' as http;
import 'dart:convert';

将此类添加到您的代码中的某个位置:

upload(File imageFile) async {    
      // open a bytestream
      var stream = new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));
      // get file length
      var length = await imageFile.length();

      // string to uri
      var uri = Uri.parse("http://ip:8082/composer/predict");

      // create multipart request
      var request = new http.MultipartRequest("POST", uri);

      // multipart that takes file
      var multipartFile = new http.MultipartFile('file', stream, length,
          filename: basename(imageFile.path));

      // add file to multipart
      request.files.add(multipartFile);

      // send
      var response = await request.send();
      print(response.statusCode);

      // listen for response
      response.stream.transform(utf8.decoder).listen((value) {
        print(value);
      });
    }

然后使用以下方式上传:

Upload(File(filePath));

在您的代码中:

void onTakePictureButtonPressed() {
    takePicture().then((String filePath) {
      if (mounted) {
        setState(() {
          imagePath = filePath;
          videoController?.dispose();
          videoController = null;
        });

       // initiate file upload
       Upload(File(filePath));

        if (filePath != null) showInSnackBar('Picture saved to $filePath');
      }
    });
  }

答案 1 :(得分:2)

如果要将图像发送到PHP Laravel Server。将size of the image发送到服务器时,请尝试减少它。我使用了Image Picker包来缩小图像的大小。

var image = await ImagePicker.pickImage(source: imageSource, imageQuality: 50, maxHeight: 500.0, maxWidth: 500.0);

然后使用该图像创建一个多部分文件,将其添加到表单数据中,然后使用带有dio库的发布请求将表单数据发送到服务器。有关发送数据,请参见@Elialber Lopes答案。

对我有用。

答案 2 :(得分:0)

 import 'package:dio/dio.dart'; //From 3.x.x version

    uploadImage(){
        var formData = FormData();
        formData.files.add(MapEntry("Picture", await MultipartFile.fromFile(data.foto.path, filename: "pic-name.png"), ));
        var response = await dio.client.post('v1/post', data: formdata);
    }