图像数据在React中的什么位置？

Question

我正在使用以下函数将图片上传到我们的应用程序中：

const result = await ImagePicker.launchCameraAsync({
                allowsEditing:true,
            });

这将返回以下对象：

Object {
  "cancelled": false,
  "height": 3200,
  "type": "image",
  "uri": "file:///data/user/0/host.exp.exponent/cache/ExperienceData/%2540sepbaa%252Frepoflex/ImagePicker/ff4dc82d-f14b-4b23-a81a-30e87c34d7e0.jpg",
  "width": 2400,
}

之后，我们需要将图像上传到我们的后台，但我们不知道图像数据在哪里。如果我们从前一个对象获取uri，它将返回以下内容：

Object {
  "_bodyBlob": Object {
    "_data": Object {
      "collector": Object {},
      "blobId": "c0e241fa-9b39-4aed-9860-793a393408dd",
      "lastModified": 0,
      "name": "ff4dc82d-f14b-4b23-a81a-30e87c34d7e0.jpg",
      "offset": 0,
      "size": 4864483,
      "type": "image/jpeg",
    },
  },
  "_bodyInit": Object {
    "_data": Object {
      "collector": Object {},
      "blobId": "c0e241fa-9b39-4aed-9860-793a393408dd",
      "lastModified": 0,
      "name": "ff4dc82d-f14b-4b23-a81a-30e87c34d7e0.jpg",
      "offset": 0,
      "size": 4864483,
      "type": "image/jpeg",
    },
  },
  "bodyUsed": true,
  "headers": Object {
    "map": Object {
      "content-type": "image/jpeg",
    },
  },
  "ok": false,
  "status": 0,
  "type": "default",
  "url": "",
}

我们需要将原始图像字节发送到我们的后端。这些数据存储在哪里？我们怎样才能找回它呢？

Answer 1

上传到后台，你需要这样做

const form = new FormData();

form.append({
  name: "SampleImage.jpg", // Name of file
  uri: "file:///data/user/0/host.exp.exponent/cache/ExperienceData/%2540sepbaa%252Frepoflex/ImagePicker/ff4dc82d-f14b-4b23-a81a-30e87c34d7e0.jpg", // URI of the file
  type: "image/jpg", // MIME type of the file
})

现在，您只需使用此表单作为主体来执行POST请求

同样在后端，你可以像这样访问它

req.file // Depends on the backend you are using ...