我这里应用了vant-weapp插件，其实原理都是一样的，主要是调用微信的wx.uploadFile方法来实现；

//图片上传;html
<van-uploader max-count="1" 
	type="image" file-list="{{ fileList1 }}" use-before-read
	bind:before-read="beforeRead1" 
	bind:after-read="afterRead1" bind:delete="delete1" />
// 图片上传js

beforeRead1(event) {

	const {

		file,

		callback

	} = event.detail;

	callback(file.type === 'image');

},

delete1(event) {

	this.setData({

		fileList1: []

	})

},

afterRead1(event) {

	const {

		file

	} = event.detail;

	let that = this;

	let token = wx.getStorageSync('t') || "";

	wx.uploadFile({

		url: "http://127.0.0.0", // 这里写你们后台服务器的上传路径

		method: 'POST',

		header: {

			token:token,

			'content-type': "multipart/form-data; boundary=XXX"

		},

		filePath: file.url,

		name: 'file',

		formData: {

			bizType: 'SharedStores' //这里是额外的参数，后台不需要删除就行了

		},

		success(res) {

			let list = [{

				name: '图片',

				url: res.data

			}]

			that.setData({

				fileList1: list

			});

		},

	})

},

文件上传示例

//文件上传;html
<van-uploader max-count="1" accept="file" type="file" 
	file-list="{{ fileList3 }}" use-before-read
	deletable="{{ true }}" bind:before-read="beforeRead3" 
	bind:after-read="afterRead3" bind:delete="delete3">
	<view class="up-btn">+上传文件</view>
</van-uploader>
// 文件上传js

delete3(event) {

	this.setData({

		fileList3: []

	})

},

beforeRead3(event) {

	const {

		file,

		callback

	} = event.detail;

	callback(file.type === 'file');

},

afterRead3(event) {

	const {

		file

	} = event.detail;

	let that = this;

	let token = wx.getStorageSync('t') || "";

	wx.uploadFile({

		url: "http://127.0.0.0", // 这里写你们后台服务器的上传路径

		method: 'POST',

		header: {

			token:token,

			'content-type': "multipart/form-data; boundary=XXX"

		},

		filePath: file.url,

		name: 'file',

		formData: {

			bizType: 'SharedStores' //这里是额外的参数，后台不需要删除就行了

		},

		success(res) {

			let list = [{

				name: '文件',

				url: res.data

			}]

			that.setData({

				fileList3: list

			});

		},

	})

},