小程序实现选择图片九宫格带预览

效果图

数据：

依赖接口wx.upload、chooseImage与preview 数据请求通过LeanCloud完成

图片选择：

https://mp.weixin.qq.com/debug/wxadoc/dev/api/media-picture.html#wxchooseimageobject

前端处理：

1.保存images数组为已选择图片 2.选择了更多图片后concat数组 3.预览图集 4.leancloud上传多图，目测顺序一致

js代码

const AV = require('../../../utils/av-weapp.js')
var that;
Page({
    data: {
        images: [],
        uploadedImages: [],
        imageWidth: getApp().screenWidth / 4 - 10
    },
    onLoad: function (options) {
        that = this;
        var objectId = options.objectId;
        console.log(objectId);
    },
    chooseImage: function () {
        // 选择图片
        wx.chooseImage({
            sizeType: ['compressed'], 
            sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有
            success: function (res) {
                // 返回选定照片的本地文件路径列表，tempFilePath可以作为img标签的src属性显示图片
                var tempFilePaths = res.tempFilePaths;
                console.log(tempFilePaths);
                that.setData({
                    images: that.data.images.concat(tempFilePaths)
                });
            }
        })
    },
    previewImage: function () {
        // 预览图集
        wx.previewImage({
            urls: that.data.images
        });
    },
    submit: function () {
        // 提交图片，事先遍历图集数组
        that.data.images.forEach(function (tempFilePath) {
            new AV.File('file-name', {
                blob: {
                    uri: tempFilePath,
                },
            }).save().then(
                // file => console.log(file.url())
                function(file) {
                    // 先读取
                    var uploadedImages = that.data.uploadedImages;
                    uploadedImages.push(file.url());
                    // 再写入
                    that.setData({
                        uploadedImages: uploadedImages
                    });
                    console.log(uploadedImages);
                }
            ).catch(console.error);
        });
        wx.showToast({
            title: '评价成功',
            success: function () {
                wx.navigateBack();
            }
        });
    },
    delete: function (e) {
        var index = e.currentTarget.dataset.index;
        var images = that.data.images;
        images.splice(index, 1);
        that.setData({
            images: images
        });
    }
})

wxml代码

<view class="gallery">
    <view class="item" wx:for="{{images}}" wx:key="">
        <image style="width: {{imageWidth}}px; height: {{imageWidth}}px" src=" {{item}}" bindtap="previewImage" mode="aspectFill" />
        <!-- 删除按钮 -->
        <view class="delete" bindtap="delete" data-index="{{index}}"><image style="left: {{imageWidth / 2 - 10}}px;" src="/images/icon_delete.png" /></view>
    </view>
    <view class="item">
        <image style="width: {{imageWidth}}px; height: {{imageWidth}}px" src="/images/icon_add.png" class="button-upload" bindtap="chooseImage" />
    </view>
</view>
<button type="primary" bindtap="submit">提交</button>

wxss代码

/*画廊*/
.gallery {
    /*margin-bottom: 100rpx;*/
    display: flex;
    justify-content: flex-start;
    flex-wrap: wrap;
}

/*每张图片所占容器*/
.item {
    position: relative;
    margin: 5px;
}

/*删除按钮*/
.delete {
    position: absolute;
    height: 20px;
    bottom: 0;
    width: 100%;
    background: #ccc;
    opacity: .8;
}

.delete image {
    position: absolute;
    width: 20px;
    height: 20px;
}

源码下载：https://git.oschina.net/dotton/lendoo-wx，本文涉及代码存于/pages/member/evalute文件夹中。