在Vue.js中上载图像之前如何显示图像?
在接下来的教程中,我制作了这个组件,它可以一次上传多个图像,并显示要上传的文件名 这很好,但我想知道如何显示照片(理想情况下调整到一定的最大宽度)而不是它们的文件名在Vue.js中上载图像之前如何显示图像?,vue.js,image-uploading,Vue.js,Image Uploading,在接下来的教程中,我制作了这个组件,它可以一次上传多个图像,并显示要上传的文件名 这很好,但我想知道如何显示照片(理想情况下调整到一定的最大宽度)而不是它们的文件名 <div v-if="showUploadPhotoModal"> <transition name="modal"> <div class="modal-mask"> <div class="modal-wrapper
<div v-if="showUploadPhotoModal">
<transition name="modal">
<div class="modal-mask">
<div class="modal-wrapper">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header"><strong>{{username}}</strong>
<h6 class="modal-title">Upload Photos <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-image"><rect x="3" y="3" width="18" height="18" rx="2" ry="2"></rect><circle cx="8.5" cy="8.5" r="1.5"></circle><polyline points="21 15 16 10 5 21"></polyline></svg>
</h6>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true" @click="showUploadPhotoModal = false">×</span>
</button>
</div>
<div class="modal-body">
<form @submit.prevent="sendFile" enctype="multipart/form-data">
<div class="form-group">
<textarea class="form-control" rows="5" v-model="title" placeholder="Title"></textarea>
</div>
<div v-if="fileError" class="alert alert-danger">{{message}}</div>
<label class="upload-btn"><br>
<span>
<img class="logo img-responsive" src="../assets/images/upload.png">
<br>
</span>
Upload Files <input multiple type="file" @change="selectFile" ref="files" hidden>
<br>
</label>
</form>
</div>
<div class="field">
<div v-for="(file, index) in files" :key="index" class="row photo-list" >
<div class="col-10 col-push-6">
<div :class="`text-right ${file.invalidMessage ?'red':'black'}`">{{file.name}}
<span v-if="file.invalidMessage!=''"> <small>{{file.invalidMessage}}</small> </span>
</div>
</div>
<div class="col-2">
<div class="text-left">
<a @click.prevent="files.splice(index, 1);uploadFiles.splice(index, 1)" class="remove-btn"> <strong >×</strong></a>
</div>
</div>
</div>
</div>
<span @click="sendFile" class="btn btn-primary">Send</span>
</div>
</div>
</div>
</div>
</transition>
</div>
data () {
return {
showUploadPhotoModal: false,
files: [],
uploadFiles: [],
title: "",
message: "",
fileError: false,
}
},
methods: {
selectFile() {
const files = this.$refs.files.files;
this.uploadFiles = [...this.uploadFiles, ...files];
this.files = [
...this.files,
..._.map(files, file => ({
name: file.name,
type: file.type,
invalidMessage: this.validate(file)
}))
];
},
validate(file) {
const allowedTypes = ["image/jpeg", "image/png", "image/gif"];
if(!allowedTypes.includes(file.type)) {
return "Not an image"
}
return "";
},
sendFile() {
const formData = new FormData();
formData.append('title', this.title);
formData.append('token', this.token);
_.forEach(this.uploadFiles, file => {
if(this.validate(file)==="") {
formData.append('files', file);
}
});
axios.post(this.BASE_URL + "/api/post", formData)
.then(res => {
console.log('res data is:', res.data);
this.files=[];
this.uploadFiles=[];
})
.catch(err => {
console.log('error is', err.response.data.error)
this.fileError = true;
});
}
},
{{username}}
上传照片
&时代;
{{message}}
上传文件
{{file.name}
{{file.invalidMessage}
&时代强>
发送
数据(){
返回{
showUploadPhotoModal:false,
文件:[],
上载文件:[],
标题:“,
消息:“”,
fileError:false,
}
},
方法:{
选择文件(){
const files=this.$refs.files.files;
this.uploadFiles=[…this.uploadFiles,…files];
此文件的长度=[
…这个文件,
.map(文件,文件=>({
name:file.name,
type:file.type,
invalidMessage:this.validate(文件)
}))
];
},
验证(文件){
const allowedTypes=[“image/jpeg”、“image/png”、“image/gif”];
如果(!allowedTypes.includes(file.type)){
返回“非图像”
}
返回“”;
},
sendFile(){
const formData=new formData();
formData.append('title',this.title);
formData.append('token',this.token);
_.forEach(this.uploadFiles,file=>{
如果(此.validate(文件)==“”){
formData.append('files',file);
}
});
axios.post(this.BASE_URL+“/api/post”,formData)
。然后(res=>{
log('res数据为:',res.data);
this.files=[];
this.uploadFiles=[];
})
.catch(错误=>{
console.log('error is',err.response.data.error)
this.fileError=true;
});
}
},
为了处理这个问题,我从以下布局开始:
<div id="app" v-cloak>
<input type="file" multiple accept="image/*"
@change="handleSelects" name="images">
<div v-for="image in images">
<img :src="image" class="preview">
</div>
</div>
所以handleSelects做了一些事情。首先,它重置缩略图(this.images)。然后查看输入中选择的文件,检查它们是否为图像,并为每个文件设置文件读取器。对于每个文件,它都会获得一个数据url,然后将该url添加到该图像数组中,以便可以创建预览
你可以在这里看到完整的代码笔:所以不赞成出现博客帖子的答案,但我在这里介绍了一种方法(不是Vue!)-。这有帮助吗?如果是的话,我会把它作为一个答案贴出来@RaymondCamden,请查看我的实现问题:
const app = new Vue({
el:'#app',
data:{
images:[]
},
methods:{
handleSelects(e) {
this.images = [];
let fileList = Array.prototype.slice.call(e.target.files);
fileList.forEach(f => {
if(!f.type.match("image.*")) {
return;
}
let reader = new FileReader();
let that = this;
reader.onload = function (e) {
that.images.push(e.target.result);
}
reader.readAsDataURL(f);
});
}
}
})