标签:inpu lse alert end reader val pex foreach comm
Salesforce图片上传的方式可通过自带组件apex:inputFile及html标签input type="file"实现。
1、效果
2、apex:inputFile实现
采用标准组件inputFile并将值赋给页面变量(view state)Picture
<apex:pageBlockSection columns="1"> <apex:inputFile value="{!Picture}" accept="image/*" /> </apex:pageBlockSection> <apex:pageBlockButtons> <apex:commandButton value="Save" action="{!save}" /> </apex:pageBlockButtons>
public with sharing class Test_HpcUploadImg { public blob Picture { get; set; } public PageReference save() { ErrorMessage = ‘‘; try { if (picture != null) { String url = CN_SPR_UploadAzureHelper.UploadToAzure(picture,‘.jpg‘,‘application/octet-stream‘); ErrorMessage=url;
注意:
此种方式图片大小限制为170KB,超过则提示“Maximum view state size limit (170KB) exceeded. Actual view state size for this page was 293.157KB”
3、input type="file"实现
<div class="slds-col slds-size_1-of-1 slds-p-horizontal_medium"> <img id="imgPreview_csp" style="width:180px;height:180px;" src="{!URLFOR($Resource.India_Content, ‘img/sample_picture.png‘)}" /> </div> <div class="slds-col slds-size_1-of-1 slds-p-horizontal_medium" style="margin-top:5px;"> <input type="file" id="fileImg_csp" value="" filename="fileImg_csp" style="display:none;" accept=".jpg,.jpeg,.png" /> <button class="slds-button slds-button_neutral" id="btnSelecttPic" style="display:none;">Select a Picture</button> <input type="Button" value="Upload" id="btnSave_csp" class="slds-button slds-button_brand" style="display:none;" /> </div>
//选择图片,马上预览 function changeImg(obj) { var file = obj.files[0]; var reader = new FileReader(); //读取文件过程方法 reader.onloadstart = function (e) { //开始读取 } reader.onprogress = function (e) { //正在读取中 } reader.onabort = function (e) { //中断读取 } reader.onerror = function (e) { //读取异常 } reader.onload = function (e) { //成功读取 var files = document.getElementById(‘fileImg_csp‘).files; var fileName = files[0].name; //判断文件后缀 if (!(/\.jpg$/.test(fileName) || /\.jpeg$/.test(fileName) || /\.png$/.test(fileName))) { Messages.add(Messages.Type.error, "JPG,PNG images only supported"); return; } var img = document.getElementById("imgPreview_csp"); img.src = e.target.result; //或者 img.src = this.result; //e.target == this } reader.readAsDataURL(file);//必须要加 } //上传 function saveImg() { Messages.clear(); var maxFileSize = 1572864; //1.5M=1.5*1024*1024 var attachmentBody; //附件内容 var attachmentName; //附件名称 var fileSize; //附件大小 var Files = document.getElementById(‘fileImg_csp‘).files; var File = Files[0]; if (File != undefined) { if (File.size <= maxFileSize) { attachmentName = File.name; //判断文件后缀 if (!(/\.jpg$/.test(attachmentName) || /\.jpeg$/.test(attachmentName) || /\.png$/.test(attachmentName))) { Messages.add(Messages.Type.error, "JPG,PNG images only supported"); return; } // debugger; var fileReader = new FileReader(); fileReader.readAsBinaryString(File); fileReader.onloadend = function (e) { Spinner.show(); //原始对象 // attachmentBody = this.result; //Base64(btoa用于将对象创建为base-64 编码的字符串) attachmentBody = window.btoa(this.result); //Base64编码转换为Blob // attachmentBody=getBlob(window.btoa(this.result)); Visualforce.remoting.Manager.invokeAction( ‘{!$RemoteAction.IN_ChillerStandardPicture_Controller.UploadPicture}‘, attachmentName, attachmentBody, getQueryParams(), function (result, event) { Spinner.hide(); console.log(result); // alert(‘Upload Successfully‘); Messages.add(Messages.Type.info, "Upload Successfully"); }); } fileReader.onerror = function (e) { // alert("Upload failed"); Messages.add(Messages.Type.error, "Upload failed"); } fileReader.onabort = function (e) { // alert("Upload failed"); Messages.add(Messages.Type.error, "Upload failed"); } fileReader.onload = function (e) { } } else { // alert("Maximum upload of 1.5M files is allowed"); Messages.add(Messages.Type.error, "Maximum upload of 1.5M files is allowed"); } } else { // alert("Please select a file first"); Messages.add(Messages.Type.error, "Please select a file first"); } }
//上传图片 @RemoteAction public static String UploadPicture(String attachmentName,String attachmentBody,String queryParam) { try { //反序列化 IN_AvailablilityAbi_Controller.QueryRequestParam req = (IN_AvailablilityAbi_Controller.QueryRequestParam)JSON.deserialize(queryParam, IN_AvailablilityAbi_Controller.QueryRequestParam.class); //上传图片到Azure // Blob blobFile= Blob.valueOf(attachmentBody);//将Base64编码的字符串转换为Blob【此处有问题】 Blob blobFile = EncodingUtil.base64Decode(attachmentBody);//将Base64编码的字符串转换为Blob string fileSuffix= attachmentName.substring(attachmentName.indexOf(‘.‘));//后缀 String url = CN_SPR_UploadAzureHelper.UploadToAzure(blobFile,fileSuffix,‘application/octet-stream‘);
注意:
此种方式测试了1.7M的图片可正常上传,5M则提示超出了大小限制(具体限制大小需再做测试)
4、建议
建议采用input type="file"实现的方式,且将图片以Base64传输到后端再进行流的转换。如果在前端进行Blob的转换需要考虑后端接收流的方式。
JS将Base64编码转换为Blob的实现如下:
//Base64编码转换为Blob function getBlob(text) { var buffer = new Uint8Array(text.length); var pecent = 0, loop = null; for (var i = 0; i < text.length; i++) { buffer[i] = text.charCodeAt(i); } var format = ‘image/jpeg‘; try { return new Blob([buffer], { type: format }); } catch (e) { var bb = new (window.BlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder); buffer.forEach(function (buf) { bb.append(buf); }); return bb.getBlob(format); } }
标签:inpu lse alert end reader val pex foreach comm
原文地址:https://www.cnblogs.com/hepc/p/10891711.html