前端请求设置 responseType: “blob”

后台接口返回的文件流如下：

拿到后端返回的文件流后：
预览

<iframe  :src="previewUrl" frameborder="0" style="width: 500px; height: 500px;"></iframe>

1、预览

view(data) {// 文件类型            let fileType = this.fileName.slice(this.fileName.length - 3).toUpperCase();let myBlob = '';//不同文件类型设置不同的type            if (fileType == 'PDF') {myBlob = new window.Blob([data], { type: 'application/pdf' });} else {myBlob = new window.Blob([data], { type: 'image/png' });}const previewUrl = window.URL.createObjectURL(myBlob);this.previewUrl = previewUrl;// iframe预览// window.open(previewUrl, '_blank');// 浏览器新打开窗口        
},

2、下载

// 下载        
downFile() {var data = this.fileData;var fileType = this.fileName.slice(this.fileName.length - 3).toUpperCase();var blob = "";if (fileType == 'PDF') {blob = new window.Blob([data], { type: 'application/pdf' });} else if (fileType == 'PNG') {blob = new window.Blob([data], { type: 'image/png' });}const a = document.createElement("a");const objectUrl = URL.createObjectURL(blob);a.setAttribute("href", objectUrl);a.setAttribute("download", this.fileName);a.click();URL.revokeObjectURL(a.href); // 释放url        
}