王新阳

普通的jQuery中的ajax请求后台，并不能处理Blob类型的数据，这里用的原生的XMLHttpRequest请求后台

转自：https://blog.csdn.net/lf1934305268/article/details/123401275

     var xhr = new XMLHttpRequest();
            xhr.open("get",url, true);
            xhr.responseType = "blob";
            xhr.onload = function() {

                if (this.status == 200) {
                    $.unblockUI();
                    var blob = this.response;
                    if(blob.type == "text/html"){
                        return false
                    }
                    var fileName = "aaaa.xlsx";
                    if(window.navigator.msSaveOrOpenBlob){            // IE浏览器下
                        navigator.msSaveBlob(blob, fileName);
                    } else {
                        var  link = document.createElement("a");
                        link.href = window.URL.createObjectURL(blob);
                        link.download = fileName;
                        link.click();
                        window.URL.revokeObjectURL(link.href);
                    }
                }else{
                }
            }

另：IE浏览器已不再使用，可以删除对IE浏览器的判断

我的代码：

	var xhr = new XMLHttpRequest();
	xhr.timeout = 600000; //设置超时毫秒数(0为永不超时)
	xhr.open('GET', url, true);
	xhr.responseType = 'blob';
	xhr.onload = function(){
		if(this.status != 200){
			return;
		}
		var blob = this.response;
		if(blob.type == "text/html"){
			console.log('error');
			return false;
		}
		var allow_type=['video/quicktime','video/mp4'];
		if(allow_type.indexOf(blob.type)==-1){
			console.log('content-type not allowed');
			return false;
		}

		console.log(filename+' 下载完成，大小'+blob.size+'字节');

		var url = window.URL.createObjectURL(blob);
		var a = document.createElement('a');
		a.href = url;
		a.download = filename;
		a.click();
		window.URL.revokeObjectURL(a.href);
	}
	xhr.onerror = function(){
		console.log('error');
		console.log(this.status);
		console.log(this);
	}
	xhr.ontimeout = function(){
		console.log('timeout');
		console.log(this.status);
		console.log(this);
	}
	xhr.send();