Question

始终在数组中上传第一个文件我循环遍历图像文件列表，通过http发送它们作为上传

for(var j=0;j<images.length;j++){
    (function(idx,images){
        console.log("idx"+JSON.stringify($scope.Files)+"====="+JSON.stringify(images));
        var data = {"image":images[idx]};
        var payload = new FormData();
        for(var key in data){
            payload.append(key, data[key]);
        }

        $http({
            url: uploadUrl,
            method: 'POST',
            data: payload,
            //assign content-type as undefined, the browser
            //will assign the correct boundary for us
            headers: {'token':token,'Access-Control-Allow-Origin': '*','Content-Type': undefined},
            //prevents serializing payload.  don't do it.
            transformRequest: angular.identity
        }).then(fucntion(response){
            console.log("response :" + JSON.stringify(response));
        });
    })(j,images);
}

Answer 1

顺序处理异步操作的另一种方法可能是使用递归函数来减少图像数组，如果你喜欢做不同的事情。

function upload(images) {

    var image = images[0]; //the  fist item in the array of images

    var data = {
        image: image
    };

    var payload = new FormData();

    payload.append('image', data);

    $http({
        url: uploadUrl,
        method: 'POST',
        data: payload
    }).then(function (response) {

        console.log(response);

         images.shift(); //Edit: Fixed this bit

        if (images.length) {
            upload(images); //call the upload function again
        }
        else {
            console.log('all images uploaded'); //When the arrays length is 0 all images have been uploaded
        }

    });
}

upload(myArrayOfImagesInHere); //Initially call the function here with an array of images or things you want uploaded.

Answer 2

为了让您顺序请求，您可以使用承诺。

aws s3 cp exe_file.exe s3://cdn/exe_file.exe --content-type "application/x-msdownload" --content-disposition "attachment; filename=\"exe_file.exe\"; filename*=utf-8''exe_file.exe" --metadata-directive REPLACE

Answer 3

您可以使用$q.all作为执行多个异步请求的简便方法。

var promises = [];
for(var j=0;j<images.length;j++){
    (function(idx,images){
        console.log("idx"+JSON.stringify($scope.Files)+"====="+JSON.stringify(images));
        var data = {"image":images[idx]};
        var payload = new FormData();
        for(var key in data){
            payload.append(key, data[key]);
        }

        var promise = $http({
            url: uploadUrl,
            method: 'POST',
            data: payload,
            //assign content-type as undefined, the browser
            //will assign the correct boundary for us
            headers: {'token':token,'Access-Control-Allow-Origin': '*','Content-Type': undefined},
            //prevents serializing payload.  don't do it.
            transformRequest: angular.identity
        });
        promises.push(promise)
    })(j,images);
}

$q.all(promises)
.then(function(responses) {
    // responses available here
})

如何在文件列表的循环中以角度进行同步http请求？

3 个答案: