JavaScript-新File()无法正常工作 [英] JavaScript - New File() not working

问题描述

我正在尝试通过以下代码使用JavaScript将一些字符串写入文件中

I am trying to write some strings to a file using JavaScript through the following code

var txtfile ="../wp-content/plugins/MedicAdvisor/test.txt";
    var file = new File("hello",txtfile);
    //file = fopen("", 3);// opens the file for writing
    file.open("w");

    var currentrow = 0;
    var nextrow = 0;
    var type = " ";
    var noofrows = 0;
    var noofcells = 0;
    var contentarray;
    var row = document.getElementsByTagName('tr');
    //get all elements having input tag
    var inp = document.getElementsByTagName('input');
    // traverse through all input tags
    for (var i=2; i<inp.length; i++){
        // see if it is a heckbox
        if(inp[i].type == "checkbox"){
            // see if it is checked
            if(inp[i].checked == true){
                //index of current row
                currentrow = inp[i].parentNode.parentNode.rowIndex;
                //event type
                type = inp[i].parentNode.parentNode.cells[6].innerHTML.trim();
                if (type == "cycling_road_race"){
                    noofrows = 6;

                    for(var j=0; j<noofrows; j++){
                        noofcells = row[currentrow + j + 1].cells.length;
                        for (var k=1; k<noofcells; k++){
                            //alert (row[currentrow + j + 1].cells[k].innerHTML.replace('<br>' , ' '));
                            contentarray.push(row[currentrow + j + 1].cells[k].innerHTML.replace('<br>' , ' '));
                            file.writeln(row[currentrow + j + 1].cells[k].innerHTML.replace('<br>' , ' '));
                        }
                    }
                }
                else if (type == "cycling_criterium_or_circuit_race"){
                    noofrows = 6;
                }else if (type == "cycling_cyclocross"){
                    noofrows = 6;
                }else if (type == "running_race"){
                    noofrows = 6;
                }else if (type == "rugby_football_hockey"){
                    noofrows = 6;
                }else if (type == "music_festival"){
                    noofrows = 6;
                }else if (type == "manual_selection"){
                    noofrows = 5;
                }
            }
        }
    }

但是当我尝试执行此代码时出现以下错误

but I am getting following error when I try to execute this code

无法构造文件":第一个参数既不是数组，也不是它具有索引属性

Failed to construct 'File': The 1st argument is neither an array, nor does it have indexed properties

请帮助我解决此问题

推荐答案

如错误消息所示， File 构造函数期望将数组作为第一个参数.同样，第二个参数应仅是文件名和扩展名.您还可以将 type 设置为有效的 MIME 类型，将 lastModified 作为对象的属性，设置为 File 构造函数的第三个参数

As the error message indicated, File constructor expects an array as first parameter. Also the second parameter should only be the file name and extension. You can also set type as a valid MIME type and lastModified as properties of object at third parameter to File constructor.

var txtfile = "test.txt";
var file = new File(["hello"], txtfile
           , {type:"text/plain", lastModified: new Date().getTime()});

File.prototype 没有 .open 方法.您可以使用 File.prototype.slice()创建新的 File 对象，并将新数据连接到先前创建的 File 对象./p>

File.prototype does not have an .open method. You can use File.prototype.slice() to create a new File object and concatenate data new data to the previously created File object.

file = new File([file.slice(0, file.length), /* add content here */], file.name);

将 File 对象保存到服务器需要将 File 对象发布到服务器以读取文件数据的内容.

Saving a File object to server requires posting the File object to server to read the contents of the file data.

var request = new XMLHttpRequest();
request.open("POST", "/path/to/server");
request.send(file);

使用 php://input

$input = fopen("php://input", "rb");

请参见尝试使用输入类型文本传递超过524288字节的ToDataURL

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