filereader | 易学教程

How can I create a canvas imageData array from an arrayBuffer representation of a JPG

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问题 First of all I am aware there are standard methods of achieving this (readAsDataURL and drawImage), but unfortunately they are not usable for this specific use case. I am reading an image using the filereader API as an arraybuffer like so: var reader = new fileReader(); reader.onload = function(e){ var byteArray = new Uint8ClampedArray(e.target.result); //do stuff to this array } reader.readAsArrayBuffer(file); I am then creating a clampedarray with this returned data. What I want to be able

Java can't find file when running through Eclipse

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When I run a Java application that should be reading from a file in Eclipse, I get a java.io.FileNotFoundException , even though the file is in the correct directory. I can compile and run the application from the command line just fine; the problem only occurs in Eclipse, with more than one project and application. Is there a setting I need to change in the run configurations or build paths to get it to find the file correctly? The problem is most likely that your application is using a relative pathname. As @BalusC says, relative pathnames can be problematic. But IMO, he goes way too far

FileReader and CodeMirror Load File Complication

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问题 Default CodeMirror HTML Editor with Preview - http://jsfiddle.net/D9MvH/1/ - http://liveweave.com/zSqCfA Load File in CodeMirror with FileReader API - http://liveweave.com/VvsXN9 Here's a very simple example of what I'm trying to do. (Save function don't work on these online editors, but the import file function works on this simple editor) - http://liveweave.com/MrUBfZ My problem is when I click my input file form to browse for a file. I choose the HTML document to be opened and it won't

Getting Data from FileReader in Angular 2

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问题 I am trying to create an upload form in Angular 2 ts (2.2.1), that allows the upload of e.g. a CSV file, but instead of the file being sent straight to a http service I want the file first to be validated in the browser. So far I can already upload a file and print it in the console with this code: Html input for file upload <input type="file" (change)="changeListener($event)" #input /> In my angular component I have set up the eventListner and the File reader. export class UploadComponent {

Return the Array of Bytes from FileReader()

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问题 I need some help returning the "bytes" variable from this function below to be used as input in another function. function openfile() { var input = document.getElementById("files").files; var fileData = new Blob([input[0]]); var reader = new FileReader(); reader.readAsArrayBuffer(fileData); reader.onload = function(){ var arrayBuffer = reader.result var bytes = new Uint8Array(arrayBuffer); console.log(bytes); } I'd like to get the return of the above function and use the array of bytes as

Posting File Input as FileReader Binary Data through AJAX Post

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I am trying to post an attachment uploaded to an HTML file input to a web page through a rest API. The API documentation states that the post is a straight binary content as the body of the HTTP request, not a form file upload. My code is as follows: $('#_testButton').bind('click', function () { var file = document.getElementById('_testFile').files[0] var reader = new FileReader(); reader.onload = function () { $.ajax({ url: '/attachmentURL', type: 'POST', data: reader.result }) } reader.readAsBinaryString(file) }) I need this to work for a number of different mimeTypes, so I didn't declare it

Read and base64 encode a binary file

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问题 I'm trying to read a binary file from the filesystem and then base64 encode it in JavaScript. I'm using the FileReader API to read the data and the base64 encoder found here. The code I have seems close to working, the problem is that the generated base64 data is wrong. Here's what I've got so far: function saveResource() { var file = $(".resourceFile")[0].files[0]; var reader = new FileReader(); reader.onload = function(evt) { var fileData = evt.target.result; var bytes = new Uint8Array

Is it possible to load a file with JS/HTML5 FileReader on non served page?

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问题 I want to create a simple game in HTML5/JS and I don't want the user to run any webserver or to have to connect to a website. (just an HTML page) But it looks like FileReader can only be used on files type inputs. Is it possible to have only two files : index.html and foo.txt side by side and to read foo.txt from index.html with something like : // No input needed, I know waht I want to read var my_file = new File("foo.txt"); var reader = new FileReader(); alert( reader.readAstext( my_file,

How to read a file in AngularJS?

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Is it possible to read files in AngularJS? I want to place the file into an HTML5 canvas to crop. I was thinking of using a directive? This is the javscript code I want to put into my directive: function readURL(input) { if (input.files && input.files[0]) { var reader = new FileReader(); reader.onload = function (e) { $('#blah').attr('src', e.target.result); } reader.readAsDataURL(input.files[0]); } } Cherniv Yes, directives is a right way, but it looks little bit different: .directive("ngFileSelect",function(){ return { link: function($scope,el){ el.bind("change", function(e){ $scope.file =

异常处理Exception

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Day10 Java ** 一.异常处理的模板** /** 异常处理处理运行过程中出现的不可控的错误：error 是程序更健壮 *Exception1- 处理模式 try{ 执行的代码可能出现异常一旦出现异常系统自动为我们创建一个异常对象并抛出 }catch(NullPointerException e){ 如果需要自己处理异常就catch }catch(IOException e){ 如果有多个异常可以使用多个catch来捕获如果有多个异常 catch 的顺序从小到大 }catch(Exception1 e){ }finally{ 不管有没有异常finally 都会被执行处理资源会收网络连接数据库连接 I/O流 } 二.主要的方法 *** 1.try. 如果异常出现后面的代码不执行 *try 代码块不要抓太多代码 2.使用throws抛出异常给外部处理 3.当特殊情况出现自己可以选择抛出异常 throw 4.自定义异常类三.代码*实际例子 public class Exception1 { public static void main(String[] args){ int a = 0; int b = 20; // int c = b/a; //❌ FileReader fr = null; try{ int c = b/a; System