ProgressEvent

此文件需要技術審查。看看您能幫什麼忙。

我們的志工尚未將此文章翻譯為 正體中文 (繁體) 版本。加入我們,幫忙翻譯!

The ProgressEvent interface represents events measuring progress of an underlying process, like an HTTP request (for an XMLHttpRequest, or the loading of the underlying resource of an <img>, <audio>, <video>, <style> or <link>).

Constructor

ProgressEvent()
Creates a ProgressEvent event with the given parameters.

Properties

Also inherits properties from its parent Event.

ProgressEvent.lengthComputable Read only
Is a Boolean flag indicating if the total work to be done, and the amount of work already done, by the underlying process is calculable. In other words, it tells if the progress is measurable or not.
ProgressEvent.loaded Read only
Is an unsigned long long representing the amount of work already performed by the underlying process. The ratio of work done can be calculated with the property and ProgressEvent.total. When downloading a resource using HTTP, this only represent the part of the content itself, not headers and other overhead.
ProgressEvent.total Read only
Is an unsigned long long representing the total amount of work that the underlying process is in the progress of performing. When downloading a resource using HTTP, this only represent the content itself, not headers and other overhead.

Methods

Also inherits methods from its parent Event.

ProgressEvent.initProgressEvent()
Initializes a ProgressEvent created using the deprecated Document.createEvent("ProgressEvent") method.

Examples

The following example adds a ProgressEvent to a new XMLHTTPRequest and uses it to display the status of the request.

  var progressBar = document.getElementById("p"),
      client = new XMLHttpRequest()
  client.open("GET", "magical-unicorns")
  client.onprogress = function(pe) {
    if(pe.lengthComputable) {
      progressBar.max = pe.total
      progressBar.value = pe.loaded
    }
  }
  client.onloadend = function(pe) {
    progressBar.value = pe.loaded
  }
  client.send()

Specifications

Specification Status Comment
Progress Events
The definition of 'ProgressEvent' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 1.0 3.5 (1.9.1) 10.0 (Yes) (Yes)
initProgressEvent() No support[1] No support[2] 10.0 No support[4] No support[3]
Feature Android Android Webview Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support (Yes) (Yes) 1.0 (1.9.1) 10.0 (Yes) (Yes) (Yes)
initProgressEvent() No support[3] No support No support[2] 10.0 No support[4] No support[3] No support

[1] This feature was implemented in Chrome 1.0, but removed in Chrome 17.0.

[2] This feature was implemented in Gecko 1.9.1 (Firefox 3.5 / Thunderbird 3.0 / SeaMonkey 2.0), but removed in Gecko 22 (Firefox 22 / Thunderbird 22 / SeaMonkey 2.19).

[3] This feature was removed at some point.

[4] This feature was removed in Opera 15.0.

See also

  • The Event base interface.

文件標籤與貢獻者

 此頁面的貢獻者: jpmedley, Sebastianz, fscholz, teoli
 最近更新: jpmedley,