Question

我在下面有这个代码，并希望它显示文件上传的表单提交的进度。我想让它在我的网站上工作通过这个IP（24.148.156.217）访问它。因此，如果您看到网站，我希望在用户填写信息时显示进度条，然后点击提交按钮。然后进度条显示直到完成的时间。

<style>
<!--
.hide { position:absolute; visibility:hidden; }
.show { position:absolute; visibility:visible; }
-->
</style>

<SCRIPT LANGUAGE="JavaScript">

//Progress Bar script- by Todd King (tking@igpp.ucla.edu)
//Modified by JavaScript Kit for NS6, ability to specify duration
//Visit JavaScript Kit (http://javascriptkit.com) for script

var duration=3 // Specify duration of progress bar in seconds
var _progressWidth = 50; // Display width of progress bar.

var _progressBar = "|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||"
var _progressEnd = 5;
var _progressAt = 0;


// Create and display the progress dialog.
// end: The number of steps to completion
function ProgressCreate(end) {
 // Initialize state variables
 _progressEnd = end;
 _progressAt = 0;

 // Move layer to center of window to show
 if (document.all) { // Internet Explorer
  progress.className = 'show';
  progress.style.left = (document.body.clientWidth/2) - (progress.offsetWidth/2);
  progress.style.top = document.body.scrollTop+(document.body.clientHeight/2) - (progress.offsetHeight/2);
 } else if (document.layers) { // Netscape
  document.progress.visibility = true;
  document.progress.left = (window.innerWidth/2) - 100+"px";
  document.progress.top = pageYOffset+(window.innerHeight/2) - 40+"px";
 } else if (document.getElementById) { // Netscape 6+
  document.getElementById("progress").className = 'show';
  document.getElementById("progress").style.left = (window.innerWidth/2)- 100+"px";
  document.getElementById("progress").style.top = pageYOffset+(window.innerHeight/2) - 40+"px";
 }

 ProgressUpdate(); // Initialize bar
}

// Hide the progress layer
function ProgressDestroy() {
 // Move off screen to hide
 if (document.all) { // Internet Explorer
  progress.className = 'hide';
 } else if (document.layers) { // Netscape
  document.progress.visibility = false;
 } else if (document.getElementById) { // Netscape 6+
  document.getElementById("progress").className = 'hide';
 }
}

// Increment the progress dialog one step
function ProgressStepIt() {
 _progressAt++;
 if(_progressAt > _progressEnd) _progressAt = _progressAt % _progressEnd;
 ProgressUpdate();
}

// Update the progress dialog with the current state
function ProgressUpdate() {
 var n = (_progressWidth / _progressEnd) * _progressAt;
 if (document.all) { // Internet Explorer
  var bar = dialog.bar;
  } else if (document.layers) { // Netscape
  var bar = document.layers["progress"].document.forms["dialog"].bar;
  n = n * 0.55; // characters are larger
 } else if (document.getElementById){
                var bar=document.getElementById("bar")
        }
 var temp = _progressBar.substring(0, n);
 bar.value = temp;
}

// Demonstrate a use of the progress dialog.
function Demo() {
 ProgressCreate(10);
 window.setTimeout("Click()", 100);
}

function Click() {
 if(_progressAt >= _progressEnd) {
  ProgressDestroy();
  return;
 }
 ProgressStepIt();
 window.setTimeout("Click()", (duration-1)*1000/10);
}

function CallJS(jsStr) { //v2.0
  return eval(jsStr)
}

</script>

<SCRIPT LANGUAGE="JavaScript">

// Create layer for progress dialog
document.write("<span id=\"progress\" class=\"hide\">");
 document.write("<FORM name=dialog id=dialog>");
 document.write("<TABLE border=2  bgcolor=\"#FFFFCC\">");
 document.write("<TR><TD ALIGN=\"center\">");
 document.write("Progress<BR>");
 document.write("<input type=text name=\"bar\" id=\"bar\" size=\"" + _progressWidth/2 + "\"");
 if(document.all||document.getElementById)  // Microsoft, NS6
  document.write(" bar.style=\"color:navy;\">");
 else // Netscape
  document.write(">");
 document.write("</TD></TR>");
 document.write("</TABLE>");
 document.write("</FORM>");
document.write("</span>");
ProgressDestroy(); // Hides

</script>


<form name="form1" method="post">
<center>
<input type="button" name="Demo" value="Display progress" onClick="CallJS('Demo()')">
</center>
</form>

<a href="javascript:CallJS('Demo()')">Text link example</a>

Answer 1

麻烦的是，JavaScript不知道（并且至少在HTML4中无法知道）上传的当前进度状态。所以，你有三种可能性：

您可以让您的JS定期轮询服务器以获取有关进度的信息（例如，使用Ajax，或在单独的窗口中）
您可以使用JS之外的其他内容（例如Flash或Java）
或者您可以制作一个不能准确反映进度的动画（例如沙漏，跳舞点或来回的条形图）。

如何将进度条嵌入到HTML表单中？

1 个答案: