Javascript 从ActiveX组件调用的JS回调如果不在主代码流中,则不会触发
我有一个ActiveX组件,可以扫描照片,将文件保存到客户端硬盘上的临时文件中,然后上传照片 我有一个“TwainMan”实例,它执行扫描部分,扫描完成后触发“ImageScanned”事件。这是我的主要代码流:Javascript 从ActiveX组件调用的JS回调如果不在主代码流中,则不会触发,javascript,c#,callback,activex,dom-events,Javascript,C#,Callback,Activex,Dom Events,我有一个ActiveX组件,可以扫描照片,将文件保存到客户端硬盘上的临时文件中,然后上传照片 我有一个“TwainMan”实例,它执行扫描部分,扫描完成后触发“ImageScanned”事件。这是我的主要代码流: scanner = new TwainMan(); scanner.ImageScanned += new ImageScannedEventHandler(Scanner_ImageScanned); 执行此操作的代码放入EventHandler委托方法“Scanner\u Ima
scanner = new TwainMan();
scanner.ImageScanned += new ImageScannedEventHandler(Scanner_ImageScanned);
执行此操作的代码放入EventHandler委托方法“Scanner\u ImageScanned”:
在TriggerJSCallback方法中,我只触发我的JS回调:
private void TriggerJSCallback()
{
EventHandler DataPreparingFinished = this.DataPreparingFinished;
if (null != DataPreparingFinished) { DataPreparingFinished(this.tempFileName); }
}
请注意,如果我从主流程内触发JSCallback“DataPreparingFinished”,JS回调侦听器(在我的html页面中定义)工作正常,但是如果触发器“DataPreparingFinished”是从“Scanner\u ImageScanned”委托内触发的,而不是从主代码流触发的,则会出现问题
我做错了什么?有人能帮忙吗
下面是html页面中标记内的JS回调定义
<script for="AXTwain" event="DataPreparingFinished(args)" language="javascript" type="text/javascript">
function AXTwain::DataPreparingFinished(args) {
alert("JS ALERT: SUCCESS!!! JS Callback working properly." + args);
// alert("The temp file is stored on: " + AXTwain.TempFileName);
}
</script>
函数AXTwain::DataPreparingFinished(args){
警报(“JS警报:成功!!!JS回调工作正常。”+args);
//警报(“临时文件存储在:“+AXTwain.TempFileName”上);
}
如果我能展示更多的代码,也许会更好,这样你就能更好地了解我的问题到底是什么 让我们从顶部开始 下面是我的HTML页面,其中包括我的ActiveXObject实例化和JS回调/侦听器函数
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>ActiveX TWAIN test page</title>
<object id="AXTwain" name="AXTwain" classid="clsid:d8ea830e-38b0-4f3b-8be4-39c417c27583"></object>
</head>
<body onload="myload();">
<h1 style="color:green;">AXTwain test page</h1>
<script type ="text/javascript">
function myload() {
if (AXTwain != null) {
AXTwain.AcquireImage();
}
}
</script>
<script for="AXTwain" event="DataPreparingFinished(args)" language="javascript" type="text/javascript">
// The "for" attribute should be set to the name of instance of your COM component.
// The "event" attribute should be set to the JavaScript function signature for the event.
// The name of the JavaScript function is the instance name of your COM component, followed
// by double colons, followed by the JavaScript signature of the event.
function AXTwain::DataPreparingFinished(args) {
alert("JS ALERT: SUCCESS!!! JS Callback working properly." + args);
}
</script>
</body>
</html>
ActiveX TWAIN测试页
AXTwain测试页
函数myload(){
if(AXTwain!=null){
AXTwain.AcquireImage();
}
}
//“for”属性应设置为COM组件实例的名称。
//“event”属性应设置为事件的JavaScript函数签名。
//JavaScript函数的名称是COM组件的实例名称,后跟
//使用双冒号,后跟事件的JavaScript签名。
函数AXTwain::DataPreparingFinished(args){
警报(“JS警报:成功!!!JS回调工作正常。”+args);
}
下面是我的ActiveX包装器类
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace AXImageAcquisition
{
#region ActiveX attributes
[ProgId("AXImageAcquisition.AXTwain_01")]
[Guid("d8ea830e-38b0-4f3b-8be4-39c417c27583")]
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
[ComSourceInterfaces(typeof(IComEvents))]
#endregion
public class AXTwain
{
#region Class Properties and Settings
private TwainMan scanner;
private String tempFileName;
public String TempFileName
{
get { return this.tempFileName; }
}
[ComVisible(false)]
public delegate void EventHandler(string args);
public event EventHandler DataPreparingFinished;
public bool imageScanned = false;
#endregion
#region Class Constructors
public AXTwain()
{}
#endregion
#region Class Methods
[ComVisible(true)]
public void AcquireImage()
{
this.DataPreparingFinished += new EventHandler(Delegate_DataPreparingFinished);
this.scanner = new TwainMan();
this.scanner.ImageScanned += new ImageScannedEventHandler(Scanner_ImageScanned);
TriggerJSCallback(); // HERE IN THE MAIN CODE FLOW THE MESSAGE GETS TO JS!!!
}
/// <summary>
/// Delegate that defines functionality for the ImageScanned event, defined in TwainMan class.
/// </summary>
/// <param name="Sender"></param>
/// <param name="e"></param>
public void Scanner_ImageScanned(object Sender, ImageScannedEventArgs e)
{
this.tempFileName = scanner.ToTempFile(e.Image);
Upload(this.tempFileName);
TriggerJSCallback(); // HERE (NOT IN THE MAIN CODE FLOW) THE MESSAGE NEVER GETS TO JS!!! WHYYYY? :(
}
/// <summary>
/// TODO!!!
/// </summary>
/// <param name="tempFileName"></param>
private void Upload(string tempFileName)
{
// TODO
}
/// <summary>
/// Test method for the DataPreparingFinished trigger.
/// </summary>
public void TriggerJSCallback()
{
EventHandler DataPreparingFinished = this.DataPreparingFinished;
if (null != DataPreparingFinished) DataPreparingFinished(this.tempFileName);
}
/// <summary>
/// Delegate that defines functionality for the DataPreparingFinished event, which is defined in IComEvents.
/// </summary>
/// <param name="msg">Arguments passing from C# to JS.</param>
void Delegate_DataPreparingFinished(string msg)
{
// MessageBox.Show("Delegate_DataPreparingFinished message! (C# code).\n Input message: " + msg);
}
#endregion
}
}
使用系统;
使用System.Collections.Generic;
使用系统文本;
使用System.Runtime.InteropServices;
名称空间获取
{
#区域ActiveX属性
[ProgId(“AXImageAcquisition.AXTwain_01”)]
[Guid(“d8ea830e-38b0-4f3b-8be4-39c417c27583”)]
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
[ComSourceInterfaces(类型(IComeEvents))]
#端区
公共类AXTwain
{
#区域类属性和设置
私人吐温曼扫描仪;
私有字符串文件名;
公共字符串临时文件名
{
获取{返回this.tempFileName;}
}
[ComVisible(false)]
公共委托void EventHandler(字符串参数);
公共事件事件处理程序DataPreparingFinished;
公共bool imageScanned=假;
#端区
#区域类构造函数
公共AXTwain()
{}
#端区
#区域类方法
[ComVisible(true)]
公共图像()
{
this.DataPreparingFinished+=新事件处理程序(委托\u DataPreparingFinished);
this.scanner=new TwainMan();
this.scanner.ImageScanned+=新ImageScannedEventHandler(scanner\u ImageScanned);
TriggerJSCallback();//在主代码流中,消息到达JS!!!
}
///
///为Twinman类中定义的ImageScanned事件定义功能的委托。
///
///
///
公共无效扫描仪\u ImageScanned(对象发送器,ImageScannedEventArgs e)
{
this.tempFileName=scanner.ToTempFile(e.Image);
上载(此.tempFileName);
TriggerJSCallback();//此处(不在主代码流中)消息永远不会到达JS!!!WHYYYY?:(
}
///
///待办事项!!!
///
///
私有无效上载(字符串tempFileName)
{
//待办事项
}
///
///数据准备完成触发器的试验方法。
///
public void TriggerJSCallback()
{
EventHandler DataPreparingFinished=this.DataPreparingFinished;
如果(null!=DataPreparingFinished)DataPreparingFinished(this.tempFileName);
}
///
///委托,用于定义在IComeEvents中定义的DataPreparingFinished事件的功能。
///
///从C#传递到JS的参数。
无效委托\u数据准备完成(字符串消息)
{
//MessageBox.Show(“委托数据准备完成的消息!(C代码)。\n输入消息:“+msg”);
}
#端区
}
}
如果你需要更多的代码,我也可以复制/粘贴代码的其余部分,即TWEMAN类和它的依赖关系。然而,所有这些都是从一个代码项目教程中提取的。BTW,感谢作者。
很难确定,因为我不从C语言写ActiveX组件,但是在C++中,这样的回调会有这样的效果。如果从主线程以外的线程调用。ActiveX通常希望所有调用都发生在主线程上。不过,也有一些方法可以让其他线程使用ActiveX,而且C#可能会自动为您执行此操作,因此在C#中这可能并不总是准确的
我建议您找到一种在主线程上触发函数的方法;我知道在Silverlight中使用Dispatcher可以实现这一点;也许您可以找到类似的方法?无论如何,这就是我要尝试的。Taxilian,衷心感谢您的回复。
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace AXImageAcquisition
{
#region ActiveX attributes
[ProgId("AXImageAcquisition.AXTwain_01")]
[Guid("d8ea830e-38b0-4f3b-8be4-39c417c27583")]
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
[ComSourceInterfaces(typeof(IComEvents))]
#endregion
public class AXTwain
{
#region Class Properties and Settings
private TwainMan scanner;
private String tempFileName;
public String TempFileName
{
get { return this.tempFileName; }
}
[ComVisible(false)]
public delegate void EventHandler(string args);
public event EventHandler DataPreparingFinished;
public bool imageScanned = false;
#endregion
#region Class Constructors
public AXTwain()
{}
#endregion
#region Class Methods
[ComVisible(true)]
public void AcquireImage()
{
this.DataPreparingFinished += new EventHandler(Delegate_DataPreparingFinished);
this.scanner = new TwainMan();
this.scanner.ImageScanned += new ImageScannedEventHandler(Scanner_ImageScanned);
TriggerJSCallback(); // HERE IN THE MAIN CODE FLOW THE MESSAGE GETS TO JS!!!
}
/// <summary>
/// Delegate that defines functionality for the ImageScanned event, defined in TwainMan class.
/// </summary>
/// <param name="Sender"></param>
/// <param name="e"></param>
public void Scanner_ImageScanned(object Sender, ImageScannedEventArgs e)
{
this.tempFileName = scanner.ToTempFile(e.Image);
Upload(this.tempFileName);
TriggerJSCallback(); // HERE (NOT IN THE MAIN CODE FLOW) THE MESSAGE NEVER GETS TO JS!!! WHYYYY? :(
}
/// <summary>
/// TODO!!!
/// </summary>
/// <param name="tempFileName"></param>
private void Upload(string tempFileName)
{
// TODO
}
/// <summary>
/// Test method for the DataPreparingFinished trigger.
/// </summary>
public void TriggerJSCallback()
{
EventHandler DataPreparingFinished = this.DataPreparingFinished;
if (null != DataPreparingFinished) DataPreparingFinished(this.tempFileName);
}
/// <summary>
/// Delegate that defines functionality for the DataPreparingFinished event, which is defined in IComEvents.
/// </summary>
/// <param name="msg">Arguments passing from C# to JS.</param>
void Delegate_DataPreparingFinished(string msg)
{
// MessageBox.Show("Delegate_DataPreparingFinished message! (C# code).\n Input message: " + msg);
}
#endregion
}
}