使用Anthem.NET 1.5中的FileUpload控件实现Ajax方式的文件上传

Anthem.NET（我的介绍和比较，还有一篇）刚刚发布了其最新的1.5版本，其中很不错的一个新功能就是对文件上传功能的Ajax实现。本文将简要介绍一下该功能的使用方法。

 

Anthem.NET的下载与安装

Anthem.NET可以在此下载：http://sourceforge.net/project/showfiles.php?group_id=151897&package_id=168043&release_id=493609

下载之后解压缩至硬盘中的某一目录中，编译项目得到Anthem.dll。然后将其拷贝到Web站点的bin目录下：

打开Web站点的Web.config文件，在configuration>\ <system.web>\ <pages>\ <controls>中添加如下一行，注册Anthem.NET控件：

<add tagPrefix="anthem" namespace="Anthem" assembly="Anthem"/>

Anthem.NET提供了一套自己就带有Ajax功能的、继承于现有ASP.NET控件的服务器端控件。根据上面在web.config文件中的注册，这部分控件的前缀为anthem。

Anthem.NET支持ASP.NET 1.1和ASP.NET 2.0，不过本文的示例程序均基于ASP.NET 2.0。

 

普通的ASP.NET文件上传

先看一下普通的ASP.NET文件上传功能的实现，代码如下：

<asp:FileUpload ID="defaultFileUpload" runat="server" />
<asp:Button ID="defaultUploadButton" runat="server"
  OnClick="defaultUploadButton_Click" Text="Upload" />
<asp:Label ID="defaultResultLabel" runat="server" Text=""></asp:Label>

后台代码，只是简单地将文件名和文件大小显示出来：

protected void defaultUploadButton_Click(object sender, EventArgs e)
{
    defaultResultLabel.Text = string.Format("File \"{0}\" uploaded ({1} bytes).",
        defaultFileUpload.FileName,
        defaultFileUpload.FileBytes.Length
    );
}

 

Anthem.NET的Ajax文件上传

Anthem.NET中的Ajax文件上传功能靠的是其自己的FileUpload控件，其实使用起来和普通的ASP.NET FileUpload控件差不多，下面是HTML部分的代码：

<anthem:FileUpload ID="anthemFileUpload" runat="server" />
<anthem:Button ID="anthemUploadButton" TextDuringCallBack="uploading..." EnabledDuringCallBack="false"
    runat="server" Text="Upload" OnClick="anthemUploadButton_Click" />
<anthem:Label ID="anthemResultLabel" runat="server" Text=""></anthem:Label>

注意控件的前缀都是anthem。那个Button的TextDuringCallBack属性设置了异步回送时按钮中的文本；EnabledDuringCallBack属性让该按钮在进行异步回送时禁用，免得用户等得不耐烦。

后台代码同样是将文件名和文件大小显示出来，不过注意这一句anthemResultLabel.UpdateAfterCallBack = true;，用来在回调之后更新anthemResultLabel上的文字：

protected void anthemUploadButton_Click(object sender, EventArgs e)
{
    anthemResultLabel.Text = string.Format("File \"{0}\" uploaded ({1} bytes).",
        anthemFileUpload.FileName,
        anthemFileUpload.FileBytes.Length
    );
    anthemResultLabel.UpdateAfterCallBack = true;
}

 

示例程序演示

示例程序的界面如下，上面部分是普通的ASP.NET文件上传，下面是Anthem.NET的Ajax文件上传：

使用普通的ASP.NET文件上传，可以看到页面有一次闪烁，不过上传功能没什么问题：

而使用下面部分的Anthem.NET的Ajax文件上传，可以看到上传时的界面（按钮禁用，文本变化）：

上传完成之后，没有页面闪烁：

打开Fiddler看看HTTP请求，上面的是传统上传，下面是Ajax的，差别显而易见……

 

代码下载

本文提到的完整的示例程序代码：https://files.cnblogs.com/dflying/AnthemNETFileUploadDemo.zip

 

更多参考资料

Anthem.NET官方网站：http://sourceforge.net/projects/anthem-dot-net/

Anthem.NET在线文档：http://anthem-dot-net.sourceforge.net/docs/

Anthem.NET在线示例程序：http://anthem.talloaksoftware.com/Default.aspx

Fiddler官方网站：http://www.fiddlertool.com/

 

to jeff（实现方式）

除了用IFrame，还有什么好办法么？它也是用的IFrame，相关代码如下：注意58-61,109-113,131-148这几段（粗体部分）。

有空的时候改到Atlas里面吧，呵呵，造福群众阿

function Anthem_CallBack(url, target, id, method, args, clientCallBack, clientCallBackArg, includeControlValuesWithCallBack, updatePageAfterCallBack) {
    if (typeof(window.Anthem_PreCallBack) == "function") {
        var preCallBackResult = Anthem_PreCallBack();
        if (!(typeof preCallBackResult == "undefined" || preCallBackResult)) {
            if (typeof(window.Anthem_CallBackCancelled) == "function") {
                Anthem_CallBackCancelled();
            }
            return null;
        }
    }
    var encodedData = "";
    if (target == "Page") {
        encodedData += "&Anthem_PageMethod=" + method;
    } else if (target == "MasterPage") {
        encodedData += "&Anthem_MasterPageMethod=" + method;
    } else if (target == "Control") {
        encodedData += "&Anthem_ControlID=" + id.split(":").join("_");
        encodedData += "&Anthem_ControlMethod=" + method;
    }
    if (args) {
        for (var argsIndex = 0; argsIndex < args.length; ++argsIndex) {
            if (args[argsIndex] instanceof Array) {
                for (var i = 0; i < args[argsIndex].length; ++i) {
                    encodedData += "&Anthem_CallBackArgument" + argsIndex + "=" + Anthem_Encode(args[argsIndex][i]);
                }
            } else {
                encodedData += "&Anthem_CallBackArgument" + argsIndex + "=" + Anthem_Encode(args[argsIndex]);
            }
        }
    }

    if (updatePageAfterCallBack) {
        encodedData += "&Anthem_UpdatePage=true";
    }

    // Anthem will normally use an XmlHttpRequest to communicate with the server.
    // But if an Anthem.FileUpload control is discovered on the page, then Anthem
    // will use a hidden IFRAME instead. This hidden IFRAME is often called an IOFrame
    // by AJAX library authors, so that is the name we use here.
    var useIOFrame = false;

    // Scan the controls on the form and extract their values.
    if (includeControlValuesWithCallBack) {
        var form = Anthem_GetForm();
        if (form != null) {
            for (var elementIndex = 0; elementIndex < form.length; ++elementIndex) {
                var element = form.elements[elementIndex];
                if (element.name) {
                    var elementValue = null;
                    if (element.nodeName.toUpperCase() == "INPUT") {
                        var inputType = element.getAttribute("type").toUpperCase();
                        if (inputType == "TEXT" || inputType == "PASSWORD" || inputType == "HIDDEN") {
                            elementValue = element.value;
                        } else if (inputType == "CHECKBOX" || inputType == "RADIO") {
                            if (element.checked) {
                                elementValue = element.value;
                            }
                        } else if (inputType == "FILE") {
                            // If the FILE element has a value (the path to the file), then an
                            // IOFrame will be used to handle the callback.
                            useIOFrame = useIOFrame | !(element.value == null || element.value.length == 0);
                        }
                    } else if (element.nodeName.toUpperCase() == "SELECT") {
                        if (element.multiple) {
                            elementValue = [];
                            for (var i = 0; i < element.length; ++i) {
                                if (element.options[i].selected) {
                                    elementValue.push(element.options[i].value);
                                }
                            }
                        } else if (element.length == 0) {
                            elementValue = null;
                        } else {
                            elementValue = element.value;
                        }
                    } else if (element.nodeName.toUpperCase() == "TEXTAREA") {
                        elementValue = element.value;
                    }
                    if (elementValue instanceof Array) {
                        for (var i = 0; i < elementValue.length; ++i) {
                            encodedData += "&" + element.name + "=" + Anthem_Encode(elementValue[i]);
                        }
                    } else if (elementValue != null) {
                        encodedData += "&" + element.name + "=" + Anthem_Encode(elementValue);
                    }
                }
            }
            // ASP.NET 1.1 won't fire any events if neither of the following
            // two parameters are not in the request so make sure they're
            // always in the request.
            if (typeof form.__VIEWSTATE == "undefined") {
                encodedData += "&__VIEWSTATE=";
            }
            if (typeof form.__EVENTTARGET == "undefined") {
                encodedData += "&__EVENTTARGET=";
            }
        }
    }

    if (encodedData.length > 0) {
        encodedData = encodedData.substring(1);
    }
    if (typeof(Anthem_DebugRequestText) == "function") {
        Anthem_DebugRequestText(encodedData.split("&").join("\n&"));
    }

    // Send the callback request to the server. Use an IOFrame if there is a file upload,
    // otherwise use an XmlHttpRequest.
    if (useIOFrame) {
        // To allow multiple requests at the same time, all of the Anthem parameters are
        // passed to the server via the querystring
        var action = Anthem_GetCallBackUrl();
        action = action + "&Anthem_IOFrame=true";
        if (updatePageAfterCallBack) {
            action = action + "&Anthem_UpdatePage=true";
        }

        // We could generate an anonymous function on the fly to handle the clientCallBack
        // and assign that to the iframe onload event (in fact this is how XmlHttpRequests are
        // handled). But that makes it very hard to debug the callback response. Instead
        // we will stuff the clientCallBack function and args into an array and then hard code
        // the onload event handler. The handler will find the appropriate callback info in
        // the array and handle the clientCallBack.
        var id = "f" + new String(Math.floor(9999 * Math.random())); // Generate frame number
        if (typeof(clientCallBack) == "function") {
            var frame = { "id":id, "clientCallBack":clientCallBack, "clientCallBackArg":clientCallBackArg };
            callbackFrames.push(frame);
        }

        // Create a new, invisible iframe to handle the io.
        var ioframe = null;
        if (window.ActiveXObject) {
            ioframe = document.createElement("<iframe name=\"" + id + "\" id=\"" + id + "\" onload=\"Anthem_HandleIOFrameResponse('" + id + "');\"/>");
        } else {
            ioframe = document.createElement("iframe");
            ioframe.id = id;
            ioframe.name = id;
            ioframe.onload = function (){ Anthem_HandleIOFrameResponse(id); }
        }
        ioframe.style.visibility = "hidden";
        ioframe.style.height = "1px";
        document.body.appendChild(ioframe);

        // Submit this form in the hidden iframe
        var theForm = Anthem_GetForm();
        var tempActionUri = theForm.action;
        theForm.action = action;
        theForm.target = id;
        try {
            theForm.submit();
        } catch (e) {
            result = { "value": null, "error": e.message };
            if (typeof(Anthem_DebugError) == "function") {
                Anthem_DebugError(e.name + ": " + e.message + " (" + e.number + ")");
            }
            if (typeof(window.Anthem_Error) == "function") {
                Anthem_Error(result);
            }
        }

        // Restore the form
        theForm.target = "";
        theForm.action = tempActionUri;

    } else {

        var x = Anthem_GetXMLHttpRequest();
        var result = null;
        if (!x) {
            result = { "value": null, "error": "NOXMLHTTP" };
            if (typeof(Anthem_DebugError) == "function") {
                Anthem_DebugError(result.error);
            }
            if (typeof(window.Anthem_Error) == "function") {
                Anthem_Error(result);
            }
            if (typeof(clientCallBack) == "function") {
                clientCallBack(result, clientCallBackArg);
            }
            return result;
        }
        var action = Anthem_GetCallBackUrl();
        x.open("POST", url ? url : action, clientCallBack ? true : false);
        x.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
        x.setRequestHeader("Accept-Encoding", "gzip, deflate");
        if (typeof(clientCallBack) == "function") {
            x.onreadystatechange = function() {
                if (x.readyState != 4) {
                    return;
                }
                if (typeof(Anthem_DebugResponseText) == "function") {
                    Anthem_DebugResponseText(x.responseText);
                }
                result = Anthem_GetResult(x);
                if (result.error) {
                    if (typeof(Anthem_DebugError) == "function") {
                        Anthem_DebugError(result.error);
                    }
                    if (typeof(window.Anthem_Error) == "function") {
                        Anthem_Error(result);
                    }
                }
                if (updatePageAfterCallBack) {
                    Anthem_UpdatePage(result);
                }
                Anthem_EvalClientSideScript(result);
                clientCallBack(result, clientCallBackArg);
                x = null;
                if (typeof(window.Anthem_PostCallBack) == "function") {
                    Anthem_PostCallBack();
                }
            }
        }
        x.send(encodedData);
        if (typeof(clientCallBack) != "function") {
            if (typeof(Anthem_DebugResponseText) == "function") {
                Anthem_DebugResponseText(x.responseText);
            }
            result = Anthem_GetResult(x);
            if (result.error) {
                if (typeof(Anthem_DebugError) == "function") {
                    Anthem_DebugError(result.error);
                }
                if (typeof(window.Anthem_Error) == "function") {
                    Anthem_Error(result);
                }
            }
            if (updatePageAfterCallBack) {
                Anthem_UpdatePage(result);
            }
            Anthem_EvalClientSideScript(result);
            if (typeof(window.Anthem_PostCallBack) == "function") {
                Anthem_PostCallBack();
            }
        }
    }
    return result;
}