asp.net javascript消息未显示

Question

I have a button and onclick is set to this method which should display a simple JS alert pop up window: 我有一个按钮，并将onclick设置为此方法，该方法应该显示一个简单的JS警报弹出窗口：

string message = "File is already open. <br>Please close the file and try again.";
    System.Text.StringBuilder sb = new System.Text.StringBuilder();
    sb.Append("<script type = 'text/javascript'>");
    sb.Append("window.onload=function(){");
    sb.Append("alert('");
    sb.Append(message);
    sb.Append("')};");
    sb.Append("</script>");
    ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", sb.ToString());

I have used the code above before and it has worked but not this time. 我以前使用过上面的代码，但它确实有效，但是这次没有。 The only difference is that I was using master pages for the other site and not for this one, and this one also has a timer going. 唯一的区别是，我在另一站点而不是本站点使用母版页，并且该页还有一个计时器。

Is there anything JS related to load in the <head> of the aspx page? 在aspx页面的<head>中是否有与加载有关的JS？

protected void btnToCSV_Click(object sender, EventArgs e)
    {
        try
        {
            StreamWriter writer = new StreamWriter(@"\\server location\test.csv");

            Some writer.write stuff...

            writer.Close();
        }
        catch (Exception ex)
        {
            lblMessage.Visible = true;
            string message = "File is already open. Please close the file and try again.";
            ClientScript.RegisterClientScriptBlock(
               this.GetType(),
              "alert",
              string.Format("alert('{0}');", message),
              true);

        }
}

Answer 1

Try with this simplyfied version 尝试使用此简单版本

string message = "File is already open. <br>Please close the file and try again.";
ScriptManager.RegisterClientScriptBlock(
  UpdatePanel1, // replace UpdatePanel1 by your UpdatePanel id
  UpdatePanel1.GetType(), // replace UpdatePanel1 by your UpdatePanel id
  "alert", 
  string.Format("alert('{0}');",message), 
  true );

Answer 2

You are not encoding anything here: 您在此处未进行任何编码：

sb.Append(message);

If the message is Hello Jean d'Arc (notice the single quote) you will end up with the following code: 如果消息是Hello Jean d'Arc （请注意单引号），您将得到以下代码：

alert('Hello Jean d'Arc');

I am leaving you imagine the result of this => a javascript error of course. 我让您想象这=>当然是javascript错误的结果。

To fix this error make sure that you have properly encoded the argument. 要解决此错误，请确保已正确编码了参数。 One way to do this is to JSON serialize it: 一种方法是JSON序列化它：

var serializer = new JavaScriptSerializer();
sb.AppendFormat("alert({0});", serializer.Serialize(message));

Also since you have already includeed the <script> tags, make sure that you pass false as last argument of the RegisterClientScriptBlock function to avoid adding them twice: 同样，由于已经包含了<script>标记，因此请确保将false传递为RegisterClientScriptBlock函数的最后一个参数，以避免将它们添加两次：

ClientScript.RegisterClientScriptBlock(
    this.GetType(), 
    "alert", 
    sb.ToString(), 
    false           // <!---- HERE
);

And here's how the full code might look like: 完整的代码如下所示：

var message = "File is already open. <br>Please close the file and try again.";
var sb = new StringBuilder();
sb.Append("<script type=\"text/javascript\">");
sb.Append("window.onload=function() {");
var serializer = new JavaScriptSerializer();
sb.AppendFormat("alert({0});", serializer.Serialize(message));
sb.Append("};");
sb.Append("</script>");
ClientScript.RegisterClientScriptBlock(
    this.GetType(), 
    "alert", 
    sb.ToString(), 
    false
);

Another remark is that if you are doing this in an AJAX call you should use the ClientScript.RegisterStartupScript method. 另一个要点是，如果在AJAX调用中执行此操作，则应使用ClientScript.RegisterStartupScript方法。

asp.net javascript消息未显示

问题描述

2 个解决方案

解决方案1
3 已采纳 2012-06-29 17:40:18

解决方案2
2 2012-06-29 17:39:47

asp.net javascript消息未显示

问题描述

2 个解决方案

解决方案1 3 已采纳 2012-06-29 17:40:18

解决方案2 2 2012-06-29 17:39:47

解决方案1
3 已采纳 2012-06-29 17:40:18

解决方案2
2 2012-06-29 17:39:47