ASP NET parameter: time

Monday, March 26, 2012

pass value to image control

This is my first time to use asp.net. I just want to get an image name passed from url (by using request.querystring), and then display this image, when user click the image, I also display the mouse coordinate. But I just can not get it to work, please help. Thanks. The following is my code:


<script runat="server">
Sub getCoordinates(sender As Object, e As ImageClickEventArgs)
 mess.Text="Coordinates: " & e.x & ", " & e.y
End Sub
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 Dim imagename as String = Request.QueryString("name")
 Dim imagePath as String =Server.MapPath("/keller/portrait/" & imagename)
End Sub
</script>
<html>
<body>
<form runat="server">
<p>Click on the image:</p>
<asp:Image
runat="server"
ImageUrl="<%=iamgePath%>"
OnClick="getCoordinates"/>
<p><asp:label id="mess" runat="server"/></p>
</form>
</body>
</html>

Welcome to the ASP.NET Forums, lily1.

The following update to your code will correctly show the image passed in with the QueryString.

<%@. page language="VB" debug="true" %>
<html>
<head>
<title>This is main Page</title>
<script runat="server"
Sub getCoordinates(sender As Object, e As ImageClickEventArgs)
 mess.Text="Coordinates: " & e.x & ", " & e.y
End SubPrivate Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 Dim imagename as String = Request.QueryString("name")
 Dim imagePath As String = Server.MapPath("/keller/portrait/" & imagename & ".gif")
 MyImage.ImageUrl = imagePath
End Sub
</script>
<html>
<body>
 <form runat="server">
 <p>Click on the image:</p>
 <asp:Image runat="server"
 id="MyImage"
 OnClick="getCoordinates" />
 <p><asp:label id="mess" runat="server" /></p>
 </form>
</body>
</html>

The only difference is that I gave the asp:Image control an ID, and used this ID in your Page_Load code to set its ImageUrl property.

For details of how to get your imagemap working, see the following tutorial:
ImageMap.NET

I hope this helps.
Thanks for your help. I tried your script, The picture can be displayed correctly now, but when i click the picture, I got javascript error, it seems that function 'getCoordinates' does not execute at server instead it tries to run at client side. Here is url of the page:http://user1046822.wx15.registeredsite.com/keller/imagecrop_coodinates.aspx?name=test.jpg . Could you please tell me what is the problem? Thanks again.
> Could you please tell me what is the problem?

You've defined the problem yourself ... that getCoordinates tries to run at the client-side, not at the server.

Please go through the article I provided above. That will explain how to send click coordinates back to your server-side code.

Wednesday, March 21, 2012

Passing a string[] into a class

hi i am trying to pass a string array( all of the values at the same time) into a class

I am using this code trying to pass into this class

string[] itemTitle;string[] itemNames; OdbcConnection userCheckCon = sqlconnect.Connect(); OdbcCommand userCheck =new OdbcCommand("select Username from tbl_usr where Username = '" + uName +"'", userCheckCon); OdbcDataReader userRead = userCheck.ExecuteReader();int count = 0;while (userRead.Read()) {if (userRead.HasRows && variablePass) { itemTitle[count] ="userName"; itemNames[count] = uName; }else { itemTitle[count] ="userName"; itemNames[count] = ("<span class='greenHigh'>" + uName +" is available </span>"); } count++; } userRead.Close(); userCheckCon.Close();//END XML xmlGen userC =new xmlGen(); userC.xmlStart(writer); userC.addNode(writer,itemTitle[],itemNames[]); userC.xmlEnd(writer);

The problem is on the userC.addNode line and this is the class i am trying to pass into it

class

 public XmlTextWriter addNode(XmlTextWriter writer,string[] itemTitle,string[] itemName)
 {
 for(int items = 0; items < itemTitle.Length; items++)
 {
 writer.WriteElementString(itemTitle[items], itemName[items]);
 }
 return writer;
 }

Thanks

Dan

Two problems.

1. Your string[] itemTitle needs a = new string[MaxRows] where maxrows is an int. If you dont know the size until later in the code you can always use a List<string> instead.

2 (and more importantly), take out the []'s from userC.addNode(writer,itemTitle[],itemNames[]); Should be userC.addNode(writer,itemTitle,itemNames);

using arry of strings here is not recomended ,

because we dont know the number of elements ,

you must useStringCollection class ,

this is a dynamic array,

you can add and remove from it as you want ,

so change you variables types as follows :

StringCollection itemTitle=new StringCollection ();

StringCollection itemNames=new StringCollection ();

now to add items to these colletions use this :

itemTitle.add("your string") ....

and to iterate inside these collections use this :

for( int i=0; collection.count-1; i++)

{ yoou code here }

regards,

This code is also vulnerable to SQL injection.

Hi thanks will give this all a go tonight

and how is it vunerable to SQL injection

 OdbcCommand userCheck =new OdbcCommand("select Username from tbl_usr where Username = '" + uName +"'", userCheckCon);

if uName is like the query string or textbox text value all I need to enter to return the all rows isanything' OR 'x'='x

Or If I want to get more malicious I can do a ' delete from Users --

Look into stored procedures if you want to solve this problem.

Monday, March 26, 2012

pass value to image control

Wednesday, March 21, 2012

Passing a string[] into a class

ASP NET parameter

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