Application Development Cloud – Page 7 – Everything I need for multimedia production and application development anywhere on any device

Checking boxes in a C# ASP checkbox list using values from a database

Suppose you have an ASP checkbox list and you need to check the boxes using data returned from the information storage.

You have a couple of ways the data could have been stored. If each checkbox option is a separate field in the database, you could go with a simple loop, but if they have been stored in one field, you need to put some programming power into it.

Here’s a scenario. I have a “seasons” checklist. There are values stored in the db that the user selected. For example if they chose Summer and Fall, the db string “seasons” would contain “Summer Fall”.

<asp:CheckBoxList ID="CheckBoxListSeasons" runat="server">
 <asp:ListItem>Summer</asp:ListItem>
 <asp:ListItem>Fall</asp:ListItem>
 <asp:ListItem>Winter</asp:ListItem>
 <asp:ListItem>Spring</asp:ListItem>
 </asp:CheckBoxList>

In order to display the list with the Summer and Fall boxes checked, I would do this:

string seasons = "Summer Fall"
for (int i = 0; i < CheckBoxListSeasons.Items.Count; i++)
 {

if (seasons.Contains(CheckBoxListSeasons.Items[i].Value))
 {

CheckBoxListSeasons.Items[i].Selected = true;
 }
 } // end checkbox loop

Password Auditing

There are ways to “audit” passwords.

http://www.techrepublic.com/article/audit-passwords-with-a-password-cracking-tool/

Here is a tool to retrieve passwords from chrome

http://securityxploded.com/chrome-password-dump.php

Video encoding and streaming

Azure offers encoding and live or on-demand streaming in the cloud.

https://azure.microsoft.com/en-us/services/media-services/encoding

Transformation Matrices

Rotate a figure 180 degrees around the origin:

From your original figure, just reverse the polarity of the ordered pairs.

Point A(x,y) will be Point a(-x, -y)

(-6,3) (-3,3) (-2,5) (-2,1) (-6,1) original
(6,-3) (3,-3) (2,-5) (2,-1) (6,-1) rotated 180 degrees around origin.

Reflect over y-axis

From the original, reverse the polarity of the x value. Point A(x,y) will become point a(-x,y)

(-6,3) (-3,3) (-2,5) (-2,1) (-6,1) original
(6,3) (3,3) (2,5) (2,1) (6,1) reflected over y axis

Rotate 90 degrees counter clockwise around origin

The new position of point M (h, k) will become M’ (k, -h)

Online graph paper and graphing tools

https://www.desmos.com/calculator

Super sweet graph. Also an app for phone as well.

Use Web Config App Settings Variables .NET

In the web config configuration section, you can add app settings

<appSettings>
     <add key="MyVariable" value="MyValue" />
 </appSettings>

You can access these variables using this code:

string MyVariable= ConfigurationManager.AppSettings["MyVariable"];

SQL Select records by the hour or the half hour

Here is a handy SQL snippet to select records by the half hour in a certain date range.

SELECT DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0) as LoginHour, Count(*) as NumberOfUsers FROM[my_db].[dbo].[MyTable] WHERE [LoginTime] BETWEEN '{0} 00:00:00.00' AND '{0} 23:59:59.999' GROUP BY DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0) ORDER BY DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0)

The result set will look something like this:

Here is a code to select by the hour if you don’t need to go down to the half hour

SELECT datepart(HH, [LoginTime]) as LoginHour, Count(*) as NumberOfUsers

FROM[my_db].[dbo].[MyTable]

WHERE[LoginTime] BETWEEN '09/07/2017 00:00:00.00' AND dateadd(dd, 1, '10/20/2017 23:59:59.999')

GROUP BY datepart(HH, [LoginTime])

ORDER BY datepart(HH, [LoginTime])

And the result set will resemble this:

Here is a snipped to get a all records regardless of the date, and count by the half hour.

SELECT substring(CONVERT(VARCHAR, DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0), 108),0,6) as LoginHour, Count(*) as NumberOfUsers FROM[my_db].[dbo].[MyTable]  GROUP BY substring(CONVERT(VARCHAR, DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0), 108),0,6) ORDER BY substring(CONVERT(VARCHAR, DATEADD(mi, DATEDIFF(mi,0,[LoginTime])/30*30,0), 108),0,6)

SVC Fitness Center Use Reports

I was tasked to visualize the data from years of students using the Fitness Center. I worked with C# and SQL server to make make charts from the data. I used Visual Studio to create a WebForms Application and deployed to IIS server. I was able to leverage active directory to provide integrated authentication to this resource.

Error checking with ASP classic VbScript

Here is a handy snippet for those rare occasions when you bother to error check.

If Err.Number <> 0 Then
subject = "Error creating early alert"
email_message = "There was the following error while creating an early alert record: " & Err.Number & " : " & Err.Description
sendEmail adminEmail, email_message, from_email, subject
End If

Can deliver a helpful error message such as:

There was the following error while creating a record: -2147217900 : Unclosed quotation mark after the character string ‘Failed a quiz/test’.

Prepend text “Select Value” to a databound dropdown list c#

You have a dropdown list, populated via sql data source, and you want it to have “Select a value” as the first selected option.

protected void DropDownList2_DataBound(object sender, EventArgs e)
        {
            DropDownList list = sender as DropDownList;
            if(list != null)
            {
                list.Items.Insert(0, "--Select Date--");
            }
        }