I showed my daughter how to write secret messages using ROT13.
If you haven't heard of ROT 13, imagine cutting an empty toilet roll in half
(vertically, so you still get 2 cylinders).
You write: ABCDEFGHIJKLMNOPQRSTUVWXYZ on one.
Then: ABCDEFGHIJKLMNOPQRSTUVWXYZ on the other.
Line up A on the top one with A on the bottom one.
ROT is short for rotate.
Now rotate the bottom cylinder 13 letters ahead so that A is above and N is below.
Flat on paper this now looks like:
ABCDEFGHIJKLMNOPQRSTUVWXYZ.
NOPQRSTUVWXYZABCDEFGHIJKLM.
You can now us this to encode and decode messages.
HELLO would become:
URYYB
http://en.wikipedia.org/wiki/Rot13
I also showed her letters to numbers:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26.
So here HELLO would become:
8 5 12 12 15.
Next I'll teach her that computers have character maps. ASCII.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.
65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90.
Hold down ALT and press 72 and you get H.
ALT 72 ALT 69 ALT 76 ALT 76 ALT 79 would become:
HELLO
Eventually I'll explain binary and how data is stored using electrical ons and offs.
public static void gridViewShowHeader(GridView gridView)
{
// Show header row (if none)
Table table = new Table();
if (gridView.Controls.Count != 0) table = (Table)gridView.Controls[0];
if (table.Rows.Count != 0 && ((GridViewRow)table.Rows[0]).RowType
== DataControlRowType.Header) return;
GridViewRow headerRow = new GridViewRow(-1, -1,
DataControlRowType.Header, DataControlRowState.Normal);
for (int i = 0; i < gridView.Columns.Count; i++)
{
TableHeaderCell headerCell = new TableHeaderCell();
headerCell.Text = gridView.Columns[i].HeaderText;
headerRow.Controls.Add(headerCell);
}
table.Rows.AddAt(0, headerRow);
gridView.Controls.Add(table);
}
To apply a DataFormatString on a BoundField like DataFormatString="{0:MM/dd/yyyy}
in older versions of .NET you need to set HtmlEncode="false". It doesn't seem to
be needed in 3.5. If you are going to allow editing also add
ApplyFormatInEditMode="true".
I decided to do this programmaticly because I am dealing with many reports (~8)
with lots of fields (28-53) that change often. There is one method for gridViews
and another for detailsView.
public static void gridViewFormatDates(GridView gv)
{
for (int i = 0; i < gv.Columns.Count; i++)
{
if (gv.Columns[i].GetType() == typeof(BoundField))
{
BoundField d = (BoundField)gv.Columns[i];
SqlDataSource sds = (SqlDataSource) gv.DataSourceObject;
if (gv.Columns[i].SortExpression.Contains("date"))
{
d.ApplyFormatInEditMode = true;
d.DataFormatString = "{0:MM/dd/yyyy}";
}
}
}
}
public static void detailsViewFormatDates(DetailsView dv)
{
for (int i = 0; i < dv.Fields.Count; i++)
{
if (dv.Fields[i].GetType() == typeof(BoundField))
{
BoundField d = (BoundField)dv.Fields[i];
if (dv.Fields[i].SortExpression.Contains("date"))
{
d.ApplyFormatInEditMode = true;
d.DataFormatString = "{0:MM/dd/yyyy}";
}
}
}
}
Ok you may have noticed that the fieldname (sortExpression) must have "date"
in it for this to work. Yeah it's ugly. So I came up with another solution
which still isn't perfect either.
I previously created a method to shorten long gridview columns. So I added
this automatic date formatting to it. Call this from your onrowcreated method
like gridViewShortenColumns(myGridView, e.Row, 30);
public static void gridViewShortenColumns(GridView gv, GridViewRow gvr, int width)
{
DataRowView dr = (DataRowView)gvr.DataItem;
for (int i = 0; i < gvr.Cells.Count; i++)
{
DataControlFieldCell d = (DataControlFieldCell)gvr.Cells[i];
String name = d.ContainingField.SortExpression;
if (!name.Equals("") && dr[name].GetType() == typeof(DateTime))
((BoundField)gv.Columns[i]).DataFormatString = "{0:MM/dd/yyyy}";
if (dr != null && name != null && !name.Equals("") &&
gvr != null && dr[name] != null && dr[name].ToString().Length > width)
{
gvr.Cells[i].ToolTip = dr[name].ToString();
dr[name] = dr[name].ToString().Substring(0, width) + " ...";
}
}
}
<html>
<head>
<title>Javascript examples</title>
<style>
.c1 {} .c2{} .c3 {} .c4{} .c5 {} .c6{} .c7 {} .c8{} .c9 {} .c10{}
.LockOff { display: none; visibility: hidden; }
.LockOn
{
display: block;
visibility: visible;
position: absolute;
z-index: 998;
top: 0px;
left: 0px;
width: 105%;
height: 105%;
font-size: 4em;
background-color: #ccc;
text-align: center;
padding-top: 20%;
padding-bottom: 40%;
filter: alpha(opacity=55);
opacity: 0.55;
}
</style>
<script>
var previousRow;
var previousRowColor;
function highlightRow(row, newColor)
{
if(previousRow != null) previousRow.style.backgroundColor = previousRowColor;
if(previousRow != row)
{
previousRow = row;
previousRowColor = row.style.backgroundColor;
row.style.backgroundColor = newColor;
}
else previousRow = null;
}
function getRadioValue(radioObj)
{
if (!radioObj) return "";
if(radioObj.checked) return radioObj.value;
for (var i = 0; i < radioObj.length; i++) { if (radioObj[i].checked) return radioObj[i].value; }
return "";
}
function hideClass(className)
{
for(i=0; i<document.styleSheets.length; i++)
{
rules = document.styleSheets[i].rules;
if(rules == null) rules = document.styleSheets[i].cssRules;
for(j=0; j<rules.length; j++)
{
if(rules[j].selectorText == '.'+className) rules[j].style.display='none';
}
}
}
function w()
{
var lock = document.getElementById('pleaseWaitPane');
if(lock) lock.className = 'LockOn';
}
function no_w()
{
var lock = document.getElementById('pleaseWaitPane');
if(lock) lock.className = 'LockOff';
}
</script>
</head>
<body>
<h2>Here are examples of 4 useful javascript functions</h2>
<div id="pleaseWaitPane" class="LockOff">
Please Wait
<button onclick="no_w(); document.execCommand('stop');">Cancel</button>
</div>
<a href="https://webapp1.tamc.amedd.army.mil/phonelist/slowLoading.jsp" onclick="w();">Wait example link</a>
<form method="get" action="https://webapp1.tamc.amedd.army.mil/phonelist/slowLoading.jsp" onsubmit="w();">
<input type="submit" value="Wait example form"/>
</form>
<input type="radio" name="radio1" value="value1"/>value1
<input type="radio" name="radio1" value="value2"/>value2
<input type="radio" name="radio1" value="value3"/>value3
<input type="radio" name="radio1" value="value4"/>value4
<button onclick="var str=getRadioValue(radio1); if(str == '') alert('Please choose a value'); else alert('You choose '+str); ">
getRadioValue example
</button><br/><br/>
<b>HideColumn example</b>: click an x to temporarily hide a column.<br/>
<b>HighlightRow example</b>: click a row to see it highlighted.<br/>
<table border="1">
<tr>
<th class="c1">col1 <a href="#" onclick="hideClass('c1');">x</a></th>
<th class="c2">col2 <a href="#" onclick="hideClass('c2');">x</a></th>
<th class="c3">col3 <a href="#" onclick="hideClass('c3');">x</a></th>
<th class="c4">col4 <a href="#" onclick="hideClass('c4');">x</a></th>
<th class="c5">col5 <a href="#" onclick="hideClass('c5');">x</a></th>
<th class="c6">col6 <a href="#" onclick="hideClass('c6');">x</a></th>
</tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
<tr onclick="highlightRow(this,'pink');"><td class="c1">test1</td><td class="c2">test2</td><td class="c3">test3</td><td class="c4">test4</td><td class="c5">test5</td><td class="c6">test6</td></tr>
</table>
</body>
</html>
asp:DropDownList departmentDD has 0 elements.
In the code-behind I set departmentDD.SelectedIndex = 9;
In the debugger I see that departmentDD.SelectedIndex stays at 0.
I would expect it to throw an error, stay at zero, or switch to 9.
It stayed at 0. I'm ok with that.
Further down in the codebehind I do push some data into
departmentDD and departmentDD.databind.
Suddently departmentDD.SelectedIndex is equal to 9!
It remembered and set the value later once it could do it.
That's nice of it. I don't expect or want to object to be nice.
I want it to be consistant and predictable.
How many other weird quirks are in the web component objects?
So I ran another test.
asp:DropDownList departmentDD has 2 elements.
In the code-behind I set departmentDD.SelectedIndex = 1;
In the debugger I see that departmentDD.SelectedIndex is now 1.
I don't like this.
If it's going to some lame late update of selectedIndex when databound,
it should do it that way everytime.
There are no conditional tags in .NET web components.
So instead of a nice jstl tag in java like:
Java/JSP/JSTL/EL Solution #1:
<c:if test="${row.name == ''}"%gt;BLANK%lt;/c:if>
In .NET I would have to create a code-behind wrapper method like:
Solution #2:
protected String testEmpty(String stringToCheck, String trueReturn, String falseReturn)
{
if("".Equals(stringToCheck)) return(trueReturn);
else return(falseReturn);
}
Then use this in the form view:
<%# testEmpty(DataBinder.Eval(Container.DataItem, "name"),
"BLANK", DataBinder.Eval(Container.DataItem, "name")) %>
Or Solution #3:
protected void OnRowCreated(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DataRowView dataRow = e.Row.DataItem as DataRowView;
Object dataValue = dataRow["name"];
if("".Equals(dataValue)) e.Row.Cells[2].Text = "BLANK";
}
}
In solution 2 I am essentially creating my own conditional tag. Why shouldn't there be one like this by default? In solution 3 I am creating codebehind that will break if I reorder the fields in the formview.
Make sure you don't use # signs in html comments. Master Pages choke on those. Example: <!-- #BeginEditable "sidebar" -->
http://www.vbforums.com/showthread.php?t=547336
