Tutorial by Examples: ha

Create a new httpHandler inside your ASP.NET project. Apply the following code (VB) to the handler file: Public Class AttachmentDownload Implements System.Web.IHttpHandler Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest ' pass an ID thr...

Const baseString As String = "Foo Bar" Dim leftText As String leftText = Left$(baseString, 3) 'leftText = "Foo"

Const baseString As String = "Foo Bar" Dim rightText As String rightText = Right$(baseString, 3) 'rightText = "Bar"

Const baseString As String = "Foo Bar" 'Get the string starting at character 2 and ending at character 6 Dim midText As String midText = Mid$(baseString, 2, 5) 'midText = "oo Ba"

The most flexible base R function for reshaping data is reshape. See ?reshape for its syntax. # create unbalanced longitudinal (panel) data set set.seed(1234) df <- data.frame(identifier=rep(1:5, each=3), location=rep(c("up", "down", "left", &quo...

Instructs the engine to use hash method to join tables in the argument. Usage : use_hash(TableA [TableB] ... [TableN]) As explained in many places, "in a HASH join, Oracle accesses one table (usually the smaller of the joined results) and builds a hash table on the join key in memory. It the...

Without Auto Layout, animation is accomplished changing a view's frame over time. With Auto Layout, the constraints dictate the view frame, so you have to animate the constraints instead. This indirection makes animation harder to visualize. Here are the ways to animate with Auto Layout: Change ...

SELECT * FROM customers WHERE id IN ( SELECT DISTINCT customer_id FROM orders ); The above will give you all the customers that have orders in the system.

Converting between encodings is easy with C++11 and most compilers are able to deal with it in a cross-platform manner through <codecvt> and <locale> headers. #include <iostream> #include <codecvt> #include <locale> #include <string> using namespace std; i...

When a user press F1 on a control or click on Help button of form (?) and then clicks on a control the HelpRequested event will be raised. You can handle this event to provide custom action when user requests help for controls or form. The HelpRequested supports bubble up mechanism. It fires for y...

If you have a Form with MinimizeBox and MaximizeBox set to true, then you can not show Help button on title-bar of Form and will lose the feature of click on help button to convert it to help cursor to be able to click on controls to show help. You can make a menu item on MenuStrip act like standar...

You can detect when a user Clicked on a HelpButton on title-bar of form by handling HelpButtonClicked. You can let the event continue or cancel it by setting Cancel property of its event args to true. private void Form1_HelpButtonClicked(object sender, CancelEventArgs e) { e.Cancel = true; ...

Default behavior when cloning an object is to perform a shallow copy of the object's fields. In that case, both the original object and the cloned object, hold references to the same objects. This example shows that behavior. import java.util.List; public class Sheep implements Cloneable { ...

Exceptions represent programmer-level bugs like trying to access an array element that doesn’t exist. Errors are user-level issues like trying load a file that doesn’t exist. Because errors are expected during the normal execution of a program. Example: NSArray *inventory = @[@"Sam"...

The contents of files and network messages may represent encoded characters. They often need to be converted to unicode for proper display. In Python 2, you may need to convert str data to Unicode characters. The default ('', "", etc.) is an ASCII string, with any values outside of ASCII ...

This will trigger the native email client for sharing text. Parameters : Email To address, Subject, Body. Code Sample : you can call the function wherever you need, (mostly inside click listeners) like below Calling function shareEmail("[email protected]", "Email sharing example&q...

VBA is compiled in run-time, which has a huge negative impact on it's performance, everything built-in will be faster, try to use them. As an example I'm comparing SUM and COUNTIF functions, but you can use if for anything you can solve with WorkSheetFunctions. A first attempt for those would be t...

In this example we create a goroutine (a function running in a separate thread) that accepts a chan parameter, and simply loops, sending information into the channel each time. In the main we have a for loop and a select. The select will block processing until one of the case statements becomes tru...

1.7+ Timing out an HTTP request with a context can be accomplished with only the standard library (not the subrepos) in 1.7+: import ( "context" "net/http" "time" ) req, err := http.NewRequest("GET", `https://example.net`, nil) ctx, _ := ...

Query: SELECT * FROM Customers ORDER BY CustomerID LIMIT 3; Result: CustomerID CustomerName ContactName Address City PostalCode Country 1 Alfreds Futterkiste Maria Anders Obere Str. 57 Berlin 12209 Ge...