Using statement
The using statement is a shortcut to get an object, execute code, and quickly release the object. There are many objects (referred to as .NET Framework, 淌), such as Graphics, File Handles, Communication Ports, and SQL Connections require you to release these objects yourself to avoid leaks of memory in your application. Suppose you want to draw a rectangle with a brush object:
USING G
As graphics =
Me.creategraphics ()
Using br
As system.drawing.solidbrush =
New solidbrush (system.drawing.color.blue)
G.FillRectangle (Br,
New Rectangle (30, 50, 230, 200))
END Using
END Using
After you run over the graphics and brush object, you must destroy them, and
The USING statement makes it easy for this. Compared to you have used the try / catch statement in Visual Basic .NET and then release the object in the FINALLY block.
The USING statement is simple and refreshing.
Continue statement
The Continue statement can jump directly to the beginning of the next loop, making the logic of the loop more refined, readability is also stronger:
DIM J
As integer
DIM PROD
As integer
For i
As integer = 0
TO 100
J = 0
While J PROD = i * j IF prod> 5000 THEN 'Value of jumping to the next for Continue for END IF J = 1 End while NEXT The Continue statement is very simple and makes the program jumps out of the inner layer loop easier, without having to help a statement tag and one GOTO statement. The Continue statement can act on For, While, and Loop loops. Global keyword Global Keywords can quickly access the topmost root namespace of the namespace, or a space namespace. In the past, you can't define a system.io in the hierarchy of your company's namespace: Namespace mycompany.system.io Doing so will make the application to a reference to the SYSTEM namespace under the framework. But now, you can use it. Global keywords to eliminate the second meaning of namespace: DIM Myfile AS Global.system.IO.FILE At the time of code generation, if you want to make sure that the reference to generate a namespace is absolutely in line with your ideas, then The global keyword is especially useful. I think you will find that Visual Basic uses it in all generated code. Global keyword. @ 以下 below is original for your reference @ USING Statement THE Using statement is a shortcut way to acquire an object, execute code with it, and immediately release it. A number of framework objects such as graphics, file handles, communication ports, and SQL Connections require you to release objects you create to avoid memory leaks In Your Applications. Assume You Want to Draw A Rectangle Using A Brush Object: USING G As graphics = Me.creategraphics () Using br As system.drawing.solidbrush = New solidbrush (system.drawing.color.blue) G.FillRectangle (Br, New Rectangle (30, 50, 230, 200)) END Using END Using You want to dispose of the graphics and brush Objects overce you're done Using them, and the Using Statement Makes Doing this A Snap. The Using Statement Is Much Cleaner Than Using Try / Catch and Releaseing The Object In The finally block as you have to in Visual Basic .NET. Continue Statement The Continue Statement Skips To The Next Iteration of a Loop, Making The Loop Logic More Concise and Easier To Read: DIM J As integer DIM PROD As integer For i As integer = 0 TO 100 J = 0 While J PROD = i * j IF prod> 5000 THEN 'Skips to the next for value Continue for END IF J = 1 End while NEXT THE Continue Statement Is Very Clean and Makes Escaping The Inner Loop Quite Easy Without Resorting to a Label and A Goto Statement. The Continue Statement Operates on for, while, and do loops. Global Keyword THE Global Keyword Makes The root, or empty, namespace at the top of the name, you.................................... .. Namespace mycompany.system.io Doing So Would Mess Up All References To The Framework's System Namespace Wtem Application. You Can Now Use Theglobal Keyword To Disambiguate The namespaces: DIM Myfile AS Global.system.IO.FILE THE Global keyword is especially useful in code generation scenarios where you want to be absolutely sure that generated namespace references point to what you intend. I expect that you'll see Visual Basic itself use the Global Keyword in all generated code.
