Every day, there are VB6 programmers start to transfer .NET development, and the most important issue they face, is to habits. Net in the object-oriented golden jade law. Therefore, the forum will always hear the netizens discuss how to visit the form between the forms of the form in Visual Basic .NET 2003. Earlier, I published it.
An article on this problem solution, by overwriting the Sub New, using the Me keyword to obtain an example of another form in a new form. Now that the era of VB2005 is coming soon, will there be a simpler way? The answer is yes, all the mystery is hidden in My.Forms namespace!
In fact, this book is not worth a big book, and maintains the default instance of any form class, which provides this feature in the early versions of VB. In .NET 2003, VB, to pursue this characteristic in order to pursue and other object-oriented language style. While the VB2005 is innovating, Microsoft seems to look at the characteristics of those deleted in VB6 from a more rational perspective (existed is rational, isn't it?
), The default class of the maintenance form is a technology that is re-picked up. However, now all the default instances of all forms are unified under My.Forms namespace (such as my.forms.form2), change the style of VB6 in chaos (OOPS, Xi Hua Warcraft to play fire into the magic Ha ha). But despite this, when you write the code, you can still omit the previous My.Forms, such as you can write in form2.vb:
Private sub button1_click
BYVAL Sender
As system.object,
ByVal E
As system.eventargs _
Handles button1.click
Form1.text = "Hello My.Forms"
End Sub
Haha, is it a feeling that VB6 is found?
In fact, when I just came into contact with this feature in 2005, I am still not suitable. Because it is used to the development of 2003, I always go to New a form yourself. So I once surprised, if each startup program, I automatically generate a default form instance for us, if we can't use this instance, isn't it very waste of memory? Actually, it is not the case, I think it is necessary to say here.
When Visual Basic is executing your code, when you encounter a reference to my.forms, Say, Form2, then, the first thing it does is to judge the default instance of the FORM2 form (note, it is the default Examples instead of your own new examples have been created. If so, use this instance; if any, you create a default instance. That is, if you don't have my.forms.form2 in your code, the default instance of FORM2 will not be created at all! So, My.Forms namespace is just the default instance of the automatic maintenance of the form, not automatically created. Similarly, MY.FORMS is generally not responsible for automatic recycling of the default instance.
I have always emphasized the word "default", because I want you to remember, by default, it is just a default, it still has a little limit: if you have to get a form instance, it will not It is included under My.Forms space. So I want to say, if a form in your program needs to be created, the form of formal visit technology in VB2003 is still necessary. I have written a bit rush, and I didn't write the details of the code, so some netizens complained to me. Take advantage of this opportunity to explain it in detail: I still assume that your main form name is form1, the new form class is form2, then you will now rewrite the Sub New of Form2 so that it can accept the main form. Example. You may have found that you can't find the original Sub New? That's right, VB 2005 Beta hides the code for Windows automatically generates the code. Do you think of VB6? Oh, you and I have the same illusions. In fact, these codes are not hidden, just being separated to form2.designer.vb file (do not believe, you go to see
). In fact, this is a newly strange feature in VB2005, called Partial Types or part of the type. Limited to the space, the introduction of some types is given here.
First define a FORM1 type global variable in Form1 type:
Dim frmmain
AS Form1
Then rewrite the Sub New so that frmmain points to the incoming Form1 instance:
Sub New
ByVal FRM
As Form1)
Myclass.new ()
frmmain = frm
End Sub
Back to FORM1.VB, we create an instance of a FORM2:
DIM FRMNEW
AS New Form2
ME)
Now you can call the main form instance with your heart with your heart in Form2.vb.
When you mention Sub New, you can also rewrite directly in Form2.Designer.vb, but since Microsoft seizes these code, on the one hand, it is to avoid contamination, so unless you are a old bird, I don't recommend you. this way.
The end of the article, let us return to the MY keyword of Visual Basic 2005. My showed us that she is vigorous, but you look carefully, but you can still find some flavors of returning, such as the exchange of the form, just this. In short, My is a new feature worth of a big book special book in VB2005. If you want to know more about my keyword now, you can refer to me first.
A very simple translation of My, then I will try it with a smart real. If you want to learn more in more detail, including the type mentioned above, you will go to the blog of my brother Ninputer.
Go to the head in the assembly (that there are the most detailed) I have seen so far). I think you know a new feature of My, you will be sighing: "Oh, my god!"
