private

问题 What is the use of having destructor as private? 回答1: Basically, any time you want some other class to be responsible for the life cycle of your class' objects, or you have reason to prevent the destruction of an object, you can make the destructor private. For instance, if you're doing some sort of reference counting thing, you can have the object (or manager that has been "friend"ed) responsible for counting the number of references to itself and delete it when the number hits zero. A

问题 What is the use of having destructor as private? 回答1: Basically, any time you want some other class to be responsible for the life cycle of your class' objects, or you have reason to prevent the destruction of an object, you can make the destructor private. For instance, if you're doing some sort of reference counting thing, you can have the object (or manager that has been "friend"ed) responsible for counting the number of references to itself and delete it when the number hits zero. A

问题 This is an example from "Effective Python", that I am clearly missing something on. I added a few print's to help convince myself, but I'm still a little unclear. I understand that when you attempt to access an inherited private variable, it fails because in the instance dictionary of the child, the name has been mangled (last line below, attempting to access a.__value rightfully fails because the instance dict contains the mangled version _ApiClass__value ). Where I'm getting tripped up is

问题 This is an example from "Effective Python", that I am clearly missing something on. I added a few print's to help convince myself, but I'm still a little unclear. I understand that when you attempt to access an inherited private variable, it fails because in the instance dictionary of the child, the name has been mangled (last line below, attempting to access a.__value rightfully fails because the instance dict contains the mangled version _ApiClass__value ). Where I'm getting tripped up is

问题 I am creating Labels dynamically from a private sub, and I want to be able to do something when the user clicks on them. However, I can't use "Dim withEvents blah..." because it says withEvents can't be used on a local variable but I also can't use "Public withEvents blah" from within my Private Sub. How do I accomplish this? Thanks. 回答1: When you create dynamic control, you can add a handler for it Dim mylbl As New Label mylbl.Name = "button1" mylbl.Text = "hi" Me.Controls.Add(mylbl)

问题 This is a follow up to this issue HERE. After creating new ssl certificates, I created new certs specfically for PayPal use. I have three certficates in play for PayPal which are the private key set to 440, public key set to 644, and PayPal key that I downloaded after uploading the public key, and that key is also set to 644. I also copied over the Cert ID. All keys are being used as proven by my logging, however I am getting the infamous: "We were unable to decrypt the certificate id" There

问题 I have some code which adds a few objects to a vector. I then wish to retrieve a specific object from the vector and be able to both write out and edit its private member variables. This is the code I currently have: class Product { public: Product(int n, const string& na, int p) : number(n), name(na), price(p) {}; void info() const; private: string name; int number, price; }; The member function looks like this: void Product::info() const { cout << number << ". " << name << " " price << endl

问题 So, this works ALMOST as intended. I have the bot private messaging the user who uses the correct command in the correct channel of the server. Instead of clogging up the server with profile creation messages, I have the bot do profile creation privately. I know/think the problem is with the message.channel.awaitMessages, because it only sees the replies in the original channel on the server where the command was put into place. I am not sure what I should replace the message.channel

问题 so, i have to make an application that creates results, i have completed everything, I think???? but i dont know how to get me private method outputData to output the array results from the private method getValue. This is what i have // CreateResults.java // Create poll results and output them to a file. import java.io.FileNotFoundException; import java.util.Formatter; import java.util.FormatterClosedException; import java.util.IllegalFormatException; import java.util.NoSuchElementException;

问题 There are some fields present in table which i don't want to be visible outside? Like created_on, is_first etc. I want to set value of these fields by using callbacks with in model but not accessible for some one to set it. 回答1: The standard way to prevent mass-assignment on certain fields is attr_protected and attr_accessible : http://api.rubyonrails.org/classes/ActiveModel/MassAssignmentSecurity/ClassMethods.html In your case, you would have to add this line in your model: attr_protected