Isn t the assignment of the DataTable object in c a reference?

DataTable inherits from MarshalbyValueComponent.

MarshalbyValueComponent itself is an object, so it's a reference type, but this class is encapsulated by value when it is remoting, e.g. DataTable is derived from this class.

Encapsulation means that when remoting, the object of this type passed from the server to the client is not a reference to the object on the original server, but another object after serialization and deserialization by value encapsulation, which is equivalent to a copy of the object on the client side on the server side.

Because it's not a reference type.

using ;

Tell you a way to do it, you don't need to ask for a namespace every time.

If you're using vs2008 or later, as soon as you write this class (e.g. datatable), you'll be prompted to see if the namespace is missing.

At this point, you select the datatable and right-click. Click Parse, at this time there is a namespace on the right, generally you click on the first one.

If you right-click and find that it doesn't parse, it means that you may have written the class name incorrectly, or that you didn't reference the library.

This is a step through a row of data foreach (object obj in

DatarowCollection is a collection, which is a DataRowCollection object...

foreach (datarow dr in

。。。I've never seen anything like this.

This is traversing a row of data foreach (object obj indatarowcollection is a collection, which is the datarowcollection object...).

foreach (datarow dr in

Objects in general have a clone() method, which means a copy.

For example: a a = new a();

a aa = ;

If you don't have this method, you'll have to assign new attributes one by one.

A datatable is a table object, what do you say is the single element in it? All right?

For example: datatable dt=get datatable object;

foreach(datarow row in

Make use of indexes such as table[0][0] to represent the first column of the first row in the table.

Your question is too general, right?,But looking at the return value bool type,It should be the verification result.。

The question was not asked clearly. I don't know what that means.

I don't think so. Maybe it's just an interface?

His index starts with 1 and your int i=0

Change to int i=1 followed by <=

This is a question of pass-by-address or pass-by-value, in general, like int, double, these are value types, then every time you define a variable, you are creating a new memory area to store, that is, in other functions, it is a new address. For example, the datatable type, what is actually passed to the parameter in the system is only a memory address, and the function also changes this address, so you have changed it regardless of whether you return a value or not.

To test whether it is a value type, you can use the following methods.

object o;

The essence of the problem is value types and reference types.

int is the value type.

public int getint()

void getin(int s)