C++

The concept of const is a variable that contains unchangeable values.Constant expressions are fully computed during compilation. Therefore, constants cannot be initialized by extracting values from a variable.If const int A = B + 1; B is a variable,

The hash algorithm generates a small binary "fingerprint" for a file. From a statistical perspective, different files cannot generate the same hash code. To generate a hash code, you must first Create a HashAlgorithm object and use the HashAlgorithm.

I have always been curious about searching and filtering. I think they are very technical, and only very NB talents can do it. I really want to know how they work. To implement such a function, do the design have to be very NB very strange? Do the

Copy codeThe Code is as follows: using System; Using System. Collections. Generic; Using System. ComponentModel; Using System. Data; Using System. Drawing; Using System. Linq; Using System. Text; Using System. Windows. Forms; Using System. Text.

Copy codeThe Code is as follows: private void button2_Click (object sender, EventArgs e) { // Create a request for the URL. WebRequest request = WebRequest. Create ("http://www.baidu.com /"); // If required by the server, set the

Copy codeThe Code is as follows: // call an API [System. Runtime. InteropServices. DllImport ("user32.dll", CharSet = System. Runtime. InteropServices. CharSet. Auto, ExactSpelling = true)] Public static extern IntPtr GetForegroundWindow (); //

1. The crystal table does not recognize the DataTable or DataSet data type returned by the WS interface. The system will prompt "unable to load URL" 3. C # Call the Oracle Package and return the data list 2. After verification, the string type can

C # obtain the remote image. The Authorization authentication of the Form user name and password is required. Copy codeThe Code is as follows: using System; Using System. Collections. Generic; Using System. Drawing; Using System. IO; Using System.

Yield cannot be separately placed in the try-catch Block. If there is yield in the try, the try block cannot be followed by the finally block; it cannot also appear in the anonymous method, it seems that yield is not commonly used, but it is not

Copy codeThe Code is as follows: private void button2_Click_1 (object sender, System. EventArgs e) { String pathName; If (this. openFileDialog1.ShowDialog () = System. Windows. Forms. DialogResult. OK) { PathName = this.

1. Definition of delegation A delegate can be regarded as a data type and can be used to define the acceptable value of a variable as only one method. Simple example of delegation: Copy codeThe Code is as follows: namespace DelegateDemo { Class

Partial Class is introduced in C #2.0, and Partial Method is introduced in C #3.0. These two syntax features share the same characteristics) the method code is scattered in multiple places. 1. features and applications of the Division class 1.1

For example, there are two strings: Copy codeThe Code is as follows: var a = "a-B = c12 "; Var B = "a. B ___ c12 "; Well, obviously, no matter which common method you use, their comparison result is definitely not 0, because they are not of the

The lazy loading design mode is designed to avoid unnecessary performance overhead. The so-called delayed loading is when data (read attribute values) is really needed, to load data. For ease of understanding, let's create a scenario. Suppose we

C # Coding often involves code comments. Common comments include: 1) single line comment. Format: // Comments 2) multi-line comment. Format:/* Comments ...*/ C # introduces a new XML comment, that is, we start a new line before a function, input //,.

In C #, some types can be implicitly converted. I have sorted out these types that can be implicitly converted for your reference. Copy codeThe Code is as follows: static private bool CanConvert (Type from, Type) { If (from. IsPrimitive & to.

　　Preface I have never seen c ++ in the system, because I understand some basic c syntaxes and use c ++ in actual programming. I found that although this can accomplish most of the work, but sometimes the efficiency is too low. For example, the use

Copy codeThe Code is as follows: private void SaveThumbnail (Bitmap originBitmap, int width, int height, string directory, string filename, string extension) { Var physicalPath = directory + filename + extension; Using (var newImage = new Bitmap

Web. Config, some of which are configured as follows: Copy codeThe Code is as follows: ProviderName = "System. Data. SqlClient"/> Make some preparations before encryption. First, reference the space used. Copy codeThe Code is as follows: using

It's actually very simple... C # displacement OPERATOR: Left shift: Shift right:> Displacement may be easier to understand: in fact, the data is converted to the left and right movement of the binary; right shift to left fill 0, left shift to