Windows Forms C# - Forms and Dialogs

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Forms and dialogs in Windows Forms are windows that contain controls. They can be different types: to have or to not have a frame, to be modular or not to be, to be stretchable or not to be, to be above all other windows or not to be, and so on. The System.Windows.Forms.Form class The System.Windows.Forms.Form class is a base class for all for

c# Get selected item text from combobox

C# Combobox defined with name my_combobox
private System.Windows.Forms.ComboBox my_combobox;

Read the text of the selected combobox item and assign it to string variable, then show it in message box.
string selected_item_text = my_combobox.GetItemText(my_combobox.SelectedItem); MessageBox.Show(selected_item_text);


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2017/10/18 06:03

Deploy ASP .NET MVC application using LocalDB to local IIS

| 2017/10/18 05:49
When ASP application is published to IIS using LocalDB accessing the database may result in the following error:

Server Error in '/Application_Name' Application.A network-related or instance-specific error occurred while establishing a connection to SQL Server.
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c# combobox fill from database

To get only the unique /distinct/ data table records from any database connected to DataSet in C# project and to put them inside combobox.Fill the table adapter with the records from database.
this.myDBTable_TableAdapter.Fill(this.myDB_DataSet.myDBTable);
Create a view containing the database table
DataView view = new DataView(this.myDB_DataSet.myDBTable);

Copy only the distinct records to new data table.
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2017/10/05 03:18

Get latest date record - SQL query

To return the latest record (one record only) from data base table where one of the fields is in Date/Time format:
SELECT TOP 1 * FROM table_name ORDER BY date_time_column_name DESC
Notes:
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2017/10/05 03:02

c# combobox set selected item by item's text

C# Combobox defined with name my_combobox
private System.Windows.Forms.ComboBox my_combobox;

Define string variable with the text of the combobox item that has to be selected. For example, if the combobox items have text values "item_a" "item_b" "item_c" ... and the item which text is "item_b" has to be selected
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2017/10/05 02:52

C# - Get database connection string from Web.config file


To get the database connection string from IIS Web.config file using C# code, include System.Configuration directive and then create a string variable to assign the connection string like this:
using System.Configuration;
string connStr = ConfigurationManager.
                  ConnectionStrings["connectionString_Name"].ConnectionString;
If “ConfigurationManager” is not recognized you will need to add reference to: "System.Configuration".See: C# - How to add reference to project


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2017/10/05 02:45

C# Textbox - enter only positive numbers on KeyPress event in Windows form application


To prevent users from entering incorrect data in Windows form application, set restriction to allow only specific characters to be entered in the text box.This example uses KeyPress event to monitor the users input and to apply the restriction required.To avoid code duplication in Windows multiform applications for example, a separate class file is created “CommonFunctions.cs”.
The function to allow only numbers in textbox control is named InputNumbers.
For each Windows form, create a single KeyPress event and call the InputNumbers function inside it.
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2017/10/05 02:27

c# passing data between forms

C# project with two forms
public partial class Form1 : Form // this is the main form

public partial class Form2 : Form // this is the second form
To pass variables (values, data) from Form1 to Form2
Case: public variables in Form2
public string input_variable; // put this in Form2 as global variable

public string output_variable; // put this in Form2 as global variable

in Form1 inside the function that run (call) Form2
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2017/10/05 02:07

C# How to draw shapes – Circle, Rectangle, Arc, Pie, Polygon, Bezier, Text

In order to draw shapes in C# a start point and end point coordinates, and a Pen control must be defined first.
Coordinates in C#The value of x is the location of the point along the x-axis, the 0 is at the extreme left. The value of y is the location of the point along the y-axis, the 0 is at the extreme top.
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2017/10/05 01:56