Most voted "winforms" questions
Winforms is the informal term given to Windows Forms, is a graphical interface application included as part of Microsoft . NET Framework. Winforms provides native visual access to Microsoft Windows window interface using existing Windows API in managed code.
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answers315
viewsC# Bina with Usb Fax Modem
I would like to know a way to get the phone number of a fax modem usb, using C#. Example: I have a computer with a fax modem usb connected to a telephone line, when someone calls me my system picks…
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answer384
viewsPass data from one form to another class
I have very cute Form1 with very cool button and inside it I have a toggle button on-off. I have another class.Cs and I have a condition in it, but it will only perform if that boot there on Form1…
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answers216
viewsWhat are the advantages of working with Fluent Interface with LINQ?
What are the advantages of working with a fluent LINQ interface? I have that code: Employees.Cs. namespace LinqConsulta { class Empregados : List<Empregado> { public Empregados Lista() {…
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answer1688
viewsClick button call different methods
I have a button that calls the click event btn_Salvar in my form. How do I call this event different methods according to who created the form in which the button is contained? EDIT: Explaining…
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answer2301
viewsSQL Sends NULL value to a Datetime column
I have a form in VB.NET where the user informs the delivery dates and delivery forecast of the order and other information. Since he does not yet have, for example, the delivery date because he has…
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answers1618
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answer154
viewsDatetimepicker with custom dates
I am developing a consultation marking system in Windows Forms and had the idea to include a DateTimePicker where only dates with available vacancies must be "clickable" by the user. There’s a way…
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answers477
viewsValidation of Textbox
I have the following piece of code that limits a TextBox receivable only numbers and comma: private void txtTempoAcel1_KeyPress(object sender, KeyPressEventArgs e) { if (!Char.IsDigit(e.KeyChar)…
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answers164
viewsHelp with textbox validation
Guys good afternoon. I’m having difficulty performing a task, which is as follows:: I have a customer registration, that when the user edits something from the register, when saving is presented a…
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answers2496
viewsDo not open more than one form at the same time in C#
I’m developing a system that’s practically a CRUD. My problem and the following: when I open a screen of my system, if I click on the menu to open again, it has two windows open, that is, if I click…
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answers2514
viewsHow to delete a specific line from a file?
My goal is that when the user removes an item from a Listbox, the program delete a certain line from a file. I have this text in a file .txt: linha1 linha2 linha3 In the Listbox contains the…
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answer94
viewsHow to detect Network Instability with C#
I have a Winforms system where the folders that this system generates and uses stay on a server, but there are some routines of this system that keep creating several PDF’s on the server, and when…
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answers557
viewsAdd hyperlink to Messagebox c#
It is possible to customize the MessageBox.Show("http://www.google.com/"); so that this link is a hyperlink and when I click open a browser? The only possibility really would be to create a new…
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answer265
viewsExit Standard Event on ESC key
Currently in my system I use the event KeyPress to identify the key Esc and so close my form, but I have a very large system with more than 50 forms and even more being developed: My question is: Is…
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answer899
viewsError opening Sqlconnection
The following I have a gridviewer that is connected to a Query with a Table called Server Table. I want to add some things to the columns gives the following error Instance failure. In this part of…
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answer78
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answer518
viewsWhere should I put Connectionstring in Windows Forms Applications with EF?
I have the following error using Entity Framework: Additional information: No Entity Framework Provider found for the ADO.NET Provider with invariant name 'System.Data.Sqlclient'. Make sure the…
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answers520
viewsChanging Rows in Datagridview / Opening a form with different design
I have a problem in a school project, as stated in the title, I need to change Rows and open a form that already has your design, but with different things, come on: The program is very simple, a…
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answer3993
viewsWebbrowser in C# using Chrome
I have a browser application that I created using the class WebBrowser of System.Windows.Forms, this class uses the browser engine IE. Now I need to create a browser application using Chrome. What’s…
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answer45
viewsThe interface freezes while loading an event
I did an event with a lot of time consuming operations and I need to keep describing the operations in a Richtextbox, so I use Richtextbox.Appendtext("Something"), only what I wrote only appears…
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answer517
viewsHow to modify a window in Windows Forms?
How to change the appearance of Window borde, Title bar and button, and status bar in Windows Forms?
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answers257
viewsShow property value instead of class name in Datagridview
I have a Datagridview that should show data between related tables and I can’t get it to show the data correctly, it shows the namespace name followed by the class name. I saw some things and showed…
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answer157
viewsCommunicate ASP.NET with Windows Forms
The problem is the following, I work with SAT-CFE and the communication with this is done via USB which makes it impossible for my web system to do direct communication with it. What I did, I…
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answer114
viewsOrganizing forms inheritance - C#
I’m doing a program for selling products and I have a design problem. The differential of this program is that it can take on two different faces: one for the sale of chocolates and the other for…
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answer61
viewsMove button controls in a Windows Forms application inside a panel container
I have a form with three buttons, are they: btnVendas, btnFunctionaries, btnConfig. And they’re lined up inside a Panel container. I need these buttons to be clicked and held by the mouse pointer so…
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answer902
viewsHow to use Event Eventargs
Maybe the question was too comprehensive, but I wanted to know how to use the EventArgs of certain components, such as EventArgs in the Button_Click. Explaining the doubt a little better, for…
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answers535
viewsImport a list to another Form C#
I don’t know how to import a list to another form, if anyone can help me. The code of the first form is like this: Note that I want to Transport the ListaFornecedores to the Form FrmNovoProduto.…
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answer102
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answer4068
viewsHow to show error message?
I am developing a C# register in Visual Studio and created a method to include a new record in the database. The method is as follows:: public static bool Inserir(Usuario pUsuario) { try {…
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answers3157
viewsStart Windows Forms program in the background
I developed a monitoring application using Windows Forms, but it has no need to have anything visual at the moment, so I would like when running it, it to be executed in the background (I would like…
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answers1643
viewsVariable in message box c#
How to put a variable inside the message box? The code comes below I think is self-explanatory. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using…
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answer105
viewsMonitor opening of Forms C#
I need to monitor the opening of Forms within a C#application. For example, every time you open a Form within the application, the application must execute a method or trigger an event with…
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answer836
viewsHow to start a textbox with a value of 0 (zero)?
I have a form created with Windows Forms, and in this form I have textbox who will receive numbers. How do I make this textbox, when initializing, is already filled with value 0, that is when I open…
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answer6570
viewsPath access error denied
I am with a program created in Visual Studio / Windows Forms. In it access the following file to get some information: 1st Code (works normal) StreamReader file = new StreamReader(@…
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answer359
viewsHow to reset the Datasource property of a Datagridview and not delete the Header columns?
I’m filling my Datagridview with a list of objects, but when I fill the grid for the first time it’s all right. When Seto the Datasource property is null, the grid columns are deleted. There is the…
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answers2857
viewsHow to make a string in Appsettings and use it later
How can I make a string in Appsettings, and then use it, for example, the string in Appsettings is this: string example = "example" And take the value that’s in the Appsettings string and put it in…
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answer444
viewsHow to project an image on the big screen?
I’ve looked on the Internet and I can’t find. How do I project an image onto the screen ? Example: On the main screen(notebook) show executable(windows Forms), and on the second screen show an image…
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answers718
viewsForm behind the Windows bar
What is happening and the following, when I set the form in c# visual studio 2015 to maximized, the bottom of the form is behind the windows taskbar, how can I solve the problem. Follows the code:…
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answer328
viewsHow to show a Messagebox when selecting an item in the combobox
I would like to know how to implement in my combobox one Messagebox when selecting an item from the list? Example: Combo list: Junior Maria Joseph When selecting Maria, a message box appears…
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answers699
viewsX509 - Key set is not set
I use the class x509certificate of C# to read a certificate A3 for the signature of XML, occurs that it was necessary to renew the certificate and at first nothing changed, continued same type, but…
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answer162
viewsLoad the combobox
When save a dice in the combo box, and in this combo box has two options (gasoline, diesel, alcohol, natural gas) When I select diesel and save it works normally. The problem is when I want to load…
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answer53928
viewsHow to resolve Object Reference Not Set To An Instance Of An Object
I have a serious problem. I have a Gridview populated with data from a Mysql BD working perfectly. I also have a button to turn it into a table to be inserted into a PDF using iTextSharp that also…
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answer30
viewsHow to invert Control.Controlcollection’s list of controls?
I am inserting in a Panel several Labels, as I am inserting, the first Label becomes last in Panel. But I wanted to reverse this process. I wanted the first Label that was inserted to be in the…
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answer403
viewsAsync method returning a List<string> how to use?
I have a method called consulta_usuario_email, that is responsible for searching in the table of registered users, the emails of users of a certain department: public async…
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answer118
viewsHow to put € symbol on Datagridview
I have a Datagridview with numerical values and some of them represent monetary values, but from the database comes only the number and wanted to put the currency symbol in front of the value. This…
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answers311
viewsChange tab of Tabcontrol
I am creating a Windowsform template and I am using a Tabcontrol and would like to create an event that changes the tab that is being displayed. I was able to change the content displayed with…
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answer51
viewsForm running after closed
I have an app with a Form1, where is my pictureBox. I added another Form2 to the project that when executing it it becomes a magnifying lens, thus, you can use on top of the first Form1. My problem…
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answer390
viewsMask with Regex and replace to allow single digits and a single hyphen
What I need: A mask that works in the event keypress of a TextBox replacing what is not numerical and excessive hyphens with "". What is my difficulty: Check the entry of only one hyphen in the same…
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answers254
viewsProblem calling Virtual Keyboard - Winforms
I have a button that when clicking the virtual keyboard of windows is called. Process.Start("osk.exe"); By clicking the button an Exception is triggered: System.ComponentModel.Win32Exception: 'The…
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answers73
viewsMark All Checkbox in a groupbox
I have a program that in a groupbox has several checkbox, as there are many and I thought of making a button to select all at once, to be more practical, but there arose a doubt, as I can do when…