添加到Visual Studio C＃项目中的按钮无法识别Click事件

Question

I am new to Visual Studio and C#. I have created my first project -- an inventory application using MySql -- and everything works. But I needed to add a new button to the form for deleting records, so I dragged it in from the toolbox, changed the text ("Delete Product") and changed the design name ("DelBtn"). Adding the tool did not create the event handler, so I added the following with the MessageBox for testing:

private void DelBtn_Click(object sender, EventArgs e)
{
    MessageBox.Show("Delete button clicked");
}

Clicking the button, however, has no effect, no MessageBox or anything else. Can someone help, please?

Answer 1

Go to your form designer, right-click your button, and select "Properties". In the properties window, there will be an "Events" button (it looks like a lightning bolt). Click that, and look for the Click event of your button. Make sure that DelBtn_Click is listed there. At that point, the button should respond with your code.

Hope this helps!

Answer 2

You need to make sure you've wired up the handler correctly. Look for the designer file that gets generated along with your form (I'm making the assumption that this is winforms).

Then you'll need a line like this in your InitializeComponent method:

this.button1.Click += new System.EventHandler(this.DelBtn_Click);

You don't have to do this in your designer file, you can do it anywhere you want that runs before your form is shown, eg the constructor. But it seems to me like something you did -- maybe by manually-renaming your event handler method -- has mangled the automatically-generated designer code that I mentioned above, and you probably just need to fix what's there already.

Answer 3

如果需要，您需要在designer.cs中委派事件：

DelBtn.Click += new System.EventHandler(this.DelBtn_Click);

Answer 4

Just adding a method with the same name as VS would have made for you won't bind the event to that method. Open the properties for the button and at the top of the resulting panel you'll see a lightning bolt. Click that and find the event you want and type in your method name there.

Answer 5

You need to go on the form, click on the button, on the properties menu you need to click on event,find onclick and double click the blank space. It will automatically create the onclick method for you.