Form1_keydown事件在分隔符和返回键时不起作用 [英] Form1_keydown event doesn't work right when it comes to separator and return keys
问题描述
我试图使用简单的计算器来处理键盘事件。到目前为止一切顺利，除了Keys.Separator和Keys.Return。 =按钮工作正常，这两个keydown事件也与按钮具有相同的代码。它的工作方式很奇怪，就像我说我要总计50和2，当我按下返回或numpad进入查看结果时，它只是不断向第二个变量添加1（无论什么是变量，它总是重复 1s），如果我按一次结果显示为21，如果我一直按回车或小键盘输入，则变为21111111 ...
其他KeyDown事件工作正常，我想知道如果这两个钥匙确实有一个特殊的工作方式......
以下是活动代码：
I was trying to make my simple calculator to work with keyboard events. All is well so far, except Keys.Separator and Keys.Return. = button works fine and these two keydown events also have same codes with the button. it works strangely, like lets say I want to totalize 50 and 2, when I press return or numpad enter to see the result, it just keeps adding "1"s to second variable(doesnt matter what are the variables, it always duplicates "1"s), If I press one time result is shown as 21, If I keep pressing return or numpad enter, it becomes 21111111...
Other KeyDown events work fine, I wonder If these two Keys do have a special way of work...
Here is the code of the event:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Separator||e.KeyCode==Keys.Return)
{
if (equal)
{
sayi1 = sonuc;
}
else
{
sayi2 = Convert.ToDouble(label1.Text);
}
if (topla)
{
sonuc = sayi1 + sayi2;
label1.Text = (sonuc).ToString();
}
else if (cikar)
{
sonuc = sayi1 - sayi2;
label1.Text = (sonuc).ToString();
}
else if (carp)
{
sonuc = sayi1 * sayi2;
label1.Text = (sonuc).ToString();
}
else
{
sonuc = sayi1 / sayi2;
label1.Text = sonuc.ToString();
}
sayi = sonuc.ToString();
equal = true;
}
代码的其他部分如何工作：
How other parts of the code work:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
KeyPreview = true;
}
public string sayi;//this variable is probably useless, i will work on it later
public double sayi1, sayi2, sonuc;//var1,var2,result
public bool topla, cikar, carp, bol, equal;//+,-,*,/
private void button1_Click(object sender, EventArgs e)//1 button
{
if ((topla || cikar || carp || bol) && sayi == "")
label1.Text = "";
sayi += "1";
label1.Text += "1";
}
private void button17_Click(object sender, EventArgs e)//c clear button
{
sayi = "";
label1.Text = sayi;
equal = false;
}
private void button14_Click(object sender, EventArgs e)//- process
{
sayi1 = double.Parse(label1.Text);
sayi = "";
equal = false;
cikar = true;
topla = false; carp = false; bol = false;
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Separator||e.KeyCode==Keys.Return)
{
if (equal)
{
sayi1 = sonuc;
}
else
{
sayi2 = Convert.ToDouble(label1.Text);
}
if (topla)
{
sonuc = sayi1 + sayi2;
label1.Text = (sonuc).ToString();
}
else if (cikar)
{
sonuc = sayi1 - sayi2;
label1.Text = (sonuc).ToString();
}
else if (carp)
{
sonuc = sayi1 * sayi2;
label1.Text = (sonuc).ToString();
}
else
{
sonuc = sayi1 / sayi2;
label1.Text = sonuc.ToString();
}
sayi = sonuc.ToString();
equal = true;
}
else if(e.KeyCode == Keys.D1 || e.KeyCode == Keys.NumPad1)
{
if ((topla || cikar || carp || bol) && sayi == "")
label1.Text = "";
sayi += "1";
label1.Text += "1";
}
private void button12_Click(object sender, EventArgs e)// = button
{
if (equal)
{
sayi1 = sonuc;
}
else
{
sayi2 = Convert.ToDouble(label1.Text);
}
if (topla)
{
sonuc = sayi1 + sayi2;
label1.Text = (sonuc).ToString();
}
else if (cikar)
{
sonuc = sayi1 - sayi2;
label1.Text = (sonuc).ToString();
}
else if (carp)
{
sonuc = sayi1 * sayi2;
label1.Text = (sonuc).ToString();
}
else
{
sonuc = sayi1 / sayi2;
label1.Text = sonuc.ToString();
}
sayi = sonuc.ToString();
equal = true;
}
}
我的尝试：
我分别对这两个事件进行了编码，但没有什么区别。
What I have tried:
I coded these two events separately but didn't make a difference.
推荐答案
Enter是一个特殊键，用于激活按钮，而不是默认情况下通过KeyDown事件处理程序传递。
为了证明这一点，在Form1_keyDown处理程序中添加一个断点，你会明白我的意思 - 它永远不会受到打击。事实上，如果你的表单上有一个输入控件，如文本框或按钮，除非Form.KeyPreview属性设置为true，否则甚至不会为表单生成事件。
要捕获在表单中输入键，最好将=按钮指定为表单的AcceptButton，因为这将导致ENTER单击按钮。
Enter is a "special key" which activates a button, rather than being passed through the KeyDown event handler by default.
To prove this, add a breakpoint to your Form1_keyDown handler and you will see what I mean - it never gets hit. In fact, if you have an input control such as a textbox or button on your form KeyDown events are not even generated for the form unless the Form.KeyPreview property is set to true.
To "catch" the Enter key in a form, you would be best off assigning the "=" button as the AcceptButton for the form as that will cause ENTER to click the button.
它似乎是关于按钮的焦点方法。我将所有按钮的TabIndex属性设置为False，并在每个单击事件中添加了label1.Focus（）方法。这些解决了这个问题。将=声明为主窗体的AcceptButton，导致TabIndex = false不能用于=按钮，所以我不得不使用KeyDown事件进入enter和numpad再次输入。
It seems it was about buttons' focus method. I set all of the buttons' TabIndex properties as False, and added label1.Focus() method in each click event. These solved the problem. Declaring "=" as the AcceptButton of the main form, caused to TabIndex=false didnt work for "=" button, so I had to use KeyDown event for enter and numpad enter again.
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