c# - 使用键盘上的 Enter 等同于计算器

Question

当我尝试使用键盘上的 Enter 键时，它总是输入最近在屏幕上按下的数字。我想在键盘上使用 Enter 键，而不是输入用户最近在屏幕上按下的数字。

我正在使用 Visual Studio Community 2013 用 C# 编写一个计算器。

public calculatorForm()
{
        InitializeComponent();
}

// Manages the numeracy and period buttons
private void mathematicalButtons_Click(object sender, EventArgs e)
{
        if ((calculatorResults.Text == "0")||(operationPressed))
            calculatorResults.Clear();

        operationPressed = false;

        Button a = (Button)sender;

        if (a.Text == ".")
        {
            if(!calculatorResults.Text.Contains("."))
                calculatorResults.Text = calculatorResults.Text + a.Text;
        }
        else
            calculatorResults.Text = calculatorResults.Text + a.Text;            
}

// Manages the addition, subtract, multiplication, and divide buttons
private void operatorButtons_Click(object sender, EventArgs e)
{
        Button a = (Button)sender;

        if (value != 0)
        {
            equalButton.PerformClick();
            operationPressed = true;
            operation = a.Text;
            equationLabel.Text = value + " " + operation;
        }
        else
        {
            operation = a.Text;
            value = double.Parse(calculatorResults.Text);
            operationPressed = true;
            equationLabel.Text = value + " " + operation;
        }
}

// Manages the clear button
private void clearButton_Click(object sender, EventArgs e)
{
        calculatorResults.Text = "0";
        value = 0;
        equationLabel.Text = "";
}

// Manages the clear entry button
private void clearEntryButton_Click(object sender, EventArgs e)
{
        calculatorResults.Text = "0";
}

// Manages the equal button
private void equalButton_Click(object sender, EventArgs e)
{
        equationLabel.Text = "";

        switch (operation)
        {
            case "+":
                calculatorResults.Text = (value + Double.Parse(calculatorResults.Text)).ToString();
                break;

            case "-":
                calculatorResults.Text = (value - Double.Parse(calculatorResults.Text)).ToString();
                break;

            case "*":
                calculatorResults.Text = (value * Double.Parse(calculatorResults.Text)).ToString();
                break;

            case "/":
                calculatorResults.Text = (value / Double.Parse(calculatorResults.Text)).ToString();
                break;

            default:
                break;
        }

        value = Double.Parse(calculatorResults.Text);
        operation = "";
}

// Allows user to use computer keyboard to enter data
private void calculatorForm_KeyPress(object sender, KeyPressEventArgs e)
{
        switch (e.KeyChar.ToString())
        {
            case "0":
                zeroButton.PerformClick();
                break;

            case "1":
                oneButton.PerformClick();
                break;

            case "2":
                twoButton.PerformClick();
                break;

            case "3":
                threeButton.PerformClick();
                break;

            case "4":
                fourButton.PerformClick();
                break;

            case "5":
                fiveButton.PerformClick();
                break;

            case "6":
                sixButton.PerformClick();
                break;

            case "7":
                sevenButton.PerformClick();
                break;

            case "8":
                eightButton.PerformClick();
                break;

            case "9":
                nineButton.PerformClick();
                break;

            case ".":
                periodButton.PerformClick();
                break;

            case "/":
                divideButton.PerformClick();
                break;

            case "*":
                multiplicationButton.PerformClick();
                break;

            case "-":
                subtractButton.PerformClick();
                break;

            case "+":
                additionButton.PerformClick();
                break;

            case "=":
                equalButton.PerformClick();
                break;

            default:
                break;
        }
    }
}

Answer 1

这里的问题是，当您按下回车键时，具有焦点的控件会捕获该事件。当你点击一个按钮时，你给了它焦点，所以下次你点击 enter 时，该按钮将捕获事件，在按钮的情况下，enter 键被解释为按下按钮。

您想要的是表单始终具有焦点，这样您就知道关键事件将始终转到表单而不是任何其他控件(例如按钮)。为此，请查看以下问题的答案:C# Stop Button From Gaining Focus on Click

如果您需要更多帮助，请告诉我!