C# WPF 中的 KeyPress 事件等效
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KeyPress event equivalent in WPF
提问by joseph
i have the following code in WPA, and i am trying to convert it to WPF. I tried Keydown instead of Keypress and changed, for example,
我在 WPA 中有以下代码，我正在尝试将其转换为 WPF。我尝试了 Keydown 而不是 Keypress 并进行了更改，例如，
(e.keyChar == '-') to (e.key == e.Subtract):
- its not working the same
- I cant find the equal sign within e.key
- 它的工作方式不一样
- 我在 e.key 中找不到等号
first code:
第一个代码：
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
foreach (TextBox tb in this.Controls.OfType<TextBox>())
{
tb.Enter += textBox_Enter;
}
}
void textBox_Enter(object sender, EventArgs e)
{
focusedTextbox = (TextBox)sender;
}
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == '+')
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 1;
e.Handled = true;
}
else if (e.KeyChar == '-')
{
if (focusedTextbox != null)
{
if (focusedTextbox.Text == "")
{
e.Handled = false;
}
else
{
e.Handled = true;
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 2;
}
}
}
else if (e.KeyChar == '*')
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 3;
e.Handled = true;
}
else if (e.KeyChar == '/')
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 4;
e.Handled = true;
}
else if (e.KeyChar == '=')
{
e.Handled = true;
operand2.Real = getOperand.Real;
operand2.Imag = getOperand.Imag;
switch (flag1)
{
case 1:
operand1 = operand1 + operand2;
break;
case 2: operand1 = operand1 - operand2;
break;
case 3:
operand1 = operand1 * operand2;
break;
case 4:
if (operand2.Magnitude == 0)
{
textBox1.Clear();
textBox2.Clear();
MessageBox.Show("Cannot divide by a number whose magnitude is zero");
operand1 = new Complex();
operand2 = new Complex();
listBox1.ClearSelected();
}
else
operand1 = operand1 / operand2;
break;
}
string s = operand1.ToString();
if (flag == 1)
{
string[] s1 = s.Split(' ');
if (s1[1] == "-")
{
textBox1.Text = s1[0];
textBox2.Text = "-" + s1[3];
}
else
{
textBox1.Text = s1[0];
textBox2.Text = s1[3];
}
}
else if (flag == 2)
{
string[] s1 = s.Split('@');
textBox1.Text = s1[0].Trim();
textBox2.Text = s1[1].Trim();
}
listBox1.Items.Add(operand1);
}
}
second code:
第二个代码：
private void win_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Add)
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 1;
e.Handled = true;
}
else if (e.Key == Key.Subtract)
{
if (textBox2.Text == "")
{
e.Handled = false;
}
else
{
e.Handled = true;
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 2;
}
}
else if (e.Key == Key.Multiply)
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 3;
e.Handled = true;
}
else if (e.Key == Key.Divide)
{
operand1.Real = getOperand.Real;
operand1.Imag = getOperand.Imag;
flag1 = 4;
e.Handled = true;
}
else if (e.Key == Key.Enter)
{
e.Handled = true;
operand2.Real = getOperand.Real;
operand2.Imag = getOperand.Imag;
switch (flag1)
{
case 1:
operand1 = operand1 + operand2;
break;
case 2: operand1 = operand1 - operand2;
break;
case 3:
operand1 = operand1 * operand2;
break;
case 4:
if (operand2.Magnitude == 0)
{
textBox1.Clear();
textBox2.Clear();
MessageBox.Show("Cannot divide by a number whose magnitude is zero");
operand1 = new Complex();
operand2 = new Complex();
listBox1.UnselectAll();
}
else
operand1 = operand1 / operand2;
break;
}
string s = operand1.ToString();
if (flag == 1)
{
string[] s1 = s.Split(' ');
if (s1[1] == "-")
{
textBox1.Text = s1[0];
textBox2.Text = "-" + s1[3];
}
else
{
textBox1.Text = s1[0];
textBox2.Text = s1[3];
}
}
else if (flag == 2)
{
string[] s1 = s.Split('@');
textBox1.Text = s1[0].Trim();
textBox2.Text = s1[1].Trim();
}
listBox1.Items.Add(operand1);
}
}
回答by Will Faithfull
It's very similar - but you compare e.Key to the Key enumeration.
它非常相似 - 但您将 e.Key 与 Key 枚举进行比较。
Register your event handler somewhere (such as the constructor, or window_loaded):
在某处注册您的事件处理程序（例如构造函数或 window_loaded）：
private void Window_Loaded(object sender, RoutedEventArgs e)
{
this.KeyDown += new KeyEventHandler(MainWindow_KeyDown);
}
And then in the event handler:
然后在事件处理程序中：
void MainWindow_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Subtract)
{
// Do something
}
}
回答by phoog
You're looking for the TextInputevent, or perhaps PreviewTextInput.
您正在寻找TextInput事件，或者PreviewTextInput。
The EventArgs type is TextCompositionEventArgs; I believe you want the Textproperty here, but I'm not at all sure of that.
EventArgs 类型为TextCompositionEventArgs；我相信你想要Text这里的财产，但我完全不确定。
回答by MaxEcho
<TextBox x:Name="txtbx" KeyDown="OnKeyDownHandler" Height="23" Width="250">
</TextBox>
private void OnKeyDownHandler(object sender, KeyEventArgs e)
{
if (e.Key == Key.Return)
{
txtbx.Text = "You Entered: " + txtbx.Text;
}
}
