Control.TextChanged 事件
定义
public:
event EventHandler ^ TextChanged;
public event EventHandler TextChanged;
member this.TextChanged : EventHandler
Public Custom Event TextChanged As EventHandler
事件类型
示例
下面的代码示例更改 ForeColor 了 TextBox 显示货币数据的的。The following code example changes the ForeColor of a TextBox displaying currency data. 该示例将文本转换为十进制数字, ForeColor Color.Red 如果数字为负,则将更改为, Color.Black 如果数字为正,则更改为。The example converts the text to a decimal number and changes the ForeColor to Color.Red if the number is negative and to Color.Black if the number is positive. 此示例要求具有一个包含的 Form TextBox 。This example requires that you have a Form that contains a TextBox.
private:
void currencyTextBox_TextChanged( Object^ /*sender*/, EventArgs^ /*e*/ )
{
try
{
// Convert the text to a Double and determine if it is a negative number.
if ( Double::Parse( currencyTextBox->Text ) < 0 )
{
// If the number is negative, display it in Red.
currencyTextBox->ForeColor = Color::Red;
}
else
{
// If the number is not negative, display it in Black.
currencyTextBox->ForeColor = Color::Black;
}
}
catch ( Exception^ )
{
// If there is an error, display the text using the system colors.
currencyTextBox->ForeColor = SystemColors::ControlText;
}
}
private void currencyTextBox_TextChanged(object sender, EventArgs e)
{
try
{
// Convert the text to a Double and determine if it is a negative number.
if(double.Parse(currencyTextBox.Text) < 0)
{
// If the number is negative, display it in Red.
currencyTextBox.ForeColor = Color.Red;
}
else
{
// If the number is not negative, display it in Black.
currencyTextBox.ForeColor = Color.Black;
}
}
catch
{
// If there is an error, display the text using the system colors.
currencyTextBox.ForeColor = SystemColors.ControlText;
}
}
Private Sub currencyTextBox_TextChanged(sender As Object, _
e As EventArgs) Handles currencyTextBox.TextChanged
Try
' Convert the text to a Double and determine if it is a negative number.
If Double.Parse(currencyTextBox.Text) < 0 Then
' If the number is negative, display it in Red.
currencyTextBox.ForeColor = Color.Red
Else
' If the number is not negative, display it in Black.
currencyTextBox.ForeColor = Color.Black
End If
Catch
' If there is an error, display the text using the system colors.
currencyTextBox.ForeColor = SystemColors.ControlText
End Try
End Sub
注解
如果 Text 编程修改或用户交互更改了属性,则会引发此事件。This event is raised if the Text property is changed by either a programmatic modification or user interaction.
有关处理事件的详细信息,请参阅 处理和引发事件。For more information about handling events, see Handling and Raising Events.