C# WPF如何创建带有验证和绑定的自定义文本框
我正在开发一个用于货币编辑的自定义文本框。C# WPF如何创建带有验证和绑定的自定义文本框,c#,wpf,xaml,binding,custom-controls,C#,Wpf,Xaml,Binding,Custom Controls,我正在开发一个用于货币编辑的自定义文本框。 我见过一些现成的,但它们很复杂和/或不是真正可用的,迫使您采用错误的做法(例如硬编码应该在控件上使用的名称)。 所以我决定自己做,但我在使用绑定选项时遇到了麻烦,因为分配给绑定属性的属性必须是十进制,但TextBox控件的Text属性接受字符串。 我认为答案可能是,重写基类(TextBox)中Text属性的访问方法(getter和setter),但这是不允许的。 “我的绑定”应设置为值,该值设置文本框的文本属性,将其格式化为文本(带有货币符号和所有内容
我见过一些现成的,但它们很复杂和/或不是真正可用的,迫使您采用错误的做法(例如硬编码应该在控件上使用的名称)。
所以我决定自己做,但我在使用绑定选项时遇到了麻烦,因为分配给绑定属性的属性必须是十进制,但TextBox控件的Text属性接受字符串。
我认为答案可能是,重写基类(TextBox)中Text属性的访问方法(getter和setter),但这是不允许的。
“我的绑定”应设置为值,该值设置文本框的文本属性,将其格式化为文本(带有货币符号和所有内容),但在Get方法中将其转换回数字数据类型。
这就是我迄今为止所取得的成就:
public class CurrencyTextBox : TextBox
{
private bool IsValidKey(Key key)
{
int k = (int)key;
return ((k >= 34 && k <= 43) //digits 0 to 9
|| (k >= 74 && k <= 83) //numeric keypad 0 to 9
|| (k == 2) //back space
|| (k == 32) //delete
);
}
private void Format()
{
//formatting decimal to currency text here
//Done! no problems here
}
private void FormatBack()
{
//formatting currency text to decimal here
//Done! no problems here
}
private void ValueChanged(object sender, TextChangedEventArgs e)
{
this.Format();
}
private void MouseClicked(object sender, MouseButtonEventArgs e)
{
this.Format();
// Prevent changing the caret index
this.CaretIndex = this.Text.Length;
e.Handled = true;
}
private void MouseReleased(object sender, MouseButtonEventArgs e)
{
this.Format();
// Prevent changing the caret index
this.CaretIndex = this.Text.Length;
e.Handled = true;
}
private void KeyPressed(object sender, KeyEventArgs e)
{
if (IsValidKey(e.Key))
e.Handled = true;
if (Keyboard.Modifiers != ModifierKeys.None)
return;
this.Format();
}
private void PastingEventHandler(object sender, DataObjectEventArgs e)
{
// Prevent copy/paste
e.CancelCommand();
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
// Disable copy/paste
DataObject.AddCopyingHandler(this, PastingEventHandler);
DataObject.AddPastingHandler(this, PastingEventHandler);
this.CaretIndex = this.Text.Length;
this.PreviewKeyUp += KeyPressed;
this.PreviewMouseDown += MouseClicked;
this.PreviewMouseUp += MouseReleased;
this.TextChanged += ValueChanged;
this.Format();
}
}
公共类CurrencyTextBox:TextBox
{
专用布尔伊斯瓦利德基(密钥)
{
int k=(int)键;
return((k>=34&&k=74&&k看看这篇文章,我想它会对你有所帮助。
或者你可以把这个
private static bool IsTextAllowed(string text)
{
Regex regex = new Regex("[^0-9.-]+"); //regex that matches disallowed text
return !regex.IsMatch(text);
}
在previewtextireput
事件中
private static bool IsTextAllowed(string text)
{
Regex regex = new Regex("[^0-9.-]+"); //regex that matches disallowed text
return !regex.IsMatch(text);
}
e、 Handled=!IsTextAllowed(e.Text)
像这样创建新的依赖项属性
public static readonly DependencyProperty ValueProperty =
DependencyProperty.Register(
"Value",
typeof(decimal?),
typeof(CurrencyTextBox),
new FrameworkPropertyMetadata(
new decimal?(),
FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
new PropertyChangedCallback(ValuePropertyChanged)));
private static void ValuePropertyChanged(
DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
CurrencyTextBox x = (CurrencyTextBox)d;
x.Value = (decimal?)e.NewValue;
}
然后绑定到这个新属性好吧,为了将来的目的,如果有人遇到同样的问题,这里是货币文本框的完整代码。您可以随意使用、修改、出售(千万不要认为它有价值),或者随心所欲地玩它
/*
* the necessary usings:
* using System.Globalization;
* using System.Windows;
* using System.Windows.Controls;
* using System.Windows.Input;
* using System.Threading;
* And don't forget to change the currency settings on the XAML
* or in the defaults (on the contructor)
* It's set by default to Brazilian Real (R$)
*/
public class CurrencyTextBox : TextBox
{
public CurrencyTextBox()
{
CurrencySymbol = "R$ ";
CurrencyDecimalPlaces = 2;
DecimalSeparator = ",";
ThousandSeparator = ".";
Culture = "pt-BR";
}
public string CurrencySymbol { get; set; }
private int CurrencyDecimalPlaces { get; set; }
public string DecimalSeparator { get; set; }
public string ThousandSeparator { get; set; }
public string Culture { get; set; }
private bool IsValidKey(int k)
{
return (k >= 34 && k <= 43) //digits 0 to 9
|| (k >= 74 && k <= 83) //numeric keypad 0 to 9
|| (k == 2) //back space
|| (k == 32) //delete
;
}
private string Format(string text)
{
string unformatedString = text == string.Empty ? "0,00" : text; //Initial state is always string.empty
unformatedString = unformatedString.Replace(CurrencySymbol, ""); //Remove currency symbol from text
unformatedString = unformatedString.Replace(DecimalSeparator, ""); //Remove separators (decimal)
unformatedString = unformatedString.Replace(ThousandSeparator, ""); //Remove separators (thousands)
decimal number = decimal.Parse(unformatedString) / (decimal)Math.Pow(10, CurrencyDecimalPlaces); //The value will have 'x' decimal places, so divide it by 10^x
unformatedString = number.ToString("C", CultureInfo.CreateSpecificCulture(Culture));
return unformatedString;
}
private decimal FormatBack(string text)
{
string unformatedString = text == string.Empty ? "0.00" : text;
unformatedString = unformatedString.Replace(CurrencySymbol, ""); //Remove currency symbol from text
unformatedString = unformatedString.Replace(ThousandSeparator, ""); //Remove separators (thousands);
CultureInfo current = Thread.CurrentThread.CurrentUICulture; //Let's change the culture to avoid "Input string was in an incorrect format"
Thread.CurrentThread.CurrentUICulture = CultureInfo.CreateSpecificCulture(Culture);
decimal returnValue = decimal.Parse(unformatedString);
Thread.CurrentThread.CurrentUICulture = current; //And now change it back, cuz we don't own the world, right?
return returnValue;
}
private void ValueChanged(object sender, TextChangedEventArgs e)
{
// Keep the caret at the end
this.CaretIndex = this.Text.Length;
}
private void MouseClicked(object sender, MouseButtonEventArgs e)
{
// Prevent changing the caret index
e.Handled = true;
this.Focus();
}
private void MouseReleased(object sender, MouseButtonEventArgs e)
{
// Prevent changing the caret index
e.Handled = true;
this.Focus();
}
private void KeyReleased(object sender, KeyEventArgs e)
{
this.Text = Format(this.Text);
this.Value = FormatBack(this.Text);
}
private void KeyPressed(object sender, KeyEventArgs e)
{
if (IsValidKey((int)e.Key))
return;
e.Handled = true;
this.CaretIndex = this.Text.Length;
}
private void PastingEventHandler(object sender, DataObjectEventArgs e)
{
// Prevent/disable paste
e.CancelCommand();
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
DataObject.AddCopyingHandler(this, PastingEventHandler);
DataObject.AddPastingHandler(this, PastingEventHandler);
this.CaretIndex = this.Text.Length;
this.KeyDown += KeyPressed;
this.KeyUp += KeyReleased;
this.PreviewMouseDown += MouseClicked;
this.PreviewMouseUp += MouseReleased;
this.TextChanged += ValueChanged;
this.Text = Format(string.Empty);
}
public decimal? Value
{
get { return (decimal?)this.GetValue(ValueProperty); }
set { this.SetValue(ValueProperty, value); }
}
public static readonly DependencyProperty ValueProperty = DependencyProperty.Register(
"Value",
typeof(decimal?),
typeof(CurrencyTextBox),
new FrameworkPropertyMetadata(new decimal?(), FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, new PropertyChangedCallback(ValuePropertyChanged)));
private static void ValuePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((CurrencyTextBox)d).Value = ((CurrencyTextBox)d).FormatBack(e.NewValue.ToString());
}
}
/*
*必要的使用:
*利用制度全球化;
*使用System.Windows;
*使用System.Windows.Controls;
*使用System.Windows.Input;
*使用系统线程;
*别忘了更改XAML上的货币设置
*或在默认情况下(在构造函数上)
*默认设置为巴西雷亚尔(R$)
*/
公共类CurrencyTextBox:TextBox
{
公共货币文本框()
{
CurrencySymbol=“R$”;
CurrencyDecimalPlaces=2;
小数分隔符=“,”;
千分位分隔符=“.”;
Culture=“pt BR”;
}
公共字符串CurrencySymbol{get;set;}
私有int CurrencyDecimalPlaces{get;set;}
公共字符串小数分隔符{get;set;}
公共字符串千位分隔符{get;set;}
公共字符串区域性{get;set;}
二等兵布尔·伊斯瓦利德基(内特k)
{
return(k>=34&&k=74&&k我认为这实际上是不可能的,除了一个只允许数字的框的简单情况。理想情况下,您希望框只能包含一个有效条目,但小数包含一些字符(如“-”和“.”)它们本身无效。用户无法在不将框置于无效状态的情况下键入“-”
类似地,他们可以输入“1”,然后删除1并使框处于不确定状态。当然,这会导致验证错误和红色边框,但您的视图模型仍然认为该值为1,并且不知道该问题
对于正整数,您只能允许数字,并在为空时自动插入零(尽管这有点不友好)
对于小数和负整数,我认为最好的方法是约束用户可以键入的键,但您仍然需要将number属性包装成字符串并进行验证—无论是在按下OK按钮时,还是在理想情况下实现INotifyDataError以显示错误并禁用OK按钮。我想让用户输入任何文本即使是字符串,当失去焦点时,如果他没有添加十进制值,则调用。我想问题不清楚。问题在于绑定,而不是格式化逻辑。格式化文本已经可以了…如果是这种情况,请创建新的依赖属性
调用它的值并将您的货币绑定到它。这解决了问题。在ValuePropertyChanged()中我已经用FormatBack和voilá设置了Value属性!竖起大拇指!你不能投票,因为我的“新手”名声!哇,这真的很有帮助!我这里还有另一个问题:当我把这个控件放到我的WPF UI上时,我绑定的初始值在我明确告诉控件更新之前不会显示。有没有办法在y中实现它我们的代码?编辑:我在值的Setter中添加了以下内容:如果(!this.IsFocused)this.Text=String.Format(“{0:0.00}”,Value)
为什么要添加事件处理程序而不是只覆盖基处理程序?为什么不“private void keyreased(object sender,KeyEventArgs e)”,为什么不“protected override void OnKeyUp”(KeyEventArgs e)“?
<myNamespace:CurrencyTextBox
Value="{Binding Path=DataContext.MyDecimalProperty, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"
CurrencySymbol="R$ "
Culture="pt-BR"
CurrencyDecimalPlaces="2"
DecimalSeparator=","
ThousandSeparator="." />