如何解决WPF / C#文本框中的数字是动态计算的
|| 好的,因此,我可以肯定我在使用此小型应用程序的过程中步入正轨,但请告诉我。用户在4个可编辑文本框中输入4个数字中的3个,然后自动计算缺少的数字。此处的应用图片: http://www.peauproductions.com/images/lens_app.PNG 我研究了数据绑定,我认为我需要使值能够全局更改。我希望这些值能够动态更新/计算,而不必具有“计算”按钮。 一旦开始运行,我需要执行验证检查以确保仅输入布尔值(无文本),并弹出工具提示说要输入数字。 立即获得以下错误: \“ \'设置属性\'System.Windows.Controls.TextBox.Text \'引发异常。\'行号\ '56 \'和行位置\ '51 \'。\” MainWindow.xaml代码:<Window x:Class=\"ConverterApp.MainWindow\"
xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\"
xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\"
Title=\"ConverterApp\" Height=\"360\" Width=\"280\"
xmlns:c=\"clr-namespace:ConvertorApp;assembly=\">
<Grid>
<!--Outer Box + Title-->
<TextBox Height=\"309\" Width=\"248\"
Text=\" Lens Calculator\"
IsReadOnly=\"True\"
Margin=\"5,5,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
BorderThickness=\"2.0\"
FontSize=\"16\" FontFamily=\"Verdana\" FontWeight=\"Bold\">
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint=\"0,0\" EndPoint=\"1,1\" >
<GradientStop Color=\"Black\" Offset=\"0\" />
</LinearGradientBrush>
</TextBox.BorderBrush>
</TextBox>
<!--Title Text-->
<TextBox Height=\"50\" Width=\"230\"
Text=\"Enter Image Width,Length and Either Distance or Lens Values Below\"
IsReadOnly=\"True\"
Margin=\"14,29,0\"
TextWrapping=\"Wrap\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontSize=\"12\" FontFamily=\"Verdana\" FontStyle=\"Italic\"
BorderThickness=\"0\">
</TextBox>
<TextBox Height=\"20\" Width=\"230\"
Text=\"Must Be Same Units (in,ft,cm,mm)\"
IsReadOnly=\"True\"
Margin=\"14,59,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontSize=\"10\" FontFamily=\"Verdana\" FontStyle=\"Italic\"
BorderThickness=\"0\">
</TextBox>
<!--Distance-->
<TextBox Height=\"20\" Width=\"105\"
Text=\"Distance/Height:\"
IsReadOnly=\"True\"
Margin=\"15,80,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\"
BorderThickness=\"0\">
</TextBox>
<TextBox x:Name=\"DistanceBox\" Height=\"20\" Width=\"50\"
Text=\"{x:Static c:Variables.DistanceBox}\"
Margin=\"125,0\"
MaxLength=\"5\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\">
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint=\"0,1\" >
<GradientStop Color=\"Black\" Offset=\"0\" />
</LinearGradientBrush>
</TextBox.BorderBrush>
</TextBox>
<!--Image Width-->
<TextBox Height=\"20\" Width=\"90\"
Text=\"Image Width:\"
IsReadOnly=\"True\"
Margin=\"15,105,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\"
BorderThickness=\"0\">
</TextBox>
<TextBox x:Name=\"WidthBox\" Height=\"20\" Width=\"50\"
Text=\"{x:Static c:Variables.WidthBox}\"
Margin=\"125,0\"
MaxLength=\"5\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\">
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint=\"0,1\" >
<GradientStop Color=\"Black\" Offset=\"0\" />
</LinearGradientBrush>
</TextBox.BorderBrush>
</TextBox>
<!--Image Length-->
<TextBox Width=\"95\"
Text=\"Image Length:\"
IsReadOnly=\"True\"
Margin=\"15,130,161\" HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\"
BorderThickness=\"0\">
</TextBox>
<TextBox x:Name=\"LengthBox\" Height=\"20\" Width=\"50\"
Text=\"{x:Static c:Variables.LengthBox}\"
Margin=\"125,0\"
MaxLength=\"5\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\">
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint=\"0,1\" >
<GradientStop Color=\"Black\" Offset=\"0\" />
</LinearGradientBrush>
</TextBox.BorderBrush>
</TextBox>
<!--Lens Needed-->
<TextBox Height=\"20\" Width=\"90\"
Text=\"Lens (mm):\"
IsReadOnly=\"True\"
Margin=\"15,155,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\"
BorderThickness=\"0\">
</TextBox>
<TextBox x:Name=\"LensNeeded\" Height=\"20\" Width=\"50\"
Text=\"{x:Static c:Variables.LensNeeded}\"
Margin=\"125,0\"
MaxLength=\"4\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\">
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint=\"0,1\" >
<GradientStop Color=\"Black\" Offset=\"0\" />
</LinearGradientBrush>
</TextBox.BorderBrush>
</TextBox>
<!--Info-->
<TextBox Height=\"70\" Width=\"230\"
Text=\"The lens focal length value represents the estimated mm value for a 1/4 inch sensor (Playstation Eye). A lower mm will give a wider Field of View (FOV),and a higher value less FOV. \"
IsReadOnly=\"True\"
TextWrapping=\"Wrap\"
Margin=\"15,180,0\"
FontSize=\"11\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\" FontStyle=\"Italic\"
BorderThickness=\"0\">
</TextBox>
<TextBox Height=\"55\" Width=\"230\"
Text=\"It is not recommend you use a lens of less than 2.5mm focal length with image tracking software due to distortion.\"
IsReadOnly=\"True\"
FontSize=\"11\"
TextWrapping=\"Wrap\"
Margin=\"15,253,0\"
VerticalAlignment=\"Top\"
HorizontalAlignment=\"Left\"
FontFamily=\"Verdana\" FontStyle=\"Italic\"
BorderThickness=\"0\">
</TextBox>
</Grid>
MainWindow.xaml.cs代码:
using System;
using System.Windows;
namespace ConvertorApp
{
public class Variables
{
public const double DistanceBox = 0;
public const double WidthBox = 0;
public const double LengthBox = 0;
public const double LensNeeded = 0;
public const double WidthBased = 0;
public const double LengthBased = 0;
public void Calc()
{
double WidthBased = 2.952*(DistanceBox/WidthBox);
double LengthBased = 3.984*(DistanceBox/LengthBox);
if (WidthBased < LengthBased)
{
double LensNeeded = WidthBased;
}else{
double LensNeeded = LengthBased;
}
}
}
}
如果您可以想到一种更简单或更正确的方法来进行自己的工作,请告诉我(我刚刚开始学习WPF / C#内容)。谢谢
更新:
这是显示从下面建议的更改的后台代码:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.ComponentModel;
namespace ConverterApp
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new Variables();
}
}
public class Variables : INotifyPropertyChanged
{
// Declare the PropertyChanged event.
public event PropertyChangedEventHandler PropertyChanged;
private double m_distanceBox;
public double DistanceBox
{
get { return m_distanceBox; }
set
{
m_distanceBox = value;
// modify calc to read the text values
Calc();
// Call NotifyPropertyChanged when the source property
// is updated.
NotifyPropertyChanged(\"DistanceBox\");
}
}
private double m_widthBox;
public double WidthBox
{
get { return m_widthBox; }
set
{
m_widthBox = value;
// modify calc to read the text values
Calc();
// Call NotifyPropertyChanged when the source property
// is updated.
NotifyPropertyChanged(\"WidthBox\");
}
}
private double m_lengthBox;
public double LengthBox
{
get { return m_lengthBox; }
set
{
m_lengthBox = value;
// modify calc to read the text values
Calc();
// Call NotifyPropertyChanged when the source property
// is updated.
NotifyPropertyChanged(\"LengthBox\");
}
}
private double m_lensBox;
public double LensNeeded
{
get { return m_lensBox; }
set
{
m_lensBox = value;
// modify calc to read the text values
Calc();
// Call NotifyPropertyChanged when the source property
// is updated.
NotifyPropertyChanged(\"LensNeeded\");
}
}
public void Calc()
{
double WidthBased = 2.95 * (DistanceBox / WidthBox);
double LengthBased = 3.98 * (DistanceBox / LengthBox);
if (WidthBased < LengthBased)
{
LensNeeded = Math.Round(WidthBased,2);
}else{
LensNeeded = Math.Round(LengthBased,2);
}
}
// NotifyPropertyChanged will raise the PropertyChanged event,// passing the source property that is being updated.
public void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this,new PropertyChangedEventArgs(propertyName));
}
}
}
}
**错误我现在正在获取double函数中的get {}上的StackOverflowException。有任何想法吗?
解决方法
抛出异常是因为该行
Text=\"{x:Static c:Variables.DistanceBox}\"
实际上是这样的
textBox.Text = Variables.DistanceBox;
这不会在C#中编译。在XAML中,它引发异常。相反,您应该从字段中创建属性:
public double DistanceBox { get; set; }
并通过添加将Variables
设置为窗口的DataContext
DataContext = new Variables();
到窗口的构造函数(或Loaded
事件的处理函数)。
然后,您在XAML中使用绑定(该绑定使用转换器在ѭ11中产生ѭ10):
Text=\"{Binding DistanceBox}\"
要在值更改时调用Calc()
,可以将属性更改为
private double m_distanceBox;
public double DistanceBox
{
get { return m_distanceBox; }
set
{
m_distanceBox = value;
Calc();
}
}
为确保在文本框中反映出Variables
中的更改,您应实现INotifyPropertyChanged
界面。
编辑:#17ѭ的C#代码:
public partial class MainWindow
{
public MainWindw()
{
InitializeComponent();
DataContext = new Variables();
}
}
, 您要设定文字吗?在wpf中,您需要使用设置直接文本属性的insert方法。
, 您在设置文本值时犯了错误:
YourTextBox.Text=YourValue;
在您的情况下:
LensNeeded.Text = WidthBased.ToString();
, 您应该为文本框使用数据绑定。
修改您的Variables类以将这4个值作为字符串属性公开(您不能将数据绑定到字段,而只能绑定到属性):
public class Variables
{
// code as in your example
public string LensValueNeeded
{
get { return LensNeeded.ToString(); }
set { Calc(); } // modify calc to read the text values
}
/// same for the other 3 values
}
当数据绑定设置为双向时,请确保修改Calc方法以从TextBox中读取当前值。您将需要使用double.Parse()方法将字符串值转换回double值:
double d = double.Parse(stringValue);
将网格的DataContext设置为Variables类的实例
将您的TextBox的文本绑定到string属性:
Text = {Binding LensNeededValue}
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