C# 数值更改时NumericUpDown数据绑定属性不更新

C# 数值更改时NumericUpDown数据绑定属性不更新,c#,winforms,C#,Winforms,我正在尝试对NumericUpDown WinForm控件执行数据绑定。按照设计执行绑定工作,但我遇到一个问题,在元素失去焦点之前,值不会被推送到绑定属性。当控件中的值更改而不需要丢失焦点时,我是否缺少一些东西来更新属性 如果按设计工作,是否有办法在不失去焦点的情况下强制更新属性 逻辑: using System; using System.Windows.Forms; public partial class Form1 : Form { private NumericUpDown

我正在尝试对NumericUpDown WinForm控件执行数据绑定。按照设计执行绑定工作,但我遇到一个问题,在元素失去焦点之前,值不会被推送到绑定属性。当控件中的值更改而不需要丢失焦点时,我是否缺少一些东西来更新属性

如果按设计工作,是否有办法在不失去焦点的情况下强制更新属性

逻辑:

using System;
using System.Windows.Forms;

public partial class Form1 : Form
{
    private NumericUpDown numericUpDown1 = new NumericUpDown();
    private ExampleData _ed = new ExampleData();

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        // Define the UI Control
        numericUpDown1.DecimalPlaces = 7;
        numericUpDown1.Location = new System.Drawing.Point(31, 33);
        numericUpDown1.Name = "numericUpDown1";
        numericUpDown1.Size = new System.Drawing.Size(120, 20);
        numericUpDown1.TabIndex = 0;

        // Add the UI Control
        Controls.Add(numericUpDown1);

        // Bind the property to the UI Control
        numericUpDown1.DataBindings.Add("Value", _ed, nameof(_ed.SampleDecimal));

        numericUpDown1.ValueChanged += NumericUpDown1_ValueChanged;
    }

    private void NumericUpDown1_ValueChanged(object sender, EventArgs e)
    {
        // This will fire as you change the control without losing focus.
        System.Diagnostics.Debugger.Break();
    }
}

public class ExampleData
{
    public decimal SampleDecimal
    {
        get { return _sampleDecimal; }
        set
        {
            // This set isn't called until after you lose focus of the control.
            System.Diagnostics.Debugger.Break();
            _sampleDecimal = value;
        }
    }

    private decimal _sampleDecimal = 1.0m;
}

将您的绑定更改为:

numericUpDown1.DataBindings.Add(nameof(NumericUpDown.Value), _ed, nameof(ExampleData.SampleDecimal), false, DataSourceUpdateMode.OnPropertyChanged);
这将确保绑定在值更改时触发,而不是在将焦点从控件移开时触发

如果您希望能够从代码更新SampleDecimal并在numericupdown上更新它,则需要在SampleData类上实现INotifyPropertyChanged接口,如下所示:

public class ExampleData : INotifyPropertyChanged
{

    protected void OnPropertyChanged([CallerMemberName] string propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public event PropertyChangedEventHandler PropertyChanged;

    public decimal SampleDecimal
    {
        get { return _sampleDecimal; }
        set
        {
            _sampleDecimal = value;
            OnPropertyChanged();
        }
    }

    private decimal _sampleDecimal = 1.0m;
}

这么简单的事情,唉。。。谢谢你的帮助!