我有一些控件,它们不会更新它们绑定的对象的各自属性,直到焦点丢失。有类似的问题,接受的答案引用了DataSourceUpdateMode.OnPropertyChange
被声明,我就是这样做的,但这种行为仍然存在。下面是一个示例实现。我会尽量做到彻底,但又要简洁。MyConfig
类是通过我称为Configuration
的单例类中的属性来访问的。
[Serializable]
public class MyConfig : INotifyPropertyChanged
{
public enum MyEnum
{
Foo,
Bar
}
public MyConfig()
{
MyProperty = MyEnum.Foo;
}
private MyEnum _MyProperty;
public MyEnum MyProperty
{
get { return _MyProperty; }
set { if (value != _MyProperty) { _MyProperty = value; OnPropertyChanged("MyProperty"); } }
}
[field: NonSerialized]
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (string.IsNullOrEmpty(propertyName))
throw new ArgumentNullException(propertyName);
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public partial class ConfigForm : Form
{
public ConfigForm()
{
InitializeComponent();
MyComboBox.Items.AddRange(Enum.GetNames(typeof(MyConfig.MyEnum)));
}
private void ConfigForm_Load(object sender, EventArgs e)
{
MyComboBox.DataSource = Enum.GetValues(typeof(MyConfig.MyEnum));
MyComboBox.DataBindings.Add("SelectedItem", Configuration.Instance.MyConfig, "MyProperty", false, DataSourceUpdateMode.OnPropertyChanged);
}
}
考虑到下面的简短实现,我不确定我可以忽略什么来确保立即进行属性更改。我可以更改,在本例中,在ComboBox中从Foo
更改为Bar
,但除非从ComboBox中移除焦点,否则什么都不会更改。有谁有什么想法吗?
发布于 2011-12-06 05:26:29
关于OnPropertyChanged
,WinForms ComboBox
是不可靠的。下面是一个旧项目中的一些代码,我用它来让OnPropertyChanged
按照我期望的SelectedItem
属性的方式工作。这适用于我的特定实例,但有时我通常很难让这个场景正常工作。祝好运!
/// <summary>
/// A modification of the standard <see cref="ComboBox"/> in which a data binding
/// on the SelectedItem property with the update mode set to DataSourceUpdateMode.OnPropertyChanged
/// actually updates when a selection is made in the combobox.
/// </summary>
public class BindableComboBox : ComboBox
{
/// <summary>
/// Raises the <see cref="E:System.Windows.Forms.ComboBox.SelectionChangeCommitted"/> event.
/// </summary>
/// <param name="e">An <see cref="T:System.EventArgs"/> that contains the event data.</param>
protected override void OnSelectionChangeCommitted(EventArgs e)
{
base.OnSelectionChangeCommitted(e);
var bindings = this.DataBindings
.Cast<Binding>()
.Where(x =>
x.PropertyName == "SelectedItem" &&
x.DataSourceUpdateMode == DataSourceUpdateMode.OnPropertyChanged);
foreach (var binding in bindings)
{
// Force the binding to update from the new SelectedItem
binding.WriteValue();
// Force the Textbox to update from the binding
binding.ReadValue();
}
}
}
https://stackoverflow.com/questions/8392019
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