wpf 修改输入框 光标_在WPF C#中将光标焦点设置为可编辑组合框

I have editable combobox in WPF and I want to set focus from C#,

I am using Combobox.Focus(), but it shows only selection but I want edit option where user can start entering.

Update : Figured out FIX

I ended up adding 'Loaded' Event to the Combobox and Wrote following Code to get focus in and it worked Fine

private void LocationComboBox_Loaded(object sender, RoutedEventArgs e)

{

ComboBox cmBox = (System.Windows.Controls.ComboBox)sender;

var textBox = (cmBox.Template.FindName("PART_EditableTextBox",

cmBox) as TextBox);

if (textBox != null)

{

textBox.Focus();

textBox.SelectionStart = textBox.Text.Length;

}

}

Talk1:

Why wouldn't it work if I write the same code somewhere else? (Say, in a button's click handler?)

Solutions1

Try Creating a Focus Extension like below, and set the attached property to the text box and bind it.

public static class FocusExtension

{

public static bool GetIsFocused(DependencyObject obj)

{

return (bool)obj.GetValue(IsFocusedProperty);

}

public static void SetIsFocused(DependencyObject obj, bool value)

{

obj.SetValue(IsFocusedProperty, value);

}

public static readonly DependencyProperty IsFocusedProperty =

DependencyProperty.RegisterAttached(

"IsFocused", typeof(bool), typeof(FocusExtension),

new UIPropertyMetadata(false, OnIsFocusedPropertyChanged));

private static void OnIsFocusedPropertyChanged(DependencyObject d,

DependencyPropertyChangedEventArgs e)

{

var uie = (UIElement)d;

if ((bool)e.NewValue)

{

OnLostFocus(uie, null);

uie.Focus();

}

}

private static void OnLostFocus(object sender, RoutedEventArgs e)

{

if (sender != null && sender is UIElement)

{

(sender as UIElement).SetValue(IsFocusedProperty, false);

}

}

}

XAML

Talk1:

I don't have TextBox under Combobox as Custom Template, I have editable combobox. Still I can use this?

Talk2:

yes you can use it for any control as its an Attached property.

Talk3:

Is the OnLostFocus required there? I don't understand, can you explain?

Solutions2

If I understand you correctly, you have following situation: you set focus to ComboBox and observe selected text inside editable area, but you want it to be empty with only blinking caret inside. If so, you can do it this way:

ComboBox.Focus();

ComboBox.Text = String.Empty;

Solutions3

Have a look at this. It might help you