如何取消选择/空白数据绑定的组合框？ SelectedIndex = -1不起作用 [英] How to deleselect / blank a databound ComboBox? SelectedIndex = -1 does not work

问题描述

我试图在Windows窗体应用程序中取消选择（空白显示）多个组合框。在我的应用程序中，我有一个Reset方法，该方法将每个组合的SelectedIndex设置为-1。我所有的组合框都是数据绑定的，即每个组合框都是使用数据源填充的。

I am trying to deselect (blank out) a number of combo-boxes in my windows forms application. In my application I have a Reset method that sets the SelectedIndex for each combo to -1. All of my combo-boxes are databound, i.e. each combo-box is populated using a datasource.

我注意到有时我的Reset方法有效，即取消选择当前选中的项目，然后使组合变为空白。但是，有时我会在尝试将其设置为-1之后立即选择第一个项目（SelectedIndex = 0）。从用户的角度来看，这似乎是一个错误，因为它并不总是清除表单。

I have noticed that sometimes my Reset method works, i.e. it deselects the currently selected item and blanks the combo. However, other times it chooses the first item (SelectedIndex = 0) straight after I attempt to set it to -1. From a users point of view this looks like a bug as it doesn't always "clear" the form.

根据MSDN：

要取消选择当前选定的项目，请将SelectedIndex设置为-1。如果该项是数据绑定项，则不能将ComboBox项的SelectedIndex设置为-1。

"To deselect the currently selected item, set the SelectedIndex to -1. You cannot set the SelectedIndex of a ComboBox item to -1 if the item is a data-bound item."

有人知道解决方法吗？

非常感谢

推荐答案

使用void和property的组合

Use combination of the void and property

comboBox.ResetText();

 //to reset selected value
comboBox.SelectedIndex = -1;

这篇关于如何取消选择/空白数据绑定的组合框？ SelectedIndex = -1不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！