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

问题描述

我试图在我的 Windows 窗体应用程序中取消选择(消隐)一些组合框.在我的应用程序中，我有一个 Reset 方法，它将每个组合的 SelectedIndex 设置为 -1.我所有的组合框都是数据绑定的，即每个组合框都使用数据源填充.

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 方法会起作用，即它取消选择当前选定的项目并清除组合.但是，有时它会在我尝试将其设置为 -1 后直接选择第一项(SelectedIndex = 0).从用户的角度来看，这看起来像是一个错误，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.如果该项目是数据绑定项目，则不能将 ComboBox 项目的 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;

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