TextBox.BeforeTextChanging 事件

定义

当文本框中的文本开始更改时,但在 更新 Text 属性之前同步发生。

// Register
event_token BeforeTextChanging(TypedEventHandler<TextBox, TextBoxBeforeTextChangingEventArgs const&> const& handler) const;

// Revoke with event_token
void BeforeTextChanging(event_token const* cookie) const;

// Revoke with event_revoker
TextBox::BeforeTextChanging_revoker BeforeTextChanging(auto_revoke_t, TypedEventHandler<TextBox, TextBoxBeforeTextChangingEventArgs const&> const& handler) const;
public event TypedEventHandler<TextBox,TextBoxBeforeTextChangingEventArgs> BeforeTextChanging;
function onBeforeTextChanging(eventArgs) { /* Your code */ }
textBox.addEventListener("beforetextchanging", onBeforeTextChanging);
textBox.removeEventListener("beforetextchanging", onBeforeTextChanging);
- or -
textBox.onbeforetextchanging = onBeforeTextChanging;
Public Custom Event BeforeTextChanging As TypedEventHandler(Of TextBox, TextBoxBeforeTextChangingEventArgs) 
<TextBox BeforeTextChanging="eventhandler"/>

事件类型

适用于

另请参阅