[英]Dynamically created elements' event handler
I'm working on a Windows Phone 7.1 (7.5) app. 我正在开发Windows Phone 7.1(7.5)应用程序。 The idea: app gets an list of data from server, creates a TextBlock for each of them and applies Tap event handler for each of them.
想法:app从服务器获取数据列表,为每个数据创建一个TextBlock,并为每个数据应用Tap事件处理程序。 The problem: since I can only use one handler for all of the elements, how to identify the sender?
问题:因为我只能为所有元素使用一个处理程序,如何识别发件人?
The part for creating a new TextBlock: (note: itemsAdded is an outside variable, that is to set proper margins) 用于创建新TextBlock的部分:(注意:itemsAdded是一个外部变量,即设置适当的边距)
void addInfoItem(string text)
{
Thickness tempThick = fatherText.Margin;
tempThick.Top += itemsAdded * 58;
itemsAdded++;
TextBlock temp = new TextBlock() { Text = text, FontSize = 40, HorizontalAlignment = HorizontalAlignment.Left, VerticalAlignment = VerticalAlignment.Top, Margin = tempThick };
temp.Tap += whenTapped;
ContentPanel.Children.Add(temp);
}
whanTapped event handler: whanTapped事件处理程序:
private void whenTapped(object sender, RoutedEventArgs e)
{
//how to identify the sender?
}
When debugging, "object sender" gives enough info to identify the sender - "Text" property of the TextBlock, but during coding, all i get from "object sender" is the following: Equals, GetHashCode, GetType, ToString. 在调试时,“对象发送者”提供了足够的信息来识别发送者 - TextBlock的“Text”属性,但在编码期间,我从“对象发送者”获得的是以下内容:Equals,GetHashCode,GetType,ToString。 (ToString only tells that this is generally a TextBlock, that's all).
(ToString只告诉它通常是一个TextBlock,就是全部)。
but during coding, all i get from "object sender" is the following:
但在编码过程中,我从“对象发送者”获得的是以下内容:
Equals, GetHashCode,GetType, ToString.Equals,GetHashCode,GetType,ToString。
because Object
only supports those methods and it is the parent class of all (almost). 因为
Object
只支持那些方法,它是所有(几乎)的父类。 and parent class can contain/hold the child class memebrs but you can't access the child members untill unless you cast them to the child type. 和父类可以包含/保持子类memebrs,但除非将它们转换为子类型,否则不能访问子成员。
so you use can sender
object but you need to cast it to your control TextBlock
to get the required members to invoke. 因此,您使用can
sender
对象,但需要将其TextBlock
转换为控件TextBlock
以获取所需的成员调用。
TextBlock temp = (TextBlock) sender;
temp.Invi=okeSomething(); //now you can invoke `TextBlock` memebrs
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