的BindingList ListChanged事件不触发，直到填满数据？ [英] BindingList ListChanged event not firing until filled with data?

问题描述

我在写code，最终从远程数据库提取数据到使用数据绑定一个DataGridView。我目前正在创建code使用CSV文件和的BindingList作为测试工作。

I'm writing code to eventually pull data from a remote database into a DataGridView using a databinding. I am currently creating the code to work with a CSV file and a BindingList as a test.

我希望我的窗体上的显示屏，显示最后一次数据库更新。我目前使用我的BindingList的ListChanged事件来更新最后数据库更新显示。

I want a display on my form that shows the last time the database was updated. I'm currently using the ListChanged event on my BindingList to update the "last database update" display.

在ListChanged事件似乎如果它钩住了最初填充数据库之后才能发射。下面是从我班的一些code扩展DataGridView的：

The ListChanged event seems to only be firing if it's hooked up after the database is initially populated. Here's some code from my class that extends DataGridView:

BindingList<CsvTest> Data = new BindingList<CsvTest>;

public void InitGrid()
{
    // Data.ListChanged += Data_ListChanged;  // Event never fires if this is here!
    Data = CsvTest.ParseCsv("test.csv");
    Data.ListChanged += Data_ListChanged;     // Working when it's here!
    this.DataSource = Data; // DataGridView DataSource
}

我想为我的延迟更新为最初填充列表。任何人都可以想到的任何理由，这是不工作？

I would like for my delay to update as the list is initially populated. Can anyone think of any reason why this isn't working?

非常感谢。

推荐答案

行

Data = CsvTest.ParseCsv("test.csv");

将覆盖你的内容数据变量。那是以前设置的任何值（例如 Data.ListChanged ）将属于旧的BindingList 对象。而新的的BindingList 对象不具有价值，直到你把它。

will overwrite the content of you Data variable. Any value that was set before (for example Data.ListChanged) will belong to the old BindingList object. And your new BindingList object does not have the value, until you set it.

如果您想设置之前 ParseCsv 的价值，你将不得不清除的BindingList 在数据，然后从 ParseCsv 。

If you would like to set the value before ParseCsv, you will have to clear the BindingList in Data and then add all items from ParseCsv.

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