ComboBox.ValueMember 和 DisplayMember [英] ComboBox.ValueMember and DisplayMember

问题描述

我如何设置这些值?我有一个包含要在组合框中设置的所有数据的数据表，但我找不到如何设置它.

How do i set this values? I have a DataTable with all the data i want to set in the combobox, but i cant find how to set it.

我试过了

ComboBox1.DataSource = dataTable;
ComboBox1.ValueMember = "id"; // --> once hes here, he just jumps out the method
ComboBox1.DisplayMember = "name";

没有编译错误，警告，什么都没有..只是跳出来了！

No compilation error, warning, nothing.. just jumps out!

这是填充DataTable的查询

This is the query to fill the DataTable

"Select * from "Table""

我检查了调试器，数据表已填满.列名称是id"和name".组合框为空.我是第一次填写！

I checked with the debugger and the datatable was filled. The columns names are "id" and "name". ComboBox is blank. I'm filling it for the first time!

推荐答案

你不应该按照这个顺序设置你的列表框和/或组合框的datasource

You should not set datasource of your listbox and/or combobox in this order

ComboBox1.DataSource = dataTable;

ComboBox1.ValueMember = "id"; 

ComboBox1.DisplayMember = "name";

相反，这是正确的顺序:

ComboBox1.ValueMember = "id"; 

ComboBox1.DisplayMember = "name";

ComboBox1.DataSource = dataTable;

注意:设置datasource应该在最后一行.

NOTE: setting datasource should be last line.

如果您先设置 datasource，SelectedIndexChanged 事件将触发，您可能会收到转换错误或其他异常.

If you set datasource first, SelectedIndexChanged event will fire and you may get the cast error or other exception.

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