String Replicate

February 3, 2009

The simplest way to replicate (repeat) a string in C# is using string class constructor:
string s = new string(‘#’, 4); //result: ####

If you want to replicate a sub-string (not only a char), use this:
string.Concat(System.Collections.ArrayList.Repeat(“##”,4).ToArray());


DataBound ComboBox Problem

February 3, 2009

Problem:
When you want to use a data bound ComboBox in .NET (C#, VB, etc), you should set a few properties such as DataSource, DisplayMember and ValueMember.
It works fine unless you want to set SelectedValue for the first time. It won’t be set.

Solution:
I found that BindingContext property must be used before initializing SelectedValue:

ComboBox1.BindingContext = new BindingContext();
ComboBox1.DataSource = MyDataSet.DefaultView
ComboBox1.DisplayMember = “Title”;
ComboBox1.ValueMember = “Code”;
ComboBox1.SelectedValue = 1;