C#

public void SomeOperation()
{
    try
    {
        SomeOperationBase();
    }
    catch(Exception)
    {
        // Recover your data here.
        // You can throw your own exception here (don't forget to set InnerException for it).
        // Or you can simply rethrow exception.
        throw;
    }
}

protected virtual void SomeOperationBase()
{
    // Your code for SomeOperation() here.
}

The unfortunate side effect is: it seems there are no simple way to have all user code run at the begining or at the end of the code.

void ActionImpl() { /* ... */ }

protected void Action(TextElement aParent)
{
   foreach(TextElement child in this)
       child.Action(); // exception might happen in child too
   ActionImpl();
   NotifyAction(this); // <= potential user exception here
}
protected virtual void NotifyAction(TextElement aParent)
{
   // nothing, up to the subclass
   // the subclass might throw an exception
}

protected void BigAction()
{
    Action_1(); // subclass exception might happen here
    Action_2(); // subclass exception might happen here too
}

private void FillListBox()
{
    foreach (TreeNode rootNode in treeView.Nodes)
    {
        AddSubtree(rootNode, string.Empty);
    }
}
<p/>
private void AddSubtree(TreeNode node, string prefix)
{
    listBox.Items.Add(prefix + node.Text);
    prefix += '>';

    foreach (TreeNode childNode in node.Nodes)
    {
        AddSubtree(childNode, prefix);
    }
}

while (dbReader.Read())
{
    TreeNode newNode = new TreeNode((string)dbReader["Title"]);
    newNode.Tag = (string)dbReader["PARENT_CAT_ID"];
    newNode.Name = (string)dbReader["CAT_ID"];
    treeView.Nodes.Add(newNode);
}

for (int j = treeView.Nodes.Count - 1; j >= 0; j--)
{
    TreeNode node = treeView.Nodes[j];
    string parentId = (string)node.Tag;
    if (parentId != "0")
    {
        TreeNode[] parent = treeView1.Nodes.Find(parentId, true);
        if (parent.Length == 1)
        {
            treeView.Nodes.Remove(node);
            parent[0].Nodes.Add(node);
        }
    }
}

if(e.KeyCode == (Keys.A | Keys.Control))

Tech, life, family, faith: Give me a visit.
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The apostle Paul, modernly speaking: Epistles of Paul

Judah Himango

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Goof around music jam with my brothers (with video)
The apostle Paul, modernly speaking: Epistles of Paul

Judah Himango

picasso2 wrote:

When I run the application, one of the textBox has the focus.

picasso2 wrote:

do you have a sample code to override using ProcessCmdKey?

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (keyData == (Keys.Control | Keys.A))
    {
       MessageBox.Show("You pressed CTRL+A!");
    }
    return base.ProcessCmdKey(ref msg, keyData);
}

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Goof around music jam with my brothers (with video)
The apostle Paul, modernly speaking: Epistles of Paul

Judah Himango

MyForm.KeyPreview = true;
MyForm.KeyDown += new KeyEventHandler(MyForm_KeyDown);
.
.
.
private void MyForm_KeyDown(object sender, KeyEventArgs e)
{
    if ((e.KeyCode == Keys.A) && e.Control && !e.Alt)
    {
        Debug.WriteLine("Ctrl + A");
    }
}