Generic event procedure for mutiple controls.
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I want to be able to create generic event procedures that can be used for a number of controls (the same type) on a form. For example (assume the object sender would always be a text box);
private void tbCallBlockPct_Click(object sender, EventArgs e) { sender.SelectAll(); }However when I try somehting like this I get a syntax error that the “object sender does not contain a definition for SelectAll”. If the function is being passed a textbox as the variable sender should not all of its methods and properties be accessable?David Wilkes
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I want to be able to create generic event procedures that can be used for a number of controls (the same type) on a form. For example (assume the object sender would always be a text box);
private void tbCallBlockPct_Click(object sender, EventArgs e) { sender.SelectAll(); }However when I try somehting like this I get a syntax error that the “object sender does not contain a definition for SelectAll”. If the function is being passed a textbox as the variable sender should not all of its methods and properties be accessable?David Wilkes
senderis of typeobject, which doesn't have aSelectAll()method in its interface. You should castsenderto an object variable of typeTextBoxin order to invoke properties/methods particular to this class.TextBox tb = (TextBox)sender;
tb.SelectAll();Paul Marfleet
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senderis of typeobject, which doesn't have aSelectAll()method in its interface. You should castsenderto an object variable of typeTextBoxin order to invoke properties/methods particular to this class.TextBox tb = (TextBox)sender;
tb.SelectAll();Paul Marfleet
Thanks. That is alomost exactly what I ended comming up with not too long after posting the message. It seemed a bit round about and redundant, so i was not sure about it. Would it be correct to assume that since the tb.SelectAll works (selects the text in the original control) means that the tb is a pointer to the actual text box and not a copy of it? It would seem that you should be able to do it more directly, like
(TextBox)sender.SelectAll();or something similar.David Wilkes
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Thanks. That is alomost exactly what I ended comming up with not too long after posting the message. It seemed a bit round about and redundant, so i was not sure about it. Would it be correct to assume that since the tb.SelectAll works (selects the text in the original control) means that the tb is a pointer to the actual text box and not a copy of it? It would seem that you should be able to do it more directly, like
(TextBox)sender.SelectAll();or something similar.David Wilkes
amatbrewer wrote:
Would it be correct to assume that since the tb.SelectAll works (selects the text in the original control) means that the tb is a pointer to the actual text box and not a copy of it?
Yes.
amatbrewer wrote:
It would seem that you should be able to do it more directly, like (TextBox)sender.SelectAll(); or something similar.
Try this one:
((TextBox) sender).SelectAll();
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook
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Thanks. That is alomost exactly what I ended comming up with not too long after posting the message. It seemed a bit round about and redundant, so i was not sure about it. Would it be correct to assume that since the tb.SelectAll works (selects the text in the original control) means that the tb is a pointer to the actual text box and not a copy of it? It would seem that you should be able to do it more directly, like
(TextBox)sender.SelectAll();or something similar.David Wilkes
It would be safer not to assume that the sender is a TextBox (one day it won't be). Code like this:
TextBox tb = sender as TextBox;
if (tb != null)
{
tb.SelectAll();
}
else
{
// handle the error. Maybe just assert - it's a programming error
}Phil
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