Advice on checking if inputs are empty (.NET)
In my form, I have 8 textboxes. All of these need to be filled in, and I wanted to ch开发者_如何学JAVAeck if they are filled in before going to run the rest of the code.
The only way I've done it thus far is 8 nested IF statements, and this looks unorganised and seems like a horrible way to do it.
Can someone tell me a better way to do this? If there is one, of course.
Thanks :)
Is this winforms or webforms?
If Winforms, look at the ErrorProvider control.
If Webforms, look at the validation controls (specifcally, RequiredFieldValidator).
In either case, I would likely create a custom control that wraps the validation together with the textbox that you can just drop on your form where you need it.
Hmm, how about grouping the 8 textboxes into 1 Panel and looping through each of them instead? Something like this:
bool text = true;
foreach(Control ctrl in Panel)
{
TextBox textbox = ctrl as TextBox;
if (box.Text.Length == 0)
{
DisplayErrorMsg();
text = false;
}
}
if(text) ExecuteCode();
At form load time, make a collection of all the textboxes that cannot be empty. Then simply loop through them. This is similar to @Kronon answer, but without the Panel. I like changing the background color to indicate which fields should not be empty.
public partial class MainForm
{
private List<TextBox> mandatoryTextBoxes;
private void MainForm_Load(object sender, EventArgs e) {
mandatoryTextBoxes = new List<TextBox>();
mandatoryTextBoxes.Add(this.textBox1);
// add other textboxes1
}
private bool CheckMandatoryFields() {
bool allFieldsPresent = true;
foreach (TextBox tb in this.mandatoryTextBoxes) {
if (tb.Text.Length == 0) {
tb.BackColor = Color.Yellow;
allFieldsPresent = false;
} else {
tb.BackColor = Color.White;
}
}
return allFieldsPresent;
}
private void DoWork() {
if (!this.CheckMandatoryFields()) {
this.SetError("Indicated fields cannot be empty");
return;
}
// do real work here
}
}
Simply use RequiredFieldValidator along with the ValidatorSummary field to display the validation messages.
Let me know if that helps.
Pratik
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