Im currently working with xamarin form and Im beginner in this technology.
My problem is how to put some validation in my input fields. I watched videos on youtube about Xamarin community toolkit,its pretty good and cool, I can use some property later on, I cant find any solution on that video.
My expected output is; Let's say I have registration page, with 10 input fields, (e.g. Firstname(FN), Lastname(LN)). Assume I wont put any data in FN, and the rest 9 field is filled with datas so I cant click the "register" button cause the FN dont have any data.
Any link related to my post will be appreciated. Thank you sir.
You need to determine whether FN is null or empty. If it is null or empty, set the isenable to false.
You can try the code below
private void myEntry_TextChanged(object sender, TextChangedEventArgs e)
{
Entry fnentry = sender as Entry;
if (string.IsNullOrEmpty(fnentry.Text)){
Register.IsEnabled = false;
}
else
{
Register.IsEnabled = true;
}
}
<Entry x:Name="FirstName" TextChanged="myEntry_TextChanged"></Entry>
<Button x:Name="Register" Text="Register" IsEnabled="False"></Button>
Related
I have a ListView and am using the SelectedItem to call a command and show a modal view.
However, I have an issue where the user can tap multiple times on the listview row and multiple modal views are shown before the view has loaded. Granted this only happens on slower devices.
This is is caused because the command doesn't have any call back.
I wouldn't normally paste code here, but in this case I thought it was more descriptive to provide a screen shot.
I've looked into the AsyncCommands but these seem to be used more to handle errors.
I'm currently thinking about a subscribe approach which is triggered when the modal is exited, however I think there must be another way I haven't thought of.
Can you try using a Boolean as IsSelected & make IsSelected true when user clicks an item from list & change your condition in setter as below. When your operations are done reset the flag.
This was, there wont not be any duplication of modals. This is what I understood from your question, if there's something else, please let me know.
if( _locationAssetSelected || !IsSelected )
{
IsSelected = true;
_locationAssetSelected = value;
..... //your code
_locationAssetSelected = null;
IsSelected = false;
}
You could move the logic to the command to make sure it doesn't execute multiple times. This is a snippet on the sample/template Forms app which uses this method as a command. Lock seems unnecessary.
async void OnItemSelected(Item item)
{
//lock (selectLock)
//{
if (item == null || selectionOn)
return;
selectionOn = true;
//}
System.Diagnostics.Debug.WriteLine($"{item.Text} selected");
// This will push the ItemDetailPage onto the navigation stack
await Shell.Current.GoToAsync($"{nameof(ItemDetailPage)}?{nameof(ItemDetailViewModel.ItemId)}={item.Id}");
selectionOn = false;
}
I'd like to set readonly field, but only first line on the grid. How can I do this?
Any suggestions are welcome!
You can make use of the edit function like
edit: function(e) {
//add your custom logic here as if condition
//as for this example it just disable the one with id 1
//or maybe ada a new attribute like isEditable = boolean upon datasource.parse then check it
if (e.model.id == 1) {
//revert edited cell back to `read` mode
this.closeCell();
}
}
Well this is not exactly prevent opening, its just immediately close it after it opened i think. but it is viable option since i cant even see the changes. Working example dojo and this actually sugested in the kendo forum here
I'm using Laravel and I have a dropdown which fills its options from the database on load page and another text field.
Then on the submit I validate the text field to avoid empty entries, the validation is based on the request validator from Laravel. The validation is made correctly.
The problem is that when the validation is completed (it doesn't submit because i keep the text field empty) it returns to the page, but the dropdown remains selected with the last selection by the user, but in the back(sourcecode), its selected the original value that was loaded originally.
I want that the selectedIndex is the one original from the load page, not the last one selected. I tried with javascript but I had no luck change in it since it's already as the selectedIndex, but to the user, it still showing the other option. If I refresh manually it still showing the selected one incorrectly, I need to enter the URL manually so it shows correctly.
What could be a good approach to solve this "visual" issue?
Here is the controller code
public function update($user_id,GuardarBancoRequest $request)
{
$cuenta = user::whereId($user_id)->first();
$cuenta->nombrecompleto = Input::get('completo');
$temp = Input::get('tipo');
$cuenta->tipocuenta = Input::get('tipo');
$temp1 = Input::get('banco');
if ($temp == "1") {
$cuenta->cuentaclabe = Input::get('clabehidden');
$cuenta->cuentatarjeta = Input::get('cuentahidden');
} else {
$cuenta->cuentatarjeta = Input::get('cuentahidden');
$cuenta->cuentaclabe = Input::get('clabehidden');
}
if ( $temp1 == "10") {
$cuenta->otrobanco = Input::get('otro');
$cuenta->banco = "10";
} else {
$cuenta->banco = Input::get('banco');
$cuenta->save();
}
return Redirect::route('bancos.show',array(Auth::user()->id));
}
The dropdown that I'm referring is the [tipo] one
It's hard to presume without getting a chance to look at your code, but it sounds like when you do a redirect after validation you have something like
return redirect()->back()->withInput(); which causes fields to be prepopulated with the values entered earlier on the page. Remove withInput() portion in your controller if you have this.
Otherwise please mind posting your code in addition to your question, that would be helpful. (the controller part with the redirection and the view where you have the dropdown)
is there anyway to programmatically dismiss the drop-down list of an autocompletebox? my use case is as follows.
MainPage.xaml passes a value to SearchPage.xaml (i.e. /SearchPage.xaml?query=someText).
in SearchPage.xaml.cs, i set,
autoCompleteBox.Text = NavigationContext.QueryString["query"].
at this point, the drop-down list of suggested matches shows up. i don't want this behavior when the page is just navigated to.
i also tried the following to dismiss the drop-down list but it didn't help.
autoCompleteBox.Text = NavigationContext.QueryString["query"];
autoCompleteBox.IsDropDownOpen = false;
the drop-down list seems to go away from the AutoCompleteBox when it loses focuses, but i don't see a property/field to set to make it lose focus.
any help is appreciated.
well, i tinkered a bit and came up with a kludge. in the constructor of SearchPage.xaml.cs i have the following code.
autoCompleteBox.TextFilter += DummyFilter;
autoCompleteBox.GotFocus += (s,args) => {
if(!isAutoCompleteBoxInit) {
autoCompleteBox.TextFilter -= DummyFilter;
autoCompleteBox.TextFilter += RealFilter;
}
}
DummyFilter looks like the following.
bool DummyFilter(string search, string value) { return false; }
RealFilter looks like the following.
bool RealFilter(string search, string value) {
if(null != value) return value.ToLower().StartsWith(search.ToLower());
}
in my OnNavigatedTo method, is where i set, autoCompleteBox.Text = NavigationContext.QueryString["query"]. so when i do this now, the DummyFilter will always return false, so the drop-down list goes away. when the user focuses in on the AutoCompleteBox, i check if the correct Filter was already attached to the TextFilter property, if not, then i do a switch.
hope this helps some of you.
Is there any other focusable control on the page? Just set the focus somewhere else, and your problem should be solved.
When you have changed the text of the AutoCompleteBox the dropdown will open. Only when the user has changed the text and there is a match then the dropdown will close.
Just change userInitiated to true and when there is a match the dropdown will close.
private void UpdateTextCompletion(bool userInitiated)
{
userInitiated = true; ...
I have some validation code which should display the max / min of a control when a bad value is entered.
In my constructor I do this:
m_wndToolTip = gcnew ToolTip(this->components);
m_wndToolTip->AutoPopDelay = 5000;
m_wndToolTip->InitialDelay = 10;
m_wndToolTip->ReshowDelay = 250;
m_wndToolTip->ShowAlways = true;// Force the ToolTip text to be displayed whether or not the form is active.
This is my validation reflection code:
void MyGUI::IndicateValidationResult(Windows::Forms::Control^ control, bool isValid, String^ invalidReason)
{
// If the validation failed, make the background red. If not, turn it white.
if( isValid )
{
control->BackColor = Drawing::Color::White;
m_wndToolTip->Hide(control);
}
else
{
control->BackColor = Drawing::Color::LightCoral;
m_wndToolTip->Show(invalidReason, control);
}
}
...which is called from varous ValueChanged methods in my text boxes. I've tried using show and also a combination of SetToolTip and active = true and nothing seems to work.
I've seen another question asking about tooltips and have tried setting a nearby label in the call to show but that doesn't fix it either. The tooltip is a member variable in my System::Windows::Forms::Form derived form to stop it going out of scope.
Am I missing something obvious?
Your code worked fine when I tried it, there's no obvious mistake that I can see. I called it like this, using a Validating event of a text box:
bool ok;
System::Void textBox1_Validating(System::Object^ sender, System::ComponentModel::CancelEventArgs^ e) {
e->Cancel = !ok;
IndicateValidationResult(textBox1, ok, "invalid");
ok = !ok;
}
Beware that ToolTip can be cranky. The native Windows component has a "feature" that prevents a tooltip from showing again when it timed out before. The ErrorProvider component is a better mouse trap to get this done.