How to position the popup based on the available space in Xamarin.Forms ComboBox?
To position the DropDown based on the available space in Xamarin.Forms Combobox.
- Create a CustomRenderer for the respective Android sample.
- Create a method for providing the position for PopUpWindow.
- Call the method in the DropDownOpen and TextChanged event to achieve the positioning.
Code snippet [C#]
public class CustomComboBoxRenderer : SfComboBoxRenderer
{
Syncfusion.Android.ComboBox.SfComboBox nativeComboBox;
public CustomComboBoxRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs<SfComboBox> e)
{
base.OnElementChanged(e);
nativeComboBox = Control;
Control.DropDownOpen += Control_DropDownOpen;
Control.TextChanged += Control_TextChanged;
}
private void Control_TextChanged(object sender, Syncfusion.Android.ComboBox.TextChangedEventArgs e)
{
if (!string.IsNullOrEmpty(nativeComboBox.Text))
{
setPopupPosition();
}
}
private void Control_DropDownOpen(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(nativeComboBox.Text))
{
setPopupPosition();
}
}
private void setPopupPosition()
{
int[] location = new int[2];
nativeComboBox.GetLocationOnScreen(location);
int x = location[0];
int y = location[1];
int ScreenWidth = Resources.DisplayMetrics.WidthPixels;
if (y <= ScreenWidth / 2)
{
y += nativeComboBox.Height;
nativeComboBox.GetAutoPopUpWindow().ShowAtLocation(nativeComboBox, GravityFlags.Top | GravityFlags.Start, x, y);
}
else
{
y = y - nativeComboBox.GetAutoPopUpWindow().Height;
nativeComboBox.GetAutoPopUpWindow().ShowAtLocation(nativeComboBox, GravityFlags.Top | GravityFlags.Start, x, y);
}
}
}
You can find the sample in the following link.
Conclusion
I hope you enjoyed learning about how to position the DropDown based on the available space in Xamarin.Forms ComboBox.
You can refer to our Xamarin.Forms ComboBox feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications.
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