Country Flag Display

This feature allows developers to control whether a country flag image is displayed alongside the phone number input based on the current country settings.

Overview

The Country Flag Display feature is controlled primarily through the following public property:

Property	Type	Default	Description
ShowCountryFlag	bool	true	Determines if the country flag image is rendered inside the control, typically based on the current ISO code.

When the property is enabled and a valid ISO country code is set (via ISOCountryCode or indirectly via CountryCode/SelectedCountry), the control loads an image resource representing the country's flag. The flag is then displayed on the control’s right side and the control automatically adjusts its text padding to accommodate the flag.

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Key Points

Aspect	Detail
Image Loading	The control dynamically loads the flag image resource based on the current ISO country code.
Padding Adjustment	When the flag is visible, the text padding is automatically updated to ensure proper layout.
Dynamic Updates	Changes to ISOCountryCode or CountryCode trigger a reload of the flag image and refresh the display accordingly.

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Best Practices

Practice	Explanation
Maintain Consistent Country Codes	Always update ISOCountryCode or use CountryCode in conjunction with SelectedCountry to ensure the correct flag is loaded.
Validate Resource Availability	Ensure that flag image resources exist in the expected resource path for all supported ISO codes.
Use Flag Display for Clarity	Enable ShowCountryFlag when you want to provide a visual cue of the country context for the phone number input.

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Common Pitfalls

Pitfall	How to Avoid
Missing Flag Resource	If a resource image for a given ISO code is not found, the flag will not display. Ensure that all necessary flag images are included.
Incorrect ISO Code Updates	When updating CountryCode or SelectedCountry, verify that ISOCountryCode is updated appropriately so that the flag image corresponds correctly.
Overriding Padding Manually	Do not manually override TextPadding if relying on automatic adjustment for flag display; use UpdateTextPadding methods provided by the control.

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Usage Scenarios

Scenario	Example Use Case
International Dialing Interface	Display the country flag to indicate the current dialing code as users switch between different countries.
Localized User Interfaces	Use the flag display to enhance visual clarity when the application is designed for a global audience, showing a recognizable flag.
Dynamic Flag Updates Based on User Input	Automatically update the flag image when the user types or pastes a different country code, thereby providing real-time feedback.

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Code Examples

Example 1: Basic Flag Display Setup This sample demonstrates enabling the country flag display with default settings. The control automatically loads the flag image for the configured country.

// Create a new instance of the phone number box control
SiticonePhoneNumberBox phoneNumberBox = new SiticonePhoneNumberBox();

// Enable the country flag display (this is the default behavior)
phoneNumberBox.ShowCountryFlag = true;

// Configure country settings to ensure the correct flag is loaded
phoneNumberBox.SelectedCountry = Country.UnitedStates;
phoneNumberBox.ISOCountryCode = "us";
phoneNumberBox.CountryCode = "1";

// Set location and size for integration in the form
phoneNumberBox.Location = new Point(20, 20);
phoneNumberBox.Size = new Size(250, 40);

// Add the control to the form
this.Controls.Add(phoneNumberBox);

Example 2: Dynamically Toggling Flag Visibility This sample demonstrates how to toggle the flag display at runtime based on user actions.

// Assume phoneNumberBox is already added to the form
private void ToggleFlagButton_Click(object sender, EventArgs e)
{
    // Toggle the visibility of the country flag
    phoneNumberBox.ShowCountryFlag = !phoneNumberBox.ShowCountryFlag;
    
    // Optionally, update text padding if necessary
    // The control internally calls UpdateTextPadding when ShowCountryFlag changes
    phoneNumberBox.Invalidate(); // Force a redraw of the control
}

Example 3: Changing Country and Automatically Updating Flag This sample shows how to change the country settings, which automatically reloads the flag image.

// Assume phoneNumberBox is already instantiated on the form
private void OnCountrySelectionChanged(object sender, EventArgs e)
{
    // Assume a ComboBox is used to select a country
    Country selected = (Country)comboBoxCountry.SelectedItem;
    
    // Update the country setting
    phoneNumberBox.SelectedCountry = selected;
    
    // The control automatically updates ISOCountryCode and reloads the flag image
    // It also updates text padding to accommodate the flag if ShowCountryFlag is true
}

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Review

Aspect	Review Comment
Resource Management	The control manages the flag image resources dynamically and disposes of them appropriately upon updates.
Automatic Layout	Text padding is recalculated when the flag display state changes, ensuring a consistent user interface.
Dynamic User Feedback	Real-time updates when the country changes enhance the user experience by reflecting the current dialing context.

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Summary

The Country Flag Display feature of the SiticonePhoneNumberBox control provides a visual indication of the country associated with the phone number input. By controlling the ShowCountryFlag property and ensuring that country codes are correctly set, developers can offer a more localized and intuitive experience. The feature automatically handles resource loading and layout adjustments, reducing the need for manual configuration.

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Additional Notes

Note Type	Detail
Extensibility	The control’s design allows further extension or customization by overriding resource paths if custom flag images are needed.
Integration Simplicity	With automatic updates based on country properties, the flag display feature integrates seamlessly into most WinForms applications.
UI Consistency	Ensure that any customization to padding or country code settings is coordinated with the flag display to maintain visual consistency.