Wrap type conversions in try-catch to prevent crashes due to unhandled exceptions

[BAndysc]

What does the pull request do?

This PR prevents crashes due to illegal conversions in TargetTypeConverter, i.e. if a numeric type is bound to a TextBox (only when using CompiledBindings). Yes, currently in 11.1 if you type a letter in a textbox with {Binding NumericType}, it will crash the whole app (with CompiledBindings).

What is the current behavior?

The type conversion exceptions in Compiled Bindings are not handled.

What is the updated/expected behavior with this PR?

The type conversion exceptions are silently ignored - just like before the binding refactor.

How was the solution implemented (if it's not obvious)?

The conversion happens in TryConvert methods, which name implies that a failure should not propagate. It also worked this way before:

Avalonia/src/Avalonia.Base/Utilities/TypeUtilities.cs

Lines 279 to 290 in d407764

	try
	{
	result = Convert.ChangeType(value, to, CultureInfo.InvariantCulture);
	return true;
	}
	catch
	{
	result = null;
	return false;
	}
	}
	}

So I added analogous try {} catch {} in the new typed conveter.

Checklist

• Added unit tests
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

n/a

Obsoletions / Deprecations

Fixed issues

Fixes #15546

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0048162-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[cla-avalonia]

• All contributors have signed the CLA.

[BAndysc]

@cla-avalonia agree

[workgroupengineering]

In my opinion, the error should be added to the Binding log instead of ignoring it completely.

[BAndysc]

Typing a letter in a number field is an user error and it would spam the log.

[workgroupengineering]

Without exceptions or messages in log it would be difficult to identify any errors in a Converter. The log level can be customized.

[BAndysc]

Without exceptions or messages in log it would be difficult to identify any errors in a Converter. The log level can be customized.

The exception will be shown in Data Validation of the control. This PR refers only to built in Type Converters, i.e. if you bind an integer into a TextBox's Text

[grokys]

LGTM, thanks! Quite an oversight there! (I really wish TypeConverter had TryX methods!)