Handle NumericUpDown percentage StringFormat correctly

[punker76]

Describe the changes you have made to improve this project

The current behavior for e.g. percentage text input with StringFotmat like P0 or {0:0.00%} converts the input one-to-one to the value:

100% = 100

This is not what the user expects, because the .Net default works different:

100% = 1

So this PR changes this behavior to the .Net default one.

Unit test

• ShouldConvertTextInputWithPercentageStringFormat
• ShouldConvertTextInputWithPermilleStringFormat
• ShouldFormatValueInput

Additional context

• If the stringformat is HEX the control has to accept [a..f] as Input as well.
• The DemoApp crashes on an invalid (Hex) Stringformat.

Closed Issues

Closes #3376

/cc @mgnslndh @timunie

[timunie]

@punker76 I'll have a look at this and let you know if I have any issues with the new implementation.

[timunie]

Hi @punker76

some more thoughts on your PR:

• Should we derivide from TextBox instead of control? That way some Properties would be implemented by default
• If the stringformat is HEX the control has to accept [a..f] as Input as well.
• Is a double- value precise enough? That way you cannot use decimal or ulong - values.
• The DemoApp crashes on an invalid Stringformat. Is there a way to handle this? Should we handle this?

Happy coding and a 💯 times thanks.
Tim

[timunie]

Good morning @punker76 ,

• Is a double- value precise enough? That way you cannot use decimal or ulong - values.

one addition: if we change the basetype to decimal we will also solve #2923 (it was closed in the past with a note that this would be a breaking change, we have a breaking change right now 😄 ) and #3673 .

Happy coding
Tim