Dereference of a possibly null reference.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

Possible null reference argument for parameter 'format' in 'bool CustomMainForm.ParseQFormatString(string format, out int integral, out int fractional)'.

If possible, make the underlying type of ButtonFlags System.Int32 instead of ushort (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1028)

Rename type name ButtonFlags so that it does not end in 'Flags' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1711)

Type 'AngleConverter' is a static holder type but is neither static nor NotInheritable (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1052)

Do not declare visible instance fields (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1051)

Do not declare visible instance fields (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1051)