value property

T get value

Gets or sets the Dart value represented by this VARIANT.

When reading, the current vt field determines how the value is decoded. The decoded value must be assignable to T.

Supported return types include:

• null for VT_EMPTY and VT_NULL
• bool for VT_BOOL
• String for VT_BSTR
• IDispatch for VT_DISPATCH
• IUnknown for VT_UNKNOWN
• double for floating-point types (VT_R4, VT_R8)
• int for integer types (VT_I4, VT_I8, etc.)

When writing, the existing value is cleared before assigning the new one.

Supported input types include:

• null for VT_NULL
• bool for VT_BOOL
• String for VT_BSTR
• IDispatch for VT_DISPATCH
• IUnknown for VT_UNKNOWN
• double for 32-bit floating-point type (VT_R4)
• int for 32-bit signed integer type (VT_I4)

Implementation

T get value {
  final result = switch (vt) {
    VT_EMPTY || VT_NULL => null,
    VT_BOOL => boolVal,
    VT_BSTR => bstrVal.isNull ? null : bstrVal.toDartString(),
    VT_I1 => cVal,
    VT_I2 => iVal,
    VT_I4 => intVal,
    VT_I8 => llVal,
    VT_UI1 => bVal,
    VT_UI2 => uiVal,
    VT_UI4 => uintVal,
    VT_UI8 => ullVal,
    VT_R4 => fltVal,
    VT_R8 => dblVal,
    VT_DISPATCH => pdispVal,
    VT_UNKNOWN => punkVal,
    _ => this,
  };

  if (result is! T) {
    throw StateError(
      'Expected $T but got ${result?.runtimeType} for vt $vt.',
    );
  }

  return result;
}

set value (T value)

Implementation

set value(T value) {
  VariantClear(this);
  ZeroMemory(this, sizeOf<VARIANT>());

  if (value == null) {
    vt = VT_NULL;
    return;
  }

  switch (value) {
    case bool _:
      vt = VT_BOOL;
      boolVal = value;
    case double _:
      vt = VT_R4;
      dblVal = value;
    case IDispatch _:
      vt = VT_DISPATCH;
      pdispVal = value;
    case IUnknown _:
      vt = VT_UNKNOWN;
      punkVal = value;
    case int _:
      vt = VT_I4;
      intVal = value;
    case String _:
      vt = VT_BSTR;
      bstrVal = value.toBstr();
    default:
      throw ArgumentError.value(
        value,
        'value',
        'Unsupported VARIANT value type.',
      );
  }
}