2

为什么编译不出来？看起来很简单，但我不明白......是字符串数组的问题吗？错误是：

[dcc32 Error] Unit1.pas(94): E2250 There is no overloaded version of 'SelectDirectory' that can be called with these arguments.

这是代码：

{
function SelectDirectory(const StartDirectory: string; out Directories: TArray<string>; Options: TSelectDirFileDlgOpts = [];
  const Title: string = ''; const FolderNameLabel: string = ''; const OkButtonLabel: string = ''): Boolean; overload;
}

procedure TForm2.Browse1Click(Sender: TObject);
var
  iStartFolder: string;
  iDirectories: Array of string;
  iSelectedFolder: string;
begin
  iStartFolder := DesktopFolder;
  if SelectDirectory(iStartFolder, iDirectories,
    [sdHidePinnedPlaces, sdNoDereferenceLinks, sdForceShowHidden,
    sdAllowMultiselect], 'Select Folder', 'Folder', 'Ok') then
    ShowMessage(iDirectories[0]);
end;
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1 回答 1

7

第三个SelectDirectory()重载的第二个参数是out参数，所以你必须提供一个与参数类型相同的变量。您正在尝试在预期变量的位置传递array of string变量，因此出现错误。System.TArray<String>改用这个：

procedure TForm2.Browse1Click(Sender: TObject);
var
  iStartFolder: string;
  iDirectories: TArray<string>;
  iSelectedFolder: string;
begin
  iStartFolder := DesktopFolder;
  if SelectDirectory(iStartFolder, iDirectories,
    [sdHidePinnedPlaces, sdNoDereferenceLinks, sdForceShowHidden,
    sdAllowMultiselect], 'Select Folder', 'Folder', 'Ok') then
    ShowMessage(iDirectories[0]);
end;

虽然TArray<String>只是 的别名，但与参数array of string一起使用时，它们实际上是不同的类型。out

于 2015-09-01T00:57:33.943 回答