android - 打开文件管理并获取所选文件

Question

使用 Delphi XE 8 构建 Android 应用程序，我可以通过打开设备上安装的某个文件管理器应用程序浏览设备中的文件，然后取回所选文件名和路径吗？

Answer 1

unit ufmSelect;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.StdCtrls, FMX.Edit, FMX.Layouts, FMX.ListBox, FMX.Controls.Presentation;

type
  TCallback = procedure (ASelected: String) of object;

  TfmSelect = class(TForm)
    Panel1: TPanel;
    btnRefresh: TButton;
    lstItems: TListBox;
    edtCurrentFolder: TEdit;
    pnlDirectoryNotExist: TPanel;
    lblDirectoryNotExist: TLabel;
    btnSelect: TButton;
    procedure btnRefreshClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure lstItemsClick(Sender: TObject);
    procedure btnSelectClick(Sender: TObject);
  private
    { Private declarations }
  public
    const
      CONST_STRING_PARENT = '..';
      CONST_X = '/'; { I know is function for this }

    var
      Callback: TCallback;

    { Public declarations }
    function CD(AFolder: String): Boolean;
  end;

var
  fmSelect: TfmSelect;

implementation

{$R *.fmx}

uses
  System.IOUtils;

procedure TfmSelect.btnSelectClick(Sender: TObject);
var
  LResult: String;
begin
  if Assigned(Callback) then
    begin
      if lstItems.ItemIndex = -1 then
        LResult := EmptyStr
      else
        LResult := lstItems.Items[lstItems.ItemIndex];

      Callback(LResult);
    end;

  Close;
end;

function TfmSelect.CD(AFolder: String): Boolean;
var
  LParent: String;
  LDirs,
  LFiles: TStringDynArray;
  s: String;
begin
  lstItems.Clear;
  pnlDirectoryNotExist.Visible := False;
  if (AFolder <> EmptyStr) and (AFolder <> CONST_X) and (AFolder[AFolder.Length - 1] <> CONST_X) then
    AFolder := AFolder + CONST_X;
  edtCurrentFolder.Text := AFolder;

  { http://stackoverflow.com/questions/20318875/how-to-show-the-availble-files-in-android-memory-with-firemonkey }
  if not TDirectory.Exists(AFolder, True) then
    begin
      lblDirectoryNotExist.Text := 'Directory ' + AFolder + ' does not exist.';
      pnlDirectoryNotExist.Visible := True;
      Exit(False);
    end;

  { }
  LParent := TDirectory.GetParent(AFolder);

  { }
  if LParent <> AFolder then
    lstItems.Items.Add(CONST_STRING_PARENT);

  { }
  LDirs := TDirectory.GetDirectories(AFolder, '*');

  // Get all files. Non-Windows systems don't typically care about
  // extensions, so we just use a single '*' as a mask.
  LFiles := TDirectory.GetFiles(AFolder, '*');

  for s in LDirs do
    lstItems.Items.Add(s + CONST_X);

  for s in LFiles do
    lstItems.Items.Add(s);

  Result := True;
end;

procedure TfmSelect.FormCreate(Sender: TObject);
begin
  pnlDirectoryNotExist.Visible := False;
end;

procedure TfmSelect.lstItemsClick(Sender: TObject);
var
  s: String;
begin
  if lstItems.ItemIndex = -1 then
    Exit;

  if SameText(lstItems.Items[lstItems.ItemIndex], CONST_STRING_PARENT) then
    { Or we need to  use global var for Parent }
    CD(TDirectory.GetParent(edtCurrentFolder.Text))
  else
    begin
      s := lstItems.Items[lstItems.ItemIndex];

      if s = EmptyStr then
        Exit;

      if s[s.Length - 1] = CONST_X then
        CD(s);
    end;
end;

procedure TfmSelect.btnRefreshClick(Sender: TObject);
begin
  if edtCurrentFolder.Text <> EmptyStr then
    CD(edtCurrentFolder.Text)
  else
    CD(TPath.GetDocumentsPath);
end;

end.

使用示例

  if fmSelect = nil then
    begin
      Application.CreateForm(TfmSelect, fmSelect);
      fmSelect.Callback := Yahoo;
    end;
  fmSelect.Show;
  fmSelect.CD(TPath.GetDocumentsPath);


procedure TFormXX.Yahoo(ASelectedItem: String);
begin
  ShowMessage(ASelectedItem);
  //
end;