delphi 蓝牙连接打印机演示

unit Main;

interface

uses

Bluetooth.Printer,

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,

System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,

Vcl.StdCtrls;

type

TfrmMain = class(TForm)

btnImprimir: TButton;

cbxDevice: TComboBox;

Memo1: TMemo;

procedure FormCreate(Sender: TObject);

procedure FormDestroy(Sender: TObject);

procedure btnImprimirClick(Sender: TObject);

private

FPrinter: TBluetoothPrinter;

procedure PopularComboBoxDevices;

public

end;

var

frmMain: TfrmMain;

implementation

uses

System.Bluetooth;

{$R *.dfm}

procedure TfrmMain.PopularComboBoxDevices;

var

Device: TBluetoothDevice;

begin

cbxDevice.Items.BeginUpdate;

try

cbxDevice.Clear;

for Device in FPrinter.PairedDevices do

cbxDevice.Items.Add(Device.DeviceName);

finally

cbxDevice.Items.EndUpdate;

end;

procedure TfrmMain.FormCreate(Sender: TObject);

begin

FPrinter := TBluetoothPrinter.Create(Self);

FPrinter.Enabled := True;

PopularComboBoxDevices;

end;

procedure TfrmMain.FormDestroy(Sender: TObject);

begin

FPrinter.Free;

end;

procedure TfrmMain.btnImprimirClick(Sender: TObject);

begin

if cbxDevice.Text = '' then

raise Exception.Create('Escolha primeiramente uma impressora da lista!');

if Memo1.Lines.Text.Trim.IsEmpty then

raise Exception.Create('Nenhum texto foi digitado, impossível continuar!');

FPrinter.PrinterName := cbxDevice.Text;

FPrinter.Imprimir(Memo1.Lines.Text);

end;

end.

单元文件：Bluetooth.Printer.pas

unit Bluetooth.Printer;

interface

uses

System.SysUtils, System.Bluetooth, System.Bluetooth.Components;

type

EBluetoothPrinter = class(Exception);

TBluetoothPrinter = class(TBluetooth)

private

FSocket: TBluetoothSocket;

FPrinterName: String;

function ConectarImpressora(ANomeDevice: String): Boolean;

function GetDeviceByName(ANomeDevice: String): TBluetoothDevice;

public

procedure Imprimir(const ATexto: String);

published

property PrinterName: String read FPrinterName write FPrinterName;

end;

const

UUID = '{00001101-0000-1000-8000-00805F9B34FB}';

implementation

function TBluetoothPrinter.GetDeviceByName(ANomeDevice: String): TBluetoothDevice;

var

lDevice: TBluetoothDevice;

begin

Result := nil;

for lDevice in Self.PairedDevices do

begin

if lDevice.DeviceName = ANomeDevice then

Result := lDevice;

end;

function TBluetoothPrinter.ConectarImpressora(ANomeDevice: String): Boolean;

var

lDevice: TBluetoothDevice;

begin

lDevice := GetDeviceByName(ANomeDevice);

if lDevice <> nil then

begin

FSocket := lDevice.CreateClientSocket(StringToGUID(UUID), False);

if FSocket <> nil then

begin

FSocket.Connect;

Result := FSocket.Connected

end

else

raise EBluetoothPrinter.Create('Ocorreu um erro ao obter socket de conexão bluetooth.');

end

else

raise EBluetoothPrinter.CreateFmt('Impressora "%s" não encontrada ou não pareada.', [ANomeDevice]);

end;

procedure TBluetoothPrinter.Imprimir(const ATexto: String);

begin

if ConectarImpressora(Self.PrinterName) then

begin

try

FSocket.SendData(TEncoding.UTF8.GetBytes(ATexto));

finally

FSocket.Close;

end;

end

else

raise EBluetoothPrinter.Create('Não foi possível conectar a impressora.');

end;

end.

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