Question

使用C ++ Builder 10.1 Berlin，我正在开发一款应用程序来扫描Android设备上的条形码。要获得条形码，我会通过Intent调用ZXing应用程序。当我扫描GSI-128条形码时，返回类型是CODE-128。在我的应用程序中，处理因条形码类型（128和GSI-128）而异。

是否有区分这些类型条形码的方法？

Answer 1

参见ZXing的文档：

Scanning Via Intent

ZXing提供IntentIntegrator类来启动扫描并解析结果。条形码类型位于ScanResults.formatName字段中。

如果您不想使用IntentIntegrator，则必须手动解析结果Intent。条形码类型在Intent的SCAN_RESULT_FORMAT额外字符串字段中可用。

无论哪种方式，您都可以使用FireMonkey的messaging framework来接收结果Intent。它将被包含在TMessageResultNotification消息中。

以下是Brian Long博客在Delphi中进行ZXing扫描的一个例子：

Launching activities and handling results in Delphi XE6 Android apps: Scanning a bar code

function LaunchActivityForResult(const Intent: JIntent; RequestCode: Integer): Boolean;
var
   ResolveInfo: JResolveInfo;
begin
   ResolveInfo := SharedActivity.getPackageManager.resolveActivity(Intent, 0);
   Result := ResolveInfo <> nil;
   if Result then
     SharedActivity.startActivityForResult(Intent, RequestCode);
end;

//For more info see https://github.com/zxing/zxing/wiki/Scanning-Via-Intent
procedure LaunchQRScanner(RequestCode: Integer);
var
   Intent: JIntent;
begin
   Intent := TJIntent.JavaClass.init(StringToJString('com.google.zxing.client.android.SCAN'));
   Intent.setPackage(StringToJString('com.google.zxing.client.android'));
   // If you want to target QR codes
   //Intent.putExtra(StringToJString('SCAN_MODE'), StringToJString('QR_CODE_MODE'));
   if not LaunchActivityForResult(Intent, RequestCode) then
     Toast('Cannot display QR scanner', ShortToast);
end;

uses
   System.Messaging,
   ...

type
   TMainForm = class(TForm)
     ...
   private
     const ScanRequestCode = 0;
     var FMessageSubscriptionID: Integer;
     procedure HandleActivityMessage(const Sender: TObject; const M: TMessage);
     function OnActivityResult(RequestCode, ResultCode: Integer; Data: JIntent): Boolean;
     ...
   end;
...
uses
   FMX.Platform.Android,
   Androidapi.Helpers,
   Androidapi.JNI.App,
   Androidapi.JNI.Toast,
   LaunchActivities,
   ...
procedure TMainForm.BarcodeScannerButtonClick(Sender: TObject);
begin
   FMessageSubscriptionID := TMessageManager.DefaultManager.SubscribeToMessage(TMessageResultNotification,
     HandleActivityMessage);
   LaunchQRScanner(ScanRequestCode);
end;

procedure TMainForm.HandleActivityMessage(const Sender: TObject; const M: TMessage);
begin
   if M is TMessageResultNotification then
     OnActivityResult(TMessageResultNotification(M).RequestCode, TMessageResultNotification(M).ResultCode,
       TMessageResultNotification(M).Value);
end;

function TMainForm.OnActivityResult(RequestCode, ResultCode: Integer; Data: JIntent): Boolean;
var
   ScanContent, ScanFormat: string;
begin
   Result :=  False;

   TMessageManager.DefaultManager.Unsubscribe(TMessageResultNotification, FMessageSubscriptionID);
   FMessageSubscriptionID := 0;

   // For more info see https://github.com/zxing/zxing/wiki/Scanning-Via-Intent
   if RequestCode = ScanRequestCode then
   begin
     if ResultCode = TJActivity.JavaClass.RESULT_OK then
     begin
       if Assigned(Data) then
       begin
         ScanContent := JStringToString(Data.getStringExtra(StringToJString('SCAN_RESULT')));
         ScanFormat := JStringToString(Data.getStringExtra(StringToJString('SCAN_RESULT_FORMAT')));
         Toast(Format('Found %s format barcode:'#10'%s', [ScanFormat, ScanContent]), LongToast);
       end;
     end
     else if ResultCode = TJActivity.JavaClass.RESULT_CANCELED then
     begin
       Toast('You cancelled the scan', ShortToast);
     end;
     Result :=  True;
   end;
end;

Answer 2

在使用startActivityForResult(intent,0);调用Intent之前，只需添加intent->putExtra(StringToJString("ASSUME_GS1"), true);的参数。如果条形码是GS1-128，前缀＆＃34;] C1＆＃34;将添加到您的条形码。

_di_JIntent intent;
msgID = TMessageManager::DefaultManager->SubscribeToMessage(__classid(TMessageResultNotification), &retourScanTel);
intent = TJIntent::Create();
intent->setAction(StringToJString("com.google.zxing.client.android.SCAN"));
intent->putExtra(StringToJString("ASSUME_GS1"), true);
SharedActivity()->startActivityForResult(intent,0);

Zxing：区分128条码和GSI-128

2 个答案: