Xaml应用能不能从剪贴板获得图像或文本？（C++）

Question

如果可以，请写代码。

Answer 1

可以的，参考一下我同事写的一个博客 http://blogs.msdn.com/b/windows8devsupport/archive/2014/04/17/how-to-use-clipboard-class-in-windows-store-apps-.aspx

代码是C#的，不过C++是一样的写法。

--James

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Answer 2

我的代码是：

	Windows::ApplicationModel::DataTransfer::Clipboard^ a;
	auto b = a->GetContent();
	create_task(b->GetBitmapAsync()).then([this](Windows::Storage::Streams::RandomAccessStreamReference^ c){

	});

怎样将Windows::Storage::Streams::RandomAccessStreamReference^转换为图像？
图像是WriteableBitmap类型，也可以是Image控件的Source。

Answer 3

现在的问题是这样的：

代码：

	Windows::ApplicationModel::DataTransfer::Clipboard^ a;
	auto b = a->GetContent();
	create_task(b->GetBitmapAsync()).then([this](Windows::Storage::Streams::RandomAccessStreamReference^ c){
		create_task(c->OpenReadAsync()).then([this](Windows::Storage::Streams::IRandomAccessStreamWithContentType^ d){
			Windows::Storage::Streams::IBuffer^ e;
			create_task(d->ReadAsync(e, 0 - 1, Windows::Storage::Streams::InputStreamOptions::Partial))
				.then([this](Windows::Storage::Streams::IBuffer^){//标记1
				Windows::Storage::Streams::IRandomAccessStream^ h;
				h->WriteAsync(f);
				wb_->SetSource(h);
			});
		});
	});

在程序运行到标记1时，出现错误，自动停止。

跳转到App.g.hpp里，代码：

void ::实验::App::InitializeComponent()
{
#if defined _DEBUG && !defined DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
    UnhandledException += ref new Windows::UI::Xaml::UnhandledExceptionEventHandler(
        [](::Platform::Object^ sender, ::Windows::UI::Xaml::UnhandledExceptionEventArgs^ e)
        {
            (void)sender; // Unused parameter
            if (IsDebuggerPresent())
            {
                ::Platform::String^ errorMessage = e->Message;
                __debugbreak();//停止在这一行
            }
        });
#endif
}

怎么回事？

Answer 4

还有，保存图片似乎也不成功。

代码：（其中Pic是Image控件）

	auto PBU = Pic->BaseUri;
	auto PUBS = PBU->ToString();
	create_task(Windows::Storage::StorageFile::GetFileFromApplicationUriAsync(PBU))
		.then([this](Windows::Storage::StorageFile^ SF){
		Windows::ApplicationModel::DataTransfer::DataPackage^ DP = ref new Windows::ApplicationModel::DataTransfer::DataPackage();
		DP->SetBitmap(Windows::Storage::Streams::RandomAccessStreamReference::CreateFromFile(SF));
		Windows::ApplicationModel::DataTransfer::Clipboard^ CB;
		CB->SetContent(DP);
	});

但是Pic->BaseUri并不是图片的Uri。如果用别的方法，那么代码是：

	Windows::Storage::StorageFile^ SF;
	Windows::ApplicationModel::DataTransfer::DataPackage^ DP = ref new Windows::ApplicationModel::DataTransfer::DataPackage();

	//需要将Pic或wb_转为Windows::Storage::Streams::RandomAccessStreamReference^

	Windows::ApplicationModel::DataTransfer::Clipboard^ CB;
	CB->SetContent(DP);

我不知道怎么将图片转换为Windows::Storage::Streams::RandomAccessStreamReference^（wb_是WriteableBitmap^）

Answer 5

我已经成功了，你最近回复怎么这么慢啊？

代码：

	Windows::ApplicationModel::DataTransfer::Clipboard^ a;
	auto b = a->GetContent();
	if (!b->Contains(Windows::ApplicationModel::DataTransfer::StandardDataFormats::Bitmap)){
		return;
	}
	create_task(b->GetBitmapAsync()).then([this](Windows::Storage::Streams::RandomAccessStreamReference^ c){
		create_task(c->OpenReadAsync()).then([this](Windows::Storage::Streams::IRandomAccessStreamWithContentType^ d){
			auto m_bm = ref new WriteableBitmap(1, 1);
			m_bm->SetSource(d);
			int height = m_bm->PixelHeight, width = m_bm->PixelWidth;
			wb_ = ref new WriteableBitmap(m_bm->PixelWidth, m_bm->PixelHeight);
			unsigned int length;
			byte* temp_m_bm = GetPointerToPixelData(m_bm->PixelBuffer, &length);
			byte* temp_wb_ = GetPointerToPixelData(wb_->PixelBuffer, &length);
			for (unsigned int k = 0; k <unsigned int(height); k++){
				for (unsigned int i = 0; i < unsigned int(width * 4); i += 4){
					int pos = k * (width * 4) + (i);
					temp_wb_[pos + 0] = temp_m_bm[pos + 0];
					temp_wb_[pos + 1] = temp_m_bm[pos + 1];
					temp_wb_[pos + 2] = temp_m_bm[pos + 2];
					temp_wb_[pos + 3] = temp_m_bm[pos + 3];
				}
			}
			Pic->Source = wb_;
		});
	});

	auto saving = Windows::Storage::ApplicationData::Current->RoamingSettings;
	int elseing = 1;//保存
	if (saving->Values->HasKey("P4::ClipBoardSave")){
		Object^ saveValue = saving->Values->Lookup("P4::ClipBoardSave");
		if (saveValue != nullptr){
			elseing = 0;
			create_task(Windows::Storage::AccessCache::StorageApplicationPermissions::MostRecentlyUsedList->
				GetFileAsync(saveValue->ToString())).then([this](Windows::Storage::StorageFile^ file){
				if (file != nullptr){
					create_task(file->OpenAsync(FileAccessMode::ReadWrite)).then([this](IRandomAccessStream^ stream){
						create_task(BitmapEncoder::CreateAsync(BitmapEncoder::JpegEncoderId, stream)).then([this](BitmapEncoder^ encoder){
							Array<unsigned char>^ pixles = ref new Array < unsigned char >{};
							Windows::Security::Cryptography::CryptographicBuffer::CopyToByteArray(wb_->PixelBuffer, &pixles);
							encoder->SetPixelData(BitmapPixelFormat::Bgra8, BitmapAlphaMode::Ignore, wb_->PixelWidth, wb_->PixelHeight, 96.0, 96.0, pixles);
							encoder->FlushAsync();
							//保存完毕，开始写入剪贴板
							int elseing = 1;
							auto saving = Windows::Storage::ApplicationData::Current->RoamingSettings;
							if (saving->Values->HasKey("P4::ClipBoardOpen")){
								Object^ saveValue = saving->Values->Lookup("P4::ClipBoardOpen");
								if (saveValue != nullptr){
									elseing = 0;
									create_task(Windows::Storage::AccessCache::StorageApplicationPermissions::MostRecentlyUsedList->
										GetFileAsync(saveValue->ToString())).then([this](Windows::Storage::StorageFile^ file){
										auto DP = ref new Windows::ApplicationModel::DataTransfer::DataPackage();
										//	Windows::Storage::Streams::RandomAccessStreamReference^ RASR =
										//		ref new Windows::Storage::Streams::RandomAccessStreamReference();
										//	RASR->CreateFromFile(file);
										//	DP->SetBitmap(RASR);
										DP->SetBitmap(Windows::Storage::Streams::RandomAccessStreamReference::CreateFromFile(file));

										Windows::ApplicationModel::DataTransfer::Clipboard^ CB;
										CB->SetContent(DP);
									});
								}
							}
							if (elseing == 1){//需要得到mruToken
								auto openPicker = ref new Windows::Storage::Pickers::FileOpenPicker();
								openPicker->FileTypeFilter->Clear();
								openPicker->FileTypeFilter->Append("*");
								openPicker->FileTypeFilter->Append(".jpg");
								create_task(openPicker->PickSingleFileAsync()).then([this](Windows::Storage::StorageFile^ file){
									auto DP = ref new Windows::ApplicationModel::DataTransfer::DataPackage();
									//	Windows::Storage::Streams::RandomAccessStreamReference^ RASR =
									//		ref new Windows::Storage::Streams::RandomAccessStreamReference();
									//	RASR->CreateFromFile(file);
									//	DP->SetBitmap(RASR);
									DP->SetBitmap(Windows::Storage::Streams::RandomAccessStreamReference::CreateFromFile(file));

									Windows::ApplicationModel::DataTransfer::Clipboard^ CB;
									CB->SetContent(DP);
									auto saveValueString = Windows::Storage::AccessCache::StorageApplicationPermissions::MostRecentlyUsedList->Add(file);
									Windows::Storage::ApplicationData::Current->RoamingSettings->Values->Insert("P4::ClipBoardOpen", saveValueString);
								});
							}
							//粘贴完毕，将要自动返回
						});
					});
				}
				else{
					T9->Text = "文件已损坏，请自行修改";
				}
			});
		}
	}
	if (elseing == 1){//运行后直接返回，不进行粘贴
		auto Picker = ref new Windows::Storage::Pickers::FileSavePicker();
		auto plainTextExtensions = ref new Platform::Collections::Vector<String^>();
		plainTextExtensions->Append(".jpg");
		Picker->FileTypeChoices->Insert("JPG File", plainTextExtensions);
		create_task(Picker->PickSaveFileAsync()).then([this](Windows::Storage::StorageFile^ file){
			if (file != nullptr){
				auto saveValueString = Windows::Storage::AccessCache::StorageApplicationPermissions::MostRecentlyUsedList->Add(file);
				Windows::Storage::ApplicationData::Current->RoamingSettings->Values->Insert("P4::ClipBoardSave", saveValueString);
				create_task(file->OpenAsync(FileAccessMode::ReadWrite)).then([this](IRandomAccessStream^ stream){
					create_task(BitmapEncoder::CreateAsync(BitmapEncoder::JpegEncoderId, stream)).then([this](BitmapEncoder^ encoder){
						Array<unsigned char>^ pixles = ref new Array < unsigned char >{};
						Windows::Security::Cryptography::CryptographicBuffer::CopyToByteArray(wb_->PixelBuffer, &pixles);
						encoder->SetPixelData(BitmapPixelFormat::Bgra8, BitmapAlphaMode::Ignore, wb_->PixelWidth, wb_->PixelHeight, 96.0, 96.0, pixles);
						encoder->FlushAsync();
					});
				});
			}
		});
	}

Answer 6

多谢对论坛的支持，最近有点忙，不好意思，之后会继续给大家提供建议的，虽然我对C++不是很懂，不过这段时间我也在学习：）

--James

---

<THE CONTENT IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS OR IMPLIED>
Thanks
MSDN Community Support

Please remember to "Mark as Answer" the responses that resolved your issue. It is a common way to recognize those who have helped you, and makes it easier for other visitors to find the resolution later.

Answer 7

希望你可以尽快解决我提的关于视频截取图像的问题，我有点着急。

链接：

http://social.msdn.microsoft.com/Forums/zh-CN/508555b2-0c23-46fc-803a-801086e514e7/xaml2291420309251302146235270390572001330340222702068765311?forum=winstoreappzhcn

http://social.msdn.microsoft.com/Forums/zh-CN/8a5d5d31-1ff3-4d92-808c-300612854aa2/22914203092035129992transfervideoframe6531165288c65289?forum=winstoreappzhcn

Answer 8

对了，怎么样才能按照博客上的方法将图像（WriteableBitmap）写入剪贴板啊？（我原来的做法是通过保存文件然后写入，但是我希望更改这种方法）

C++和C#的解决方案都可以