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将图像保存并检索到Windows Phone 8.1上的文件

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我是Windows手机编程的新手!我的问题是如何在Windows Phone 8.1中保存和检索图像到文件?我已经看到了一些链接,但所有这些链接都在windows phone 7中 . [http://www.geekchamp.com/tips/all-about-wp7-isolated-storage---read-and-save-images#][1]我不会这样,但这段代码只运行到windows phone 7

//在隔离存储中创建JPEG文件的文件名 . 字符串tempJPEG =“logo.jpg”;

// Create virtual store and file stream. Check for duplicate tempJPEG files.
        using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
        {
            if (myIsolatedStorage.FileExists(tempJPEG))
            {
                myIsolatedStorage.DeleteFile(tempJPEG);
            }

            IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile(tempJPEG);

            StreamResourceInfo sri = null;
            Uri uri = new Uri(tempJPEG, UriKind.Relative);
            sri = Application.GetResourceStream(uri);

            BitmapImage bitmap = new BitmapImage();
            bitmap.SetSource(sri.Stream);
            WriteableBitmap wb = new WriteableBitmap(bitmap);

            // Encode WriteableBitmap object to a JPEG stream.
            Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);

            //wb.SaveJpeg(fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
            fileStream.Close();
        }

1 回答

  • 0

    这是我将UI元素保存到png的方法:

    StorageFolder localFolder = ApplicationData.Current.TemporaryFolder;
                StorageFile file = await localFolder.CreateFileAsync(file.png, CreationCollisionOption.ReplaceExisting);
                var renderTargetBitmap = new RenderTargetBitmap();
                await renderTargetBitmap.RenderAsync(element);
                var pixels = await renderTargetBitmap.GetPixelsAsync();
    
                using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.ReadWrite))
                {
                    var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
                    byte[] bytes = pixels.ToArray();
                    encoder.SetPixelData(
                        BitmapPixelFormat.Bgra8,
                        BitmapAlphaMode.Straight,
                        (uint)renderTargetBitmap.PixelWidth,
                        (uint)renderTargetBitmap.PixelHeight,
                        DisplayInformation.GetForCurrentView().LogicalDpi,
                        DisplayInformation.GetForCurrentView().LogicalDpi,
                        bytes);
    
                    await encoder.FlushAsync();
                }
    

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