wpf Image and Drawing.Image

最新推荐文章于 2024-09-27 16:32:01 发布

js_ho

最新推荐文章于 2024-09-27 16:32:01 发布

阅读量2.7k

点赞数

CC 4.0 BY-SA版权

分类专栏： Wpf 文章标签： image wpf extension stream string byte

本文链接：https://blog.youkuaiyun.com/js_ho/article/details/6234274

Wpf 专栏收录该内容

4 篇文章

订阅专栏

本文介绍了一种在WPF应用程序中处理图片的方法，包括从网络下载图片并将其转换为不同格式，以及调整图片大小等实用功能。文章还提供了一个实用的C#类，用于实现这些功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

wpf 中的imge和drawing 中的iamge相互转换

public class ImageHelper {
private static List<string> allowableFileTypes = new List<string>();

        static ImageHelper() {
            allowableFileTypes.Clear();
            allowableFileTypes.Add(".jpg");
            allowableFileTypes.Add(".jpeg");
            allowableFileTypes.Add(".bmp");
            allowableFileTypes.Add(".png");
            allowableFileTypes.Add(".tif");
            allowableFileTypes.Add(".tiff");
            allowableFileTypes.Add(".gif");
            allowableFileTypes.Add(".wmp");
        }

#region << _helper method >>

        public static bool SaveImageOnDisk(String originalUrl, String filename, out String errorMessage) {
            try {
                WebClient client = new WebClient();
                byte[] buffer = client.DownloadData(originalUrl);

client.Dispose();

                //文件后缀名
                string extension = filename.LastIndexOf(".") > -1 ?
                    filename.Substring(filename.LastIndexOf(".")) : ".jpg";

                //是否在默认值中存在
                if (!allowableFileTypes.Contains(extension)) {
                    errorMessage = "The file type you picked is not supported/r/n" +
                                    "Or you didn't enter a file extension, please retry";
                    return false;
                }

BitmapSource imageSource = CreatImage(buffer, 0, 0);
byte[] encodedBytes = GetEncodedImageData(iamgeSource, extension);

SaveImageData(encodedBytes, filename);
errorMessage = String.Empty;

                return true;
            }
            catch (Exception ex) {
                errorMessage = ex.Message;
                return false;
            }
        }

        /// <summary>
        /// 将图片保存到本地
        /// </summary>
        /// <param name="data"></param>
        /// <param name="fileName"></param>
        public static void SaveImageData(byte[] data, string fileName) {
            FileStream stream = new FileStream(fileName, FileMode.Create, FileAccess.Write);
            BinaryWriter bw = new BinaryWriter(stream);
            bw.Write(data);
            bw.Close();
            stream.Close();
        }

public static BitmapSource CreatImage(byte[] data, int decodePixelWidth, int decodePixelHeight) {
if (data == null) return null;

BitmapImage result = new BitmapImage();

result.BeginInit();

            if (decodePixelWidth > 0) {
                result.DecodePixelWidth = decodePixelWidth;
            }

            if (decodePixelHeight > 0) {
                result.DecodePixelHeight = decodePixelHeight;
            }

            result.StreamSource = new MemoryStream(data);
            result.CreateOptions = BitmapCreateOptions.None;
            result.CacheOption = BitmapCacheOption.Default;

result.EndInit();

return result;
}

public static byte[] GetEncodedImageData(ImageSource image, String preferredFormat) {

byte[] result = null;

//图片解码器
BitmapEncoder encoder = null;

            switch (preferredFormat.ToLower()) {
                case ".jpg":
                case ".jpeg":
                    encoder = new JpegBitmapEncoder();
                    break;

                case ".bmp":
                    encoder = new BmpBitmapEncoder();
                    break;

                case ".png":
                    encoder = new PngBitmapEncoder();
                    break;

                case ".tif":
                case ".tiff":
                    encoder = new TiffBitmapEncoder();
                    break;

                case ".gif":
                    encoder = new GifBitmapEncoder();
                    break;

                case ".wmp":
                    encoder = new WmpBitmapEncoder();
                    break;
            }

            if (image is BitmapSource) {
                MemoryStream stream = new MemoryStream();
                encoder.Frames.Add(BitmapFrame.Create(image as BitmapSource));

encoder.Save(stream);
stream.Seek(0, SeekOrigin.Begin);

result = new byte[stream.Length];

BinaryReader br = new BinaryReader(stream);

                br.Read(result, 0, (int)stream.Length);
                br.Close();
                stream.Close();
            }

return result;
}

#endregion