/// <summary>
/// 将网络图片转化为Bitmap
/// </summary>
/// <param name="url"></param>
/// <returns></returns>
public static (Bitmap, string) UrlToBitmap(string url)
{
// 随机生成图片名称
var fileName = Guid.NewGuid().ToString("N");
Bitmap bitmap = null;
try
{
WebRequest request = WebRequest.Create(url);
using (Stream stream = request.GetResponse().GetResponseStream())
{
bitmap = new Bitmap(stream);
// 将png转化为jpg
if (bitmap.PixelFormat == PixelFormat.Format32bppArgb)
{
bitmap = bitmap.Clone(new Rectangle(0, 0, bitmap.Width, bitmap.Height), PixelFormat.Format24bppRgb);
fileName += ".png";
}
else
{
fileName += ".jpg";
}
return(bitmap, fileName);
}
}
catch (Exception ex)
{
LogHelperNLog.Error(ex);
fileName = "图片下载失败,检查[image_type]是否正确";
}
return(bitmap, fileName);
}
public static List <Bitmap> SrcToBitmap(IEnumerable <string> imageSrcs)
{
List <Bitmap> bitmaps = new List <Bitmap>();
foreach (var src in imageSrcs)
{
try
{
string[] srcLinux = src.Replace("\\", "/").Split('/');
List <string> Srcc = new List <string>();
Srcc.Add(AppDomain.CurrentDomain.BaseDirectory);
Srcc.AddRange(srcLinux);
var filePath = Path.Combine(Srcc.ToArray());
Bitmap bitmap = new Bitmap(filePath);
Bitmap bm = new Bitmap(bitmap.Width, bitmap.Height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(bm);
g.DrawImageUnscaled(bitmap, 0, 0);
g.Dispose();
bitmaps.Add(bm);
}
catch (Exception ex)
{
LogHelperNLog.Error(ex);
}
}
return(bitmaps);
}
/// <summary>
/// 文件转化为图片（多个文件）
/// </summary>
/// <param name="files"></param>
/// <returns>图片,base64,图片名</returns>
public static List <(Bitmap, string, string)> FileToBitmap(List <IFormFile> files)
{
List <(Bitmap, string, string)> bitmaps = new List <(Bitmap, string, string)>();
// 缓存路径
var filePath = string.Format(@"{0}{1}/", AppDomain.CurrentDomain.BaseDirectory, "Temp");
foreach (var file in files)
{
try
{
if (file.Length > 0)
{
// 后缀名
var fileExtension = Path.GetExtension(file.FileName).ToLower();
// 自动创建文件夹
if (!Directory.Exists(filePath))
{
Directory.CreateDirectory(filePath);
}
if (IMAGE_Extension.Contains(fileExtension))
{
using (var stream = file.OpenReadStream())
{
// 将文件转化为字节数组
byte[] arr = new byte[stream.Length];
stream.Read(arr, 0, (int)stream.Length);
//保存
//await file.CopyToAsync(stream);
Bitmap bitmap = new Bitmap(stream);
// 将png 转化为jpg,(PixelFormat.Format32bppRgb to PixelFormat.Format24bppRgb)
if (fileExtension == ".png")
{
bitmap = bitmap.Clone(new Rectangle(0, 0, bitmap.Width, bitmap.Height), PixelFormat.Format24bppRgb);
}
// 转化为BASE64
var fileName = Guid.NewGuid().ToString("N") + fileExtension;
//var img = Base64ToBitmap(Convert.ToBase64String(arr));
bitmaps.Add((bitmap, Convert.ToBase64String(arr), fileName));
}
}
}
}
catch (Exception ex)
{
LogHelperNLog.Error(ex, "FileCommon.FileToBitmapAsync 文件转换图片出错");
}
}
return(bitmaps);
}
/// <summary>
/// Base64转图片
/// </summary>
/// <param name="base64str"></param>
/// <returns>item1图片，item2图片名称</returns>
public static (Bitmap, string) Base64ToBitmap(string base64str)
{
Bitmap bitmap = null;
// 随机生成图片名称
var fileName = Guid.NewGuid().ToString("N");
// 去除头部
var reg = new Regex("data:image/(.*);base64,");
base64str = reg.Replace(base64str, "");
try
{
// 将base64转化为字节
var arr = Convert.FromBase64String(base64str);
using (MemoryStream ms = new MemoryStream(arr))
{
bitmap = new Bitmap(ms);
// 将png转化为jpg
if (bitmap.PixelFormat == PixelFormat.Format32bppArgb)
{
//bitmap = bitmap.Clone(new Rectangle(0, 0, bitmap.Width, bitmap.Height), PixelFormat.Format24bppRgb);
fileName += ".png";
}
else
{
fileName += ".jpg";
}
Bitmap bm = new Bitmap(bitmap.Width, bitmap.Height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(bm);
g.DrawImageUnscaled(bitmap, 0, 0);
g.Dispose();
bitmap = bm;
}
}
catch (Exception ex)
{
LogHelperNLog.Error(ex);
bitmap = null;
fileName = "Base64图片不正确";
}
return(bitmap, fileName);
}
