[英]convert byte[] to image
我已經將一個圖像作為byte[]
上傳到了我的數據庫中,現在我正試圖將其顯示出來。
發生錯誤-用戶代碼未處理參數異常Parameter is not valid
在這條線
newImage = System.Drawing.Image.FromStream(stream);
這是我的密碼
for (int i = 0; i < topRatingList.Count; i++)
{
int commentRating = topRatingList[i].CommentRating;
int drinkID = topRatingList[i].DrinkID;
if (i == 0)
{
DrinkMenuDAO drink = DrinkMenuBLL.getDrinkMenu(drinkID);
LinkButton1.Text = drink.DrinkName;
ImageButton1.ImageUrl = byteArrayToImage(drink.DrinkImage);
}
}
private string byteArrayToImage(byte[] byteArrayIn)
{
System.Drawing.Image newImage;
string strFileName = Server.MapPath("~/Temp/images/") + ".jpg";
if (byteArrayIn != null)
{
using (MemoryStream stream = new MemoryStream(byteArrayIn))
{
newImage = System.Drawing.Image.FromStream(stream);
newImage.Save(strFileName);
}
return strFileName;
}
else
{
return "";
}
}
我用來存儲圖像的代碼
protected void bn_upload_Click(object sender, EventArgs e)
{
lbl_msg.Text = "";
Stream imgStream = FileUpload1.PostedFile.InputStream;
BinaryReader imgBinary = new BinaryReader(imgStream);
bytes = imgBinary.ReadBytes((Int32)imgStream.Length);
imgBinary.Close();
imgStream.Close();
string src = byteArrayToImage(bytes);
if (src.Equals(""))
{
}
else
{
Image1.ImageUrl = "~/Temp/UploadedImage.jpg";
}
}
private string byteArrayToImage(byte[] byteArrayIn)
{
System.Drawing.Image newImage;
string strFileName = Server.MapPath("~/Temp/") + "UploadedImage.jpg";
if (byteArrayIn != null)
{
using (MemoryStream stream = new MemoryStream(byteArrayIn))
{
newImage = System.Drawing.Image.FromStream(stream);
newImage.Save(strFileName);
}
return strFileName;
}
else
{
return "";
}
}
protected void btn_submit_Click(object sender, EventArgs e)
{
DrinkMenuBLL.uploadImg(bytes);
lbl_msg.Text = "uploaded";
}
我在數據庫和我使用的SQL中使用了varbinary(MAX)
public static void UploadImg(byte[] drinkImage)
{
SqlConnection con = new SqlConnection(Constring.getConString());
string sql = "Update DrinkMenu set drinkImage = (@imgData) where drinkID = 4";
SqlCommand cmd = new SqlCommand(sql, con);
cmd.Parameters.Add("@imgData", SqlDbType.Binary).Value = drinkImage;
try
{
con.Open();
cmd.ExecuteNonQuery();
}
finally
{
con.Close();
cmd.Dispose();
con.Dispose();
}
}
一個問題可能是以下一個:
bytes = imgBinary.ReadBytes((Int32)imgStream.Length);
如果流的Length大於Int32.MaxValue,因為它是Int64,該怎么辦? 也許您正在截斷圖像...而是使用此方法將流讀取到緩沖區:
public static Byte[] ReadStream(Stream input)
{
Byte[] buffer = new Byte[(16 * 1024)];
using (MemoryStream stream = new MemoryStream())
{
Int32 read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
stream.Write(buffer, 0, read);
return stream.ToArray();
}
}
protected void bn_upload_Click(object sender, EventArgs e)
{
lbl_msg.Text = "";
Byte[] bytes = ReadStream(FileUpload1.PostedFile.InputStream);
String src = byteArrayToImage(bytes);
if (!src.Equals(""))
Image1.ImageUrl = "~/Temp/UploadedImage.jpg";
}
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