Net下二進(jìn)制形式的文件(圖片)的存儲與讀取
2008-05-11 12:19
.Net下圖片的常見存儲與讀取凡是有以下幾種:
存儲圖片:以二進(jìn)制的形式存儲圖片時(shí)，要把數(shù)據(jù)庫中的字段設(shè)置為Image數(shù)據(jù)類型(SQL Server),存儲的數(shù)據(jù)是Byte[].
1.參數(shù)是圖片路徑:返回Byte[]類型: public byte[] GetPictureData(string imagepath)
{
/**/////根據(jù)圖片文件的路徑使用文件流打開，并保存為byte[]
FileStream fs = new FileStream(imagepath, FileMode.Open);//可以是其他重載方法
byte[] byData = new byte[fs.Length];
fs.Read(byData, 0, byData.Length);
fs.Close();
return byData;
} 2.參數(shù)類型是Image對象，返回Byte[]類型: public byte[] PhotoImageInsert(System.Drawing.Image imgPhoto)
{
//將Image轉(zhuǎn)換成流數(shù)據(jù)，并保存為byte[]
MemoryStream mstream = new MemoryStream();
imgPhoto.Save(mstream, System.Drawing.Imaging.ImageFormat.Bmp);
byte[] byData = new Byte[mstream.Length];
mstream.Position = 0;
mstream.Read(byData, 0, byData.Length);
mstream.Close();
return byData;
} 好了,這樣通過上面的方法就可以把圖片轉(zhuǎn)換成Byte[]對象，然后就把這個對象保存到數(shù)據(jù)庫中去就實(shí)現(xiàn)了把圖片的二進(jìn)制格式保存到數(shù)據(jù)庫中去了。下面我就談?wù)勅绾伟褦?shù)據(jù)庫中的圖片讀取出來，實(shí)際上這是一個相反的過程。
讀取圖片:把相應(yīng)的字段轉(zhuǎn)換成Byte[]即：Byte[] bt=(Byte[])XXXX
1.參數(shù)是Byte[]類型，返回值是Image對象: public System.Drawing.Image ReturnPhoto(byte[] streamByte)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte);
System.Drawing.Image img = System.Drawing.Image.FromStream(ms);
return img;
} 2.參數(shù)是Byte[] 類型，沒有返回值，這是針對asp.net中把圖片從輸出到網(wǎng)頁上(Response.BinaryWrite)
public void WritePhoto(byte[] streamByte)
{
// Response.ContentType 的默認(rèn)值為默認(rèn)值為“text/html”
Response.ContentType = "image/GIF";
//圖片輸出的類型有: image/GIF image/JPEG
Response.BinaryWrite(streamByte);
} 補(bǔ)充:
針對Response.ContentType的值，除了針對圖片的類型外，還有其他的類型： Response.ContentType = "application/msword";
Response.ContentType = "application/x-shockwave-flash";
Response.ContentType = "application/vnd.ms-excel"; 另外可以針對不同的格式，用不同的輸出類型以適合不同的類型: switch (dataread("document_type"))
{
case "doc":
Response.ContentType = "application/msword";
case "swf":
Response.ContentType = "application/x-shockwave-flash";
case "xls":
Response.ContentType = "application/vnd.ms-excel";
case "gif":
Response.ContentType = "image/gif";
case "Jpg":
Response.ContentType = "image/jpeg";
} |
