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.net二进制形式存储文件与图片的实例代码
来源: 互联网 发布时间:2014-08-30
本文导语: 在.Net下图片的常见存储与读取,可以分为如下几种: 存储图片: 以二进制的形式存储图片时,要把数据库中的字段设置为Image数据类型(SQL Server),存储的数据是Byte[]。 1,参数是图片路径:返回Byte[]类型: 代码示例: public by...
在.Net下图片的常见存储与读取,可以分为如下几种:
存储图片:
以二进制的形式存储图片时,要把数据库中的字段设置为Image数据类型(SQL Server),存储的数据是Byte[]。
1,参数是图片路径:返回Byte[]类型:
代码示例:
public byte[] GetPictureData(string imagepath)
{
////根据图片文件的路径使用文件流打开,并保存为byte[]
FileStream fs = new FileStream(imagepath, FileMode.Open);//可以是其他重载方法
byte[] byData = new byte[fs.Length];
fs.Read(byData, 0, byData.Length);
fs.Close();
return byData;
}
{
////根据图片文件的路径使用文件流打开,并保存为byte[]
FileStream fs = new FileStream(imagepath, FileMode.Open);//可以是其他重载方法
byte[] byData = new byte[fs.Length];
fs.Read(byData, 0, byData.Length);
fs.Close();
return byData;
}
2,参数类型是Image对象,返回Byte[]类型:
代码示例:
public byte[] PhotoImageInsert(System.Drawing.Image imgPhoto)
{
//将Image转换成流数据,并保存为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;
}
{
//将Image转换成流数据,并保存为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;
}
以上方法可以把图片转换成Byte[]对象,然后就把这个对象保存到数据库中,即可实现把图片的二进制格式保存到数据库中。
下面学习如何把数据库中的图片读取出来。
读取图片:把相应的字段转换成Byte[]即:Byte[] bt=(Byte[])XXXX
1,参数是Byte[]类型,返回值是Image对象:
代码示例:
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;
}
{
System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte);
System.Drawing.Image img = System.Drawing.Image.FromStream(ms);
return img;
}
2,参数是Byte[] 类型,没有返回值,这是针对asp.net中把图片从输出到网页上(Response.BinaryWrite)
代码示例:
public void WritePhoto(byte[] streamByte)
{
// Response.ContentType 的默认值为默认值为“text/html”
Response.ContentType = "image/GIF";
//图片输出的类型有: image/GIF image/JPEG
Response.BinaryWrite(streamByte);
}
{
// Response.ContentType 的默认值为默认值为“text/html”
Response.ContentType = "image/GIF";
//图片输出的类型有: image/GIF image/JPEG
Response.BinaryWrite(streamByte);
}
补充:
针对Response.ContentType的值,除了针对图片的类型外,还有其他的类型:
代码示例:
Response.ContentType = "application/msword";
Response.ContentType = "application/x-shockwave-flash";
Response.ContentType = "application/vnd.ms-excel";
Response.ContentType = "application/x-shockwave-flash";
Response.ContentType = "application/vnd.ms-excel";
另外,可以针对不同的格式,用不同的输出类型以适合不同的类型:
代码示例:
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";
}
{
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";
}
参考:
代码示例:
Image image= GetImageFromClipboard();//从剪切板获取图像
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.Runtime.Serialization.Formatters.Binary.BinaryFormatter formatter
= new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter(); formatter.Serialize(stream, image);
FileStream fs=new FileStream("xx",FileMode.Open,FileAccess.Write);
fs.Write(stream.ToArray(),0,stream.ToArray().Length);
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.Runtime.Serialization.Formatters.Binary.BinaryFormatter formatter
= new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter(); formatter.Serialize(stream, image);
FileStream fs=new FileStream("xx",FileMode.Open,FileAccess.Write);
fs.Write(stream.ToArray(),0,stream.ToArray().Length);