C# 转换函数 （Stream to Byte[],Byte to Image,Image to Byte[],Image缩放,Byte[] to Bitmap）

1.Stream转byte[]
 
public
byte[]
StreamToByteArr(Stream
stream)
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byte[]
bytes
=
new
byte[stream.Length];
//创建byte数组

   
stream.Read(bytes,
0,
bytes.Length);
//将Stream读入byte数组

  
stream.Seek(0,
SeekOrigin.Begin);//
将流指向起始位置
   
return
bytes;

 }

2. byte[]转Image
public
static
Image
GetImageByBytes(byte[]
bytes)
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Image
photo
=
null;
 
using
(MemoryStream
ms
=
new
MemoryStream(bytes))
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ms.Write(bytes,
0,
bytes.Length);
    
photo
=
Image.FromStream(ms,
true);
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return
photo;

}

3.Image转Byte[]
public
byte[]
GetByteImage(Image
img)
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byte[]
bt
=
null;
 
if
(!img.Equals(null))
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using
(MemoryStream
mostream
=
new
MemoryStream())
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Bitmap
bmp
=
new
Bitmap(img);
     
bmp.Save(mostream,
System.Drawing.Imaging.ImageFormat.Bmp);
     
bt
=
new
byte[mostream.Length];
     
mostream.Position
= 0;
     
mostream.Read(bt,
0,
Convert.ToInt32(bt.Length));
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return
bt;

}

4.Image图片缩放
public
Image
pictureProcess(Image
sourceImage,
int
targetWidth,
int
targetHeight)
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int
width;//图片最终的宽 
 
int
height;//图片最终的高 
 
try
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System.Drawing.Imaging.ImageFormat
format
=
sourceImage.RawFormat;
   
Bitmap
targetPicture
=
new
Bitmap(targetWidth,
targetHeight);
   
Graphics
graphics
=
Graphics.FromImage(targetPicture);
   
graphics
.Clear(Color.White);
   
//计算缩放图片的大小 
   
if
(sourceImage.Width
>
targetWidth
&&
sourceImage.Height
<=
targetHeight)
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width
=
targetWidth;
     
height
= (width
*
sourceImage.Height)
/
sourceImage.Width;
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else
if
(sourceImage.Width
<=
targetWidth
&&
sourceImage.Height
>
targetHeight)
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height
=
targetHeight;
    
 
width
= (height
*
sourceImage.Width)
/
sourceImage.Height;
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else
if
(sourceImage.Width
<=
targetWidth
&&
sourceImage.Height
<=
targetHeight)
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width
=
sourceImage.Width;
     
height
=
sourceImage.Height;
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else
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width
=
targetWidth;
     
height
= (width
*
sourceImage.Height)
/
sourceImage.Width;
     
if
(height
>
targetHeight)
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height
=
targetHeight;
       
width
= (height
*
sourceImage.Width)
/
sourceImage.Height;
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graphics
.DrawImage(sourceImage,
(targetWidth
-
width) / 2, (targetHeight
-
height) / 2,
width,
height);
    
sourceImage.Dispose();
    
return
targetPicture;
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catch
(Exception
ex)
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return
null;

}

5.byte[] 转bitmap
 public
static
Bitmap
BytesToBitmap(byte[]
Bytes)
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MemoryStream
stream
=
null;
  
try
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stream
=
new
MemoryStream(Bytes);
     
return
new
Bitmap((Image)new
Bitmap(stream));
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catch
(ArgumentNullException
ex)
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throw
ex;
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catch
(ArgumentException
ex)
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throw
ex;
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finally
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stream.Close();
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}