android中bitmap图片与二进制，String间的转化

1，

public Bitmap stringtoBitmap(String string) {                 // 将字符串转换成Bitmap类型                 Bitmap bitmap = null;                 try {                         byte[] bitmapArray;                         bitmapArray = Base64.decode(string, Base64.DEFAULT);                         bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0,                                         bitmapArray.length);                 } catch (Exception e) {                         e.printStackTrace();                 }

return bitmap;         }

public String bitmaptoString(Bitmap bitmap) {

// 将Bitmap转换成字符串                 String string = null;                 ByteArrayOutputStream bStream = new ByteArrayOutputStream();                 bitmap.compress(CompressFormat.PNG, 100, bStream);                 byte[] bytes = bStream.toByteArray();                 string = Base64.encodeToString(bytes, Base64.DEFAULT);                 return string;         }

2，

Byte()转换成Bitmap

Dim ms As MemoryStream =  New MemoryStream(bytes)

ms.Position = 0

Dim img As Image =  Image.FromStream(ms)

ms.Close()

Bitmap转化为Byte()

Public Function BitmapToByte() As Byte()

Dim BitReturn As Bitmap =  New Bitmap()

Dim bReturn() As Byte =  Nothing

Dim ms As MemoryStream =  New MemoryStream()

BitReturn.Save(ms, System.Drawing.Imaging.ImageFormat.Png)

bReturn = ms.GetBuffer()

End Function

Byte()与String的转换代码

Dim converter As System.Text.UnicodeEncoding

converter = New System.Text.UnicodeEncoding()
Dim inputBytes() As Byte = converter.GetBytes(inputString)

Dim inputString As String = converter.GetString(inputBytes)

Dim inputString As String = System.Convert.ToBase64String(inputBytes)

Dim inputBytes() As Byte =  System.Convert.FromBase64String(inputString)

Stream和Byte()之间的转换

Public Function StreamToBytes(byval stream as Stream) As Byte

Dim bytes() As Byte =  New Byte(stream.Length) {}

stream.Read(bytes, 0, bytes.Length)

' 设置当前流的位置为流的开始

stream.Seek(0, SeekOrigin.Begin)

Return bytes

End Function

Public Function BytesToStream(ByVal bytes() As Byte) As Stream

Dim stream As Stream =  New MemoryStream(bytes)

Return stream

End Function

Stream 和 文件之间的转换

Public Sub StreamToFile(ByVal stream As Stream, ByVal fileName As String)

' 把 Stream 转换成 byte()

Dim bytes() As Byte =  New Byte(stream.Length) {}

stream.Read(bytes, 0, bytes.Length)

' 设置当前流的位置为流的开始

stream.Seek(0, SeekOrigin.Begin)

' 把 byte()写入文件

Dim fs As FileStream =  New FileStream(fileName,FileMode.Create)

Dim bw As BinaryWriter =  New BinaryWriter(fs)

bw.Write(bytes)

bw.Close()

fs.Close()

End Sub

从文件读取Stream

Public Function FileToStream(ByVal fileName As String) As Stream

'打开文件

Dim fileStream As FileStream

fileStream = New FileStream(fileName,FileMode.Open,FileAccess.Read,FileShare.Read)

'读取文件的 byte()

Dim bytes() As Byte =  New Byte(fileStream.Length) {}

fileStream.Read(bytes, 0, bytes.Length)

fileStream.Close()

'把 byte()转换成 Stream

Dim stream As Stream =  New MemoryStream(bytes)

Return stream

End Function

3， bitmap和base64之间的转换

• /**
• * bitmap转为base64
• * @param bitmap
• * @return
• */
• public static String bitmapToBase64(Bitmap bitmap) {
• String result = null;
• ByteArrayOutputStream baos = null;
• try {
• if (bitmap != null) {
• baos = new ByteArrayOutputStream();
• bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
• baos.flush();
• baos.close();
• byte[] bitmapBytes = baos.toByteArray();
• result = Base64.encodeToString(bitmapBytes, Base64.DEFAULT);
• }
• } catch (IOException e) {
• e.printStackTrace();
• } finally {
• try {
• if (baos != null) {
• baos.flush();
• baos.close();
• }
• } catch (IOException e) {
• e.printStackTrace();
• }
• }
• return result;
• }
• /**
• * base64转为bitmap
• * @param base64Data
• * @return
• */
• public static Bitmap base64ToBitmap(String base64Data) {
• byte[] bytes = Base64.decode(base64Data, Base64.DEFAULT);
• return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);