本文給出一個用 C# 編程實現讀寫 Binary 的實例代碼對於初學者來說是個不可多得的參考性文章……
以下是引用片段
//返回blob數據
public MemoryStream getBlob(string SQL)
{
try
{
Db_Conn();
cmd = new OleDbCommand(SQL Conn);
cmdCommandType = CommandTypeText;//是sql
OleDbDataReader Rs = cmdExecuteReader();
if (RsRead()) //循環到下一條記錄
{
if (!(RsGetValue() is SystemDBNull))
{
byte[] image_bytes = (byte[])RsGetValue();
MemoryStream ms = new MemoryStream(image_bytes);
return ms;
}
else
return null;
}
else
return null;
}
finally
{
thisclose();
}
}
//設置blob
public bool SetBlob(string SQL MemoryStream Ms)
{
try
{
Db_Conn();
cmd = new OleDbCommand(SQL Conn);
cmdCommandType = CommandTypeText;//是sql
int n=ConvertToInt(MsLengthToString());
MsPosition = ;
byte[] pReadByte = new Byte[n];
MsRead(pReadByte n);
cmdParametersAdd(BLOB OleDbTypeBinary)Value = pReadByte;
cmdExecuteNonQuery();
return true;
}
catch (Exception ex)
{
MessageBoxShow(錯誤:因 + exMessage + 無法執行: + SQL);
return false;
}
finally
{
thisclose();
}
}
調用 getBlob
以下是引用片段
String sqlStr = select content from dp where id= + ID;
//content為dp中的BLOB字段ID為主鍵
MemoryStream ms = DBClassgetBlob(sqlStr);
if (ms == null)
richTextBoxClear();
else
{
if (msLength > )
{
msPosition = ;
try
{
richTextBoxLoadFile(ms RichTextBoxStreamTypeRichText);
}catch{
richTextBoxLoadFile(ms RichTextBoxStreamTypePlainText);
}
}else
richTextBoxClear();
}
調用setBlob
以下是引用片段
String sqlStr = update dp set content=:BLOB where id= + ID;
MemoryStream ms = new MemoryStream();
richTextBoxSaveFile(ms RichTextBoxStreamTypeRichText);
if (!DBClassSetBlob(sqlStr ms))
{
MessageBoxShow(保存失敗);
}
From:http://tw.wingwit.com/Article/program/net/201311/13757.html
