将保存在数据库中的图片信息生成缩略图的问题，请大家指导！
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悬赏园豆：20
[已解决问题]
解决于 2009-05-20 09:54
<h1 class="postTitle">我使用的是vs2003 VB.net.</h1>
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<p>我想把保存在数据库中的图片文件，提取后，生成缩略图显示在网页上，以下是我的代码：</p>
<p> Dim con As New SqlClient.SqlConnection<br /> Dim cmd As New SqlClient.SqlCommand<br /> Dim fjnr() As Byte<br /> con.ConnectionString = dbconstring<br /> cmd.Connection = con<br /> con.Open()<br /> cmd.CommandText = "select fjnr from L_fj where id = " & fjid<br /> fjnr = Convert.FromBase64String(cmd.ExecuteScalar())<br /> Dim sfj As New System.IO.MemoryStream(fjnr)<br /> img = System.Drawing.Image.FromStream(sfj,True)</p>
<p>其中fjid是图片的id号，在执行Dim sfj As New System.IO.MemoryStream(fjnr)时报错，image对象生成失败。</p>
<p>请各位帮忙指教。</p>
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最佳答案
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cmd.CommandText = "select fjnr from L_fj where id = " & fjid
fjnr = Convert.FromBase64String(cmd.ExecuteScalar())
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是不是 FromBase64String 有问题?
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Dim sfj As New System.IO.MemoryStream(fjnr)
img = System.Drawing.Image.FromStream(sfj,True)
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是不是该用 Dim sfj As New System.IO.MemoryStream(fjnr, 0, fjnr.length) ?
我用 c#，乍看上去可能是二进制流的读取问题，但因为不懂 vb，所以不能确定，呵呵。
