上传图片并保存视图状态下的文件流

Question

protected void upload_Click(object sender, EventArgs e) 
{ 
    if (Upload.Value !="") 
    { 
     System.IO.Stream fs = Upload.PostedFile.InputStream; 
     img_uploadStream = Upload.PostedFile.InputStream; 
     System.IO.BinaryReader br = new System.IO.BinaryReader(fs); 
     Byte[] bytes = CreateThumbnail(br.ReadBytes((Int32)fs.Length),150); 
     string base64String = Convert.ToBase64String(bytes, 0, bytes.Length); 
     imageField.Src = String.Format("data:{0};base64,{1}", "image/jpeg", base64String); 
    } 
} 

上传图片后，Upload.PostedFile.InputStream设置为空值。 我想将此输入流保存到asp.net视图状态以重用。要使用

ViewState["ImageStream"]=Upload.PostedFile.InputStream; 

然后你就可以在页面内得到您的视图状态的任何地方：

Answer 1

您可以使用此代码

public Byte[] YourImage 
{ 
get 
{ 
if(ViewState["Key"] != null) 
{ 
return (Byte[]) ViewState["Key"]; 
} 
return null; 
} 

set 
{ 
    ViewState["Key"] = value; 
} 
} 

Answer 2

设置的ViewState内upload_Click

System.IO.Stream fstream=(System.IO.Stream)ViewState["ImageStream"];