在ASP.NET中將二進制數據轉換爲圖像控件

Question

我的數據庫中有圖像的二進制數據，我想在ASP.NET的圖像控件中顯示它。怎麼樣？如果不可能，請找到另一種方法將其保存在數據庫中，並將其顯示在圖像控件中。

Answer 1

創建一個普通的HTML img元素，像這樣：

<img runat="server" id="image" /> 

而且在code behind做到這一點：

image.src = "data:image/png;base64," + Convert.ToBase64String(imageBytes); 

凡imageBytes是byte[] 。

你完成了。圖像將被顯示。

Answer 2

在一個通用處理器（ashx的）：

public class ImageHandler : IHttpHandler 
     { 

      public void ProcessRequest(HttpContext context) 
      { 

        if(!string.IsNullOrEmpty(context.Request.QueryString["ImageId"])){ 
        try 
        { 
         string ImageId = context.Request.QueryString["ImageId"].ToString(); 
         ImageDataModel idm = new ImageDataModel(); 
         byte[] ImageData = idm.getImageData(ImageId); 

         context.Response.ContentType = "image/JPEG"; 
         context.Response.OutputStream.Write(ImageData, 0, ImageData.Length); 


        } 

Answer 3

最有可能的圖像被存儲在數據庫中的字節數組。如果是這樣，那麼你可以使用這個：

public static System.Drawing.Image ByteArrayToImage(byte[] bArray) 
{ 
    if (bArray == null) 
     return null; 

    System.Drawing.Image newImage; 

    try 
    { 
     using (MemoryStream ms = new MemoryStream(bArray, 0, bArray.Length)) 
     { 
      ms.Write(bArray, 0, bArray.Length); 
      newImage = System.Drawing.Image.FromStream(ms, true); 
     } 
    } 
    catch (Exception ex) 
    { 
     newImage = null; 

     //Log an error here 
    } 

    return newImage; 
} 

Answer 4

public Byte[] Ret_image(Int32 id) 
{ 
    SqlCommand cmd = new SqlCommand(); 
    cmd.CommandText = "select * from tbimage where imageid=@id"; 
    cmd.Connection = con; 
    cmd.Parameters.Add("@id", SqlDbType.Int).Value = id; 
    SqlDataReader dr = cmd.ExecuteReader(); 
    dr.Read(); 
    Byte[] ar = (Byte[])(dr[1]); 
    dr.Close(); 
    cmd.Dispose(); 
    return ar; 
} 

Answer 5

protected void Button2_Click(object sender, EventArgs e) 
{ 
    Byte[] ar = Ret_image(Convert.ToInt32(TextBox2.Text)); 
    String st = Server.MapPath("abc.jpg"); 
    FileStream fs = new FileStream(st, FileMode.Create, FileAccess.Write); 
    fs.Write(ar, 0, ar.Length); 
    fs.Close(); 
    Image1.ImageUrl = "abc.jpg";   
} 

使用此事件點擊按鈕來獲取圖像，並在這裏調用Ret_Image方法。

Answer 6

SqlConnection con = new SqlConnection(); 
string _path; 
Using SYstem.IO; 
Using System.Data.SQLClient; 

//convert Image to binary and save in DB 

private void button1_Click(object sender, EventArgs e) 
{ 
    if (openFileDialog1.ShowDialog() == DialogResult.OK) 
    { 
     _path = openFileDialog1.FileName; 
     InsertInSQL(_path); 
    } 
} 

private void InsertInSQL(string _path) 
{ 
    con.ConnectionString = Pic.Properties.Settings.Default.ConnectionS; 
    string strQ = "insert into dbo.PicTBL(Pic)values(@p)"; 
    SqlCommand command = new SqlCommand(strQ,con); 
    command.Parameters.AddWithValue("@p",ImageToBinary(_path)); 
    con.Open(); 
    command.ExecuteNonQuery(); 
    con.Close(); 
}  

public static byte[] ImageToBinary(string _path) 
{ 
    FileStream fS = new FileStream(_path, FileMode.Open, FileAccess.Read); 
    byte[] b = new byte[fS.Length]; 
    fS.Read(b, 0, (int)fS.Length); 
    fS.Close(); 
    return b; 
} 

//Convert Binary to imge and save in a folder 
private void button1_Click_1(object sender, EventArgs e) 
{ 
    DataTable dt = Rimage(); 
    foreach (DataRow row in dt.Rows) 
    { 
     byte[] b = (byte[])row["Pic"]; 
     Image img = BinaryToImage(b); 
     img.Save("D:\\NewFolder\\" + row["ID"].ToString() + ".jpg"); 
    } 
} 

private Image BinaryToImage(byte[] b) 
{ 
    if (b == null) 
     return null; 

    MemoryStream memStream = new MemoryStream(); 
    memStream.Write(b, 0, b.Length); 

    return Image.FromStream(memStream); 
} 

private DataTable Rimage() 
{ 
    con.ConnectionString = Pic.Properties.Settings.Default.ConnectionS; 
    SqlCommand cmd = new SqlCommand(); 
    cmd.CommandText = "select * from dbo.PicTBL"; 
    cmd.Connection = con; 
    SqlDataAdapter adp = new SqlDataAdapter(cmd); 
    DataTable dt = new DataTable(); 
    con.Open(); 
    adp.Fill(dt); 

    return dt; 
}