在datalist - asp.net中显示默认图像或以字节为单位的图像

protected void dataList_ItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DataRowView drv = e.Item.DataItem as DataRowView;
        string imagePath = drv["ImagePath"].ToString(); // 从数据源中获取图像路径
        Image img = e.Item.FindControl("imgThumbnail") as Image; // 获取Image控件
        if (string.IsNullOrEmpty(imagePath))
        {
            img.ImageUrl = "DefaultImage.jpg"; // 设置默认图像路径
        }
        else
        {
            img.ImageUrl = imagePath;
        }
    }
}

protected void dataList_ItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DataRowView drv = e.Item.DataItem as DataRowView;
        byte[] imageData = (byte[])drv["ImageData"]; // 从数据源中获取字节数据
        Image img = e.Item.FindControl("imgThumbnail") as Image; // 获取Image控件
        if (imageData != null && imageData.Length > 0)
        {
            string base64String = Convert.ToBase64String(imageData); // 将字节数据转换为Base64编码的字符串
            img.ImageUrl = "data:image/jpeg;base64," + base64String; // 设置Image控件的ImageUrl属性
        }
        else
        {
            img.ImageUrl = "DefaultImage.jpg"; // 设置默认图像路径
        }
    }
}