具有图像路径的C＃datagridview绑定源（如果不存在）

Question

Hello i have one question, im getting data to datagridview with bindingSource, my code is bellow;

string query= "SELECT a.id as id1,a.id2, a.system_id, CONCAT(b.path,a.image) as photo ,b.id as id5,b.name,b.path  FROM users a INNER JOIN systems b ON a.system_id=b.id  order by a.id DESC LIMIT 20";
            using (MySqlCommand cmd = new MySqlCommand(query, conn))
            {
                MySqlDataAdapter da = new MySqlDataAdapter(cmd);
                var dt = new System.Data.DataTable();
                da.Fill(dt);
                bindingSource1.DataSource = dt.Rows.Cast<DataRow>().Select(p => new aclass() { id = (p["id1"].ToString()),  Photo= Image.FromFile(p["photo enter code here"].ToString()) }).ToList();
                conn.Close();


            }

This function getting image path and adding to list and showing in datagridview with photo, but my problem is if this photo is deleted not getting showing error,how to make if this photo is deleted adding one photo avatar default. If exist photo showing original photo. Thnks

Answer 1

You need to check if the file exists first and then either load it from the path or from the avatar path. You can use these helper functions:

private string LoadImage(string imagePath) {
  return Image.FromFile(MapImagePath(imagePath));
}

private string MapImagePath(string imagePath) {
  if (string.IsNullOrEmpty(imagePath))
    imagePath = GetNoImagePath();
  else {
    if (!File.Exists(imagePath))
      imagePath = GetNoImagePath();
  }
  return imagePath;
}

private string GetNoImagePath() {
  return "D:\ProjectFolder\Images\NoImage.png";
}

And now you can call them from your code like this:

var data = dt.Rows.Cast<DataRow>().Select(p => new aclass() {
  id = (p["id1"].ToString()),
  Photo = LoadImage(p["photo enter code here"].ToString())
}).ToList();

Note: Of course, you can make the path to the avatar a constant instead of a function. The function could be useful if you have several avatars and you want to return one of them based on some conditions.

Answer 2

You need to check if the file exists first and then either load it from the path or from the avatar path.

string avaterPath=@"D:\Images\NoImage.png";
string query= "SELECT a.id as id1,a.id2, a.system_id, CONCAT(b.path,a.image) as photo ,b.id as id5,b.name,b.path  FROM users a INNER JOIN systems b ON a.system_id=b.id  order by a.id DESC LIMIT 20";
            using (MySqlCommand cmd = new MySqlCommand(query, conn))
            {
                MySqlDataAdapter da = new MySqlDataAdapter(cmd);
                var dt = new System.Data.DataTable();
                da.Fill(dt);
                bindingSource1.DataSource = dt.Rows.Cast<DataRow>().Select(p => new aclass() { id = (p["id1"].ToString()),  Photo=File.Exists(p["photo enter code here"].ToString())? Image.FromFile(p["photo enter code here"].ToString()):Image.FromFile(avaterPath) }).ToList();
                conn.Close();


            }

Answer 3

thanks everyone, this is my solution;

 string avaterPath=@"D:\Images\NoImage.png";
string query= "SELECT a.id as id1,a.id2, a.system_id, CONCAT(b.path,a.image) as photo ,b.id as id5,b.name,b.path  FROM users a INNER JOIN systems b ON a.system_id=b.id  order by a.id DESC LIMIT 20";
            using (MySqlCommand cmd = new MySqlCommand(query, conn))
            {
                MySqlDataAdapter da = new MySqlDataAdapter(cmd);
                var dt = new System.Data.DataTable();
                da.Fill(dt);
                bindingSource1.DataSource = dt.Rows.Cast<DataRow>().Select(p => new aclass() { id = (p["id1"].ToString()),  Photo=File.Exists(p["photo enter code here"].ToString())? Image.FromFile(p["photo enter code here"].ToString()):Image.FromFile(avaterPath) }).ToList();
                conn.Close();


            }