基本上...当用户接受或拒绝朋友请求时,它应该删除用户的名字,接受和拒绝按钮,但它只删除用户的名字和拒绝按钮。我不明白。代码:
private void loadFriendRequests()
{
using (SqlConnection connection = new SqlConnection(con))
{
using (SqlCommand cmd = new SqlCommand(@"Select IDRequest, UserFirstName, UserLastName, FriendEmail From PendingRequests Where FriendEmail = @fe", connection))
{
connection.Open();
cmd.Parameters.AddWithValue("@fe", Properties.Settings.Default.Email);
using (SqlDataReader dr = cmd.ExecuteReader())
{
int i = 0;
while (dr.Read())
{
i++;
foreach (object request in i.ToString())
{
Label userName = new Label();
Button accept = new Button();
Button reject = new Button();
accept.Text = "Accept";
reject.Text = "Reject";
int idRequest = Convert.ToInt32(dr["IDRequest"]);
userName.Text = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(dr["UserFirstName"].ToString() + " " + dr["UserLastName"].ToString());
userName.Tag = idRequest;
accept.Tag = idRequest;
reject.Tag = idRequest;
accept.Click += Accept_Click;
reject.Click += Reject_Click;
friendRequestPanel.Controls.Add(userName);
friendRequestPanel.Controls.Add(accept);
friendRequestPanel.Controls.Add(reject);
}
}
}
}
}
Requests.Start();
}
private void Reject_Click(object sender, EventArgs e)
{
Button c = sender as Button;
int idRequest = Convert.ToInt32(c.Tag);
var ctrls = friendRequestPanel.Controls
.Cast<Control>()
.Where(x =>
Convert.ToInt32(x.Tag) == idRequest);
foreach (Control ct in ctrls)
{
friendRequestPanel.Controls.Remove(ct);
ct.Dispose();
}
updateFriendRequestDatabase(2);
}
private void Accept_Click(object sender, EventArgs e)
{
Button c = sender as Button;
int idRequest = Convert.ToInt32(c.Tag);
var ctrls = friendRequestPanel.Controls
.Cast<Control>()
.Where(x => x.Tag != null &&
Convert.ToInt32(x.Tag) == idRequest);
foreach (Control ct in ctrls)
{
friendRequestPanel.Controls.Remove(ct);
ct.Dispose();
}
updateFriendRequestDatabase(1);
}
图片:GUI
点击任何按钮时:GUI
为什么不删除“接受”按钮?
答案 0 :(得分:1)
您正在循环中更改集合。要解决此问题,您可以在找到控件的条件的末尾调用ToList
,并循环结果。这样,您循环遍历与要更改的集合不同的列表:
var ctrls = friendRequestPanel.Controls.Cast<Control>()
.Where(Convert.ToInt32(x.Tag) == idRequest)
.ToList(); //<--- Creates a new List<Control>
foreach (Control ct in ctrls)
{
friendRequestPanel.Controls.Remove(ct);
ct.Dispose();
}