奇怪的错误。我有以下代码。无法更改标签文字
private void connectButton_Click(object sender, EventArgs e)
{
statusLabel.Text = "Connecting...";
statusLabel.ForeColor = Color.Green;
serverNameBox.Enabled = false;
databaseNameBox.Enabled = false;
connectButton.Enabled = false;
conn = new SqlConnection("server=" + serverNameBox.Text + ";Trusted_Connection=yes;database=" + databaseNameBox.Text + ";connection timeout=3");
try
{
conn.Open();
}
catch (Exception ex)
{
statusLabel.Text = "Connection Failed";
statusLabel.ForeColor = Color.DarkRed;
MessageBox.Show("Connection Failed. Error message below:\n" + ex.Message);
serverNameBox.Enabled = true;
databaseNameBox.Enabled = true;
connectButton.Enabled = true;
return;
}
statusLabel.Text = "Connected Successfully";
statusLabel.ForeColor = Color.DarkGreen;
serverNameBox.Enabled = true;
connectButton.Enabled = true;
conn.Close();
UpdateTraders();
UpdateTransactions();
}
“连接成功”和“连接失败”都工作得不错。但是,statusLabel永远不会更改为“正在连接”。 statusLabel.Text的默认值是“”(无)。
这是怎么回事?
也可以使用'DbConnection.OpenAsync()'方法(如果使用Framework 4.5)。 –