private void btn_Login_Click(object sender, EventArgs e) { try { this.backgroundWorker1.RunWorkerAsync(); // 运行 backgroundWorker 组件 JingDu form = new JingDu(this.backgroundWorker1, "后台验证中"); // 显示进度条窗体 form.ShowDialog(this); form.Close(); bool Loginpd = cals.Login(txt_User.Text.Trim(), txt_pwd.Text.Trim()); if (Loginpd) { MessageBox.Show("登陆成功!"); this.DialogResult = System.Windows.Forms.DialogResult.OK; this.Close(); } else { MessageBox.Show("登录失败!原因:账号或密码错误"); } } catch (Exception ex) { MessageBox.Show("登录失败!原因:找不到账号或密码!"); } }