核心: this.errorProvider1.SetError(this.username, "Please input your username!");
bool flag = true;
#region errorproviderif (username.Text.Trim() == string.Empty)
{
this.errorProvider1.SetError(this.username, "Please input your username!");
flag = false;
}
else if (password.Text.Trim() == string.Empty)
{
this.errorProvider1.SetError(this.password, "Password can not be empty!");
flag = false;
}
else if (password.Text.Length != 8)
{
this.errorProvider1.SetError(this.password, "The length of Password must be eight!");
this.password.Text = "";
flag = false;
}