C#编写winform修改用户

1、以XML的方式首先连接数据库，具体连接方式请参考相关文档或小编的上一篇《C#编写winform新增用户》

2、检查要修改密码的用户是否存在。

3、检查输入的旧密码是否正确，这样是防止别人随意去更改他人帐号密码。

4、新密码验证，确保user输入的密码正确。

5、Update 数据库表，并做相关提示。update Employee set pwd ='" + newpwd + "'where User_id='" + textBox6.Text.Trim() + "'", conn

6、附上完整代码:private void button2_Click(object sender, EventArgs e) { try { SqlConnection conn = new SqlConnection(Read_Xml(Application.StartupPath + "\\Sqlconnection.xml")); conn.Open(); SqlCommand cmd3 = new SqlCommand("select count(*) from Employee where User_id='" + textBox6.Text.Trim() + "'", conn); int b = (int)cmd3.ExecuteScalar(); if (b == 1) { SqlCommand cmd4 = new SqlCommand("select pwd from Employee where User_id='" + textBox6.Text.Trim() + "'", conn); string c = cmd4.ExecuteScalar().ToString(); string oldpwd = textBox7.Text.Trim(); string newpwd = textBox8.Text.Trim(); string dnewpwd = textBox9.Text.Trim(); if ((b == 1) && (c == oldpwd) && (newpwd == dnewpwd)) { SqlCommand cmd5 = new SqlCommand("update Employee set pwd ='" + newpwd + "'where User_id='" + textBox6.Text.Trim() + "'", conn); int k = (int)cmd5.ExecuteNonQuery(); if (k > 0) { MessageBox.Show("密码修改成功！", "提示"); } else { MessageBox.Show("密码修改失败！", "提示"); } } else { MessageBox.Show("新旧密码填写错误，请检查！", "提示"); } } else { MessageBox.Show("用户名不存在！", "提示"); } conn.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }