C# Winform 密码框

Question

在textBox中按下一个健就显示该健  放掉就显示*  如**8 输入下一个的时候上一个就显示*
   在线等  谢谢！

Answer 1

类似这样，自己完善吧        private void textBox3_KeyDown(object sender, KeyEventArgs e)
        {
            if (textBox3.Tag == null)
            {
                textBox3.Tag = e.KeyCode.ToString();
            }
            else
            {
                string str = "";
                str = str.PadLeft(textBox3.Tag.ToString().Length, '*') + e.KeyCode.ToString();
                textBox3.Text = str;
                textBox3.Tag = textBox3.Tag.ToString() + e.KeyCode.ToString();                
            }
        }

Answer 2

就是文本框事件里，将用户输入的字符用*号replace掉，自己声明一个字符串来保存用户的实际输入

Answer 3

定义一个string变量用来存真正的密码，然后在textbox事件里，将密码前n-1位replace成"*",只显示最后一位。当textbox失去焦点的时候，所有的密码都显示"*"。

Answer 4

    public class MyTextBox : TextBox
    {
        private Timer _Timer;        public MyTextBox()
        {
            this.KeyUp += TextBoxKeyUp;            _Timer = new Timer();           
            _Timer.Tick += Tick;
            _Timer.Interval = 200;
        }        private void TextBoxKeyUp(object sender, EventArgs e)
        {
            _Timer.Start();
        }        private void Tick(object sender, EventArgs e)
        {
            _Timer.Stop();
            Text = new String('*', Text.Length);
            this.SelectionStart = Text.Length;
        }
    }原来的值怎么保存呢?

Answer 5

很好实现的，
在textChaned事件中先将无效值都过滤掉，
输入的时候只保留最后一位，其它都替换成"*",
密码没多长，这个效率可以忽略，
当文本框没有焦点时，全部都替换成"*"

Answer 6

我说简单是我曾经实现过类似的，
我说了先要过滤无效字符和操作，
只有当光标在最后一个字符，backspace才可用，
就是说只能删除最后一个字符，
其它操作包括复制，粘贴，剪切，从中间插入等都是无效的

Answer 7

 StringBuilder sb = new StringBuilder();
        private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if (textBox1.Text.Trim().Length > 0)
            {
                string s=textBox1.Text.Substring(textBox1.Text.Length-1,1);
                sb.Append(s);
                
              textBox1.Text=textBox1.Text.Trim().Replace(s,"*");
              textBox1.SelectionStart = textBox1.Text.Length;
            }
        }

Answer 8

可以用文本框的key_up，与key_down两个事件配合着来完成。也可以用字符串的函数操作来实现。具体做法会有很多。具体做法，自己解决了，才会体会到解决问题的兴奋。

Answer 9

随便写的一个，轻点喷撒public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            textBox1.ContextMenu = new ContextMenu();            textBox1.KeyPress += new KeyPressEventHandler(textBox1_KeyPress);        }
        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (flag == 1)
            {
                flag = 0;
                return;
            }
            flag++;            if (textBox1.SelectionStart == textBox1.Text.Length)
            {
                cando = true;
            }            if (textBox1.SelectionStart < textBox1.Text.Length || (int)e.KeyChar == 22 || (int)e.KeyChar >= 112 && e.KeyChar == 115 || e.KeyChar == 24 || e.KeyChar == 3 && e.KeyChar == 8 && e.KeyChar == 13)
            {
                e.Handled = true;
                cando = false;
            }            if ((int)e.KeyChar == 8 && textBox1.Text.Length > 0)
            {                int sta = sb.ToString().Length - 1;
                if (sta >= 0)
                    sb.Remove(sta, 1);
                isback = true;
            }
            else
            {
                isback = false;
            }        }
        bool cando = true;
        int flag = 0;
        bool isback = false;
        StringBuilder sb = new StringBuilder();
        private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if (!cando)
            {
                return;
            }            if (textBox1.Text.Trim().Length > 0 && !isback)
            {                isback = false;
                string s = textBox1.Text.Substring(textBox1.Text.Length - 1, 1);
                sb.Append(s);                textBox1.Text = textBox1.Text.Trim().Replace(s, "*");
                textBox1.SelectionStart = textBox1.Text.Length;
                MessageBox.Show(sb.ToString());
            }
            else
            {
                MessageBox.Show(sb.ToString());
            }
        }
    }

Answer 10

我去，csdn不及时更新，害我发了2次回复，

Answer 11

尼玛。都怎么回答的。控件有个属性textBox1.PasswordChar = '*';

Answer 12

看错了。对不住大家textBox1.PasswordChar = '\0';
可以还原
可以计时开启属性
或离开焦点

Answer 13

21楼的s不能输
以及只处理了只能一次输对密码 不能修改
我对其中进行了部分修改
里面还是有蛮多bug的因为找到其他方法了 就没处理了  先把这代码贴下
 /// <summary>
        /// 用于记录密码
        /// </summary>
        private StringBuilder StrPassword = new StringBuilder();
        private void password_KeyDown(object sender, KeyEventArgs e)
        {
            if (password.Text.Length > 0)
            {
                if (e.KeyValue == 46)
                {
                    if (password.SelectionStart >= password.Text.Length)
                    {
                        return;
                    }
                    else
                    {
                        isDel = true;
                        if (password.SelectionStart != 0)
                        {
                            mouseStart = password.SelectionStart;
                        }
                        else
                        {
                            mouseStart = 0;
                        }
                        int leg = password.SelectionLength == 0 ? 1 : password.SelectionLength;
                        try
                        {
                            password.Text = password.Text.Remove(mouseStart, leg - 1);
                            StrPassword.Remove(mouseStart, leg);
                        }
                        catch
                        {
                        }
                        password.SelectionStart = mouseStart;
                    }
                }
                else
                {
                    if ((int)e.KeyValue == 22 || e.KeyValue == 24 || e.KeyValue == 3 && e.KeyValue == 8 && e.KeyValue == 13)
                    { }
                    else if (password.SelectionLength > 0)
                    {
                        isResetPWD = true;
                        resetPWD = password.SelectionLength;
                        mouseStart = password.SelectionStart;
                        StrPassword.Remove(mouseStart, resetPWD);
                    }
                    isDel = false;
                }
            }
        }
        bool isResetPWD = false;//选择部分密码时输入密码
        bool isDel = false;
        int mouseStart = 0;
        int resetPWD = 0; //选中部分密码时选中的长度
        bool cando = true;
        bool isback = false; //是否按的是后退
        private void password_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (password.SelectionStart == password.Text.Length)
            {
                cando = true;
            }            if ((int)e.KeyChar == 22 || e.KeyChar == 24 || e.KeyChar == 3 && e.KeyChar == 8 && e.KeyChar == 13)
            {
                e.Handled = true;
                cando = false;
            }
            if (e.KeyChar == 8)
            {
                if (password.SelectionStart == 0 && password.SelectionLength == 0)
                {
                    return;
                }
                else
                {
                    isback = true;
                    mouseStart = password.SelectionStart;
                    try
                    {
                        if (password.SelectionLength == 0)
                        {
                            password.Text = password.Text.Remove(mouseStart - 1, 1);
                            StrPassword.Remove(mouseStart - 1, 1);
                            password.SelectionStart = mouseStart - 1;
                        }
                        else
                        {
                            password.Text = password.Text.Remove(mouseStart, password.SelectionLength);
                            StrPassword.Remove(mouseStart, password.SelectionLength);
                            password.SelectionStart = mouseStart;
                        }
                    }
                    catch
                    {
                    }                }
            }
            else
            {                isback = false;
            }
        }        private void password_KeyUp(object sender, KeyEventArgs e)
        {
            if (password.Text == "")
            {
                StrPassword.Length = 0;
            }
        }        private void password_TextChanged(object sender, EventArgs e)
        {
            if (!cando)
            {
                return;
            }
            if (password.Text.Trim().Length > 0 && !isback && !isDel)
            {
                isback = false;
                isDel = false;
                if (isResetPWD)
                {
                    string ss = password.Text.Substring(mouseStart, 1);
                    if (ss != "*")
                    {
                        string endstr = StrPassword.ToString().Insert(mouseStart, ss);
                        StrPassword = new StringBuilder(endstr);
                    }
                    if (password.Text.Length > 1)
                    {
                        string sstart = password.Text.Substring(0, 1);
                        if (sstart != "*")
                        {
                            StrPassword.Append(ss);
                            password.Text = password.Text.Trim().Replace(sstart, "*");
                        }
                    }
                    isResetPWD = false;
                }
                string s = password.Text.Substring(password.Text.Length - 1, 1);
                if (s != "*")
                    StrPassword.Append(s);
                if (password.Text.Length > 1)
                {
                    string sstart = password.Text.Substring(0, 1);
                    if (sstart != "*")
                    {
                        StrPassword.Append(s);
                        password.Text = password.Text.Trim().Replace(sstart, "*");
                    }
                }
                password.Text = password.Text.Trim().Replace(s, "*");                password.SelectionStart = password.Text.Length;
            }
        }