A solution to the control of input characters in a TextBox

Solution | Control we know that in C #, TextBox controls have KeyPress, KeyUp, and KeyDown events to control the input characters, but as you can see, these events have a certain flaw in the control of the input characters, if you use the Chinese input method, So many of the characters you don't want to enter can also be entered. These days to do the procedure, this problem, my solution is very simple, since these three events no longer work, then I use the TextBox control in the moment can occur textchanged events, in order to expect to do something in this event, to achieve the purpose of controlling characters. Nonsense is not much to say, I will control the input characters for the number of code paste out, I hope everyone to correct, if it can be beneficial to you, I will be more happy.


Private System.Windows.Forms.TextBox TextBox1;
private string text;
Public Form1 ()
{
Text = TextBox1.Text;
}
private void textBox1_TextChanged (object sender, System.EventArgs e)
{
int len = text. Length;
if (Len < textBox1.Text.Length)
{
int index = TEXTBOX1.TEXT.INDEXOF (Text);
char C = (TextBox1.Text.Remove (index,text). Length)) [0];
if (C.compareto (' 0 ') < 0| |c.compareto (' 9 ') >0)
{
TextBox1.Text = Text;
Textbox1.selectionstart = text. Length;
}
}
Text = TextBox1.Text;

}