【IT168 技术】编者按：java事件机制包括三个部分：事件、事件监听器、事件源。事件一般继承自java.util.EventObject类，封装了事件源对象及跟事件相关的信息。事件监听器能够实现java.util.EventListener接口,注册在事件源上,当事件源的属性或状态改变时,取得相应的监听器调用其内部的回调方法。事件源为事件发生的地方。作者所讲述为Form的Control Keyevent。

　　一、Form的KeyEvent

　　image

　　KeyCode:

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
        if ((e.Modifiers == Keys.Control) && (e.KeyCode == Keys.Z))
        {
            this.cancelHandler();
        }
        else if ((e.Modifiers == Keys.Control) && (e.KeyCode == Keys.S))
        {
            this.saveHandler();
        }
        else
            e.Handled = true;
    }

　　二、Control’s KeyEvent

　　检测输入control的字符的正确性。

    private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar == 'b')
            mPwFlag[0] = e.KeyChar;
        if (e.KeyChar == 'a')
            mPwFlag[1] = e.KeyChar;
        if (e.KeyChar == 't')
            mPwFlag[2] = e.KeyChar;
        if (e.KeyChar == '1')
            mPwFlag[0] = e.KeyChar;
        if (e.KeyChar == '2')
            mPwFlag[1] = e.KeyChar;
        if (e.KeyChar == '3')
            mPwFlag[2] = e.KeyChar;

        if (mPwFlag[0] == 'b' && mPwFlag[1] == 'a' && mPwFlag[2] == 't')
        {
            mPwFlag[0] = '0';
            mPwFlag[1] = '0';
            mPwFlag[2] = '0';
            BatCreateTopic bct = new BatCreateTopic(this);
            this.button3.Visible = true;
            bct.ShowDialog(this);
        }
    }