Press Power button Twice to send SMS

问题:

I have written an app in which the user can send messages whenever they press a button given in the activity, and it works fine for me, but now my target is to send SMS by using double press on power button.

but I don't have any idea, how to do that ?

   Send SMS by using double press on power button

below is the code, which I am using to send SMS:

 btnPanic.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String message = "My current location is:" + "\t" + currentLocation ;

            String phoneNo = editContacts.getText().toString();

            StringTokenizer st=new StringTokenizer(phoneNo,",");
            while (st.hasMoreElements())
            {
                String tempMobileNumber = (String)st.nextElement();
                if(tempMobileNumber.length()>0 && message.trim().length()>0) {
                    sendSMS(tempMobileNumber, message);
            }
            else 
            {
              Toast.makeText(getBaseContext(), 
                "Please enter both phone number and message.", 
                 Toast.LENGTH_SHORT).show();
            }
        }
    }
});

回答1:

I can give you Idea about how can you implement this well it's hardcoded.

Pardon me if I went wrong.!!

This is kind of conversion of key event to double click.

So here I am considering key pressed twice as Double click

First see key event of power button.

1

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(KeyEvent.KEYCODE_POWER == event.getKeyCode()){
      if(time interval is less)//Consider as double click
       //code to send messages
        else            //Consider as single click
       //nothing to do   
    }
    return super.onKeyDown(keyCode, event);
}

2. You should use System.currentTimeMillis() to find time of two clicks in which Double click can be validated.

Try Doubleclick and record time and do it many times as you will get precise time.

So in short you have to first find how much maximum time allowed beetween two click which is considered as doubleClick.

So that we can differentiate beetween click and doubleclick.

3 So at key event you need to do this

long l=0;//at start not in key event handler

if(l=0){l=System.currentTimeMillis();}//clicked first time
else{l=System.currentTimeMillis()-l;}//second time

And you are done use this long values to decide is it click or double click.

回答2:

    public boolean onKeyDown(int keyCode, KeyEvent event) {
     if (event.getKeyCode() == KeyEvent.KEYCODE_POWER) {
    // do what you want with the power button

        String message = "My current location is:" + "\t" + currentLocation ;

        String phoneNo = editContacts.getText().toString();

        StringTokenizer st=new StringTokenizer(phoneNo,",");
        while (st.hasMoreElements())
        {
            String tempMobileNumber = (String)st.nextElement();
            if(tempMobileNumber.length()>0 && message.trim().length()>0) {
                sendSMS(tempMobileNumber, message);
        }
        else 
        {
          Toast.makeText(getBaseContext(), 
            "Please enter both phone number and message.", 
             Toast.LENGTH_SHORT).show();
        }
    return true;
}
return super.onKeyDown(keyCode, event);

}

回答3:

This is probably what you are looking for http://www.nkonecny.com/blog/2012/02/16/capture-power-button-keypress/

same thing you can check twice since you want the power button to be pressed twice so I think it will serve your purpose.