title: Button onclick listener must be displayed in edittext
body: <p>I am developing an application for Android.</p>
  
  <p>My application contains ten buttons, to which I have set an onclicklistener() method.
  The ten buttons contains the digits 0-9.</p>
  
  <p>Now, if I click any two or three buttons among the ten buttons, the corresponding digits must be entered into edit text and it must be shown in the edittext box.</p>
  
  <p>I am able to display the single digit if I click on any of the buttons, but if I click on another button, then the previous value disappears and the new value is shown. </p>
  
  <p>But what I want is this: no matter how many buttons I click, that no. of digits will appear in the edittext box.</p>
  
  <p>Please can anyone explain to me the code, or give me a hint so that it can be made in a simpler way.</p>