Monitor textarea input text changes, let textarea height self-growth

Originally textarea only a row high, with the increase in the number of input words, the default growth, usually used in mobile product input

Use Oninput better than onkeyup for mobile phones

<id= "Txtcontent"  class= "j_comment_in comment-input"  rows  = "1"  oninput= "Resizetextarea (' txtcontent ')"  style= "Overflow-y: hidden; " placeholder = "I also say ..." ></ textarea >

//min. heightvarMinrows = 1; //maximum height, scroll bar appears overvarMaxRows = 6; functionResizetextarea (ID) {vart =document.getElementById (ID); if(T.scrolltop = = 0) t.scrolltop=1;  while(T.scrolltop = = 0){         if(T.rows >minrows) T.rows--; Else              Break; T.scrolltop= 1; if(T.rows <maxRows) T.style.overflowy= "hidden"; if(T.scrolltop > 0) {t.rows++;  Break; }     }      while(T.scrolltop > 0){             if(T.rows <maxRows) {T.rows++; if(T.scrolltop = = 0) t.scrolltop=1; }         Else{t.style.overflowy= "Auto";  Break; }     } } 

Monitor textarea input text changes, let textarea height self-growth