"Introduction to Java Mobile/PDA Programming" Reading notes 8--lcdaui thread time control of low-level APIs

Notes | procedures | control | design
Use thread to resolve problems that paint () and user input responses will do at the same time.

public class MyCanvas extends Canvas implements runnable{int r=0, public mycanvas () {thread t=new thread (this); T.start ();   public void Run () {while (true) {r++;   if (r>10) r=0;  Repaint ();  } public void Paint (Graphics g) {clear (g); Paintanimation (G,100,10,R);    } protected void keypressed (int keycode) {switch (getgameaction (keycode)) {case canvas.up:y=y-2;   Break ...... } }}

J2ME has removed the Stop () method (J2SE is no longer advocated), we use the identity (flag) to solve the problem of thread end Boolean conti=false;......if (Cmd.equals ("Stop")) {conti=false; Removecommand (stop); AddCommand (start); else if (cmd.equals ("start")) {Removecommand (start); AddCommand (stop); conti=true; Thread T=new thread (this); T.start ();}  ... public void run () {while (conti) {r++;  if (r>10) r=0; Repaint (); }}

Time control different machine processing speed is different, in order to maintain the game, the picture consistency, through the time control process to solve ... int rate=50 (50 millisecond =1/20 seconds screen redraw) public void run () {long s1=0; long s2=0; long diff=0;  while (Conti) {s1=systen.currenttimemillis ();  Repaint ();  Servicerepaints ();  S2=systen.currenttimemillis ();  DIFF=S2-S1;  System.out.rpintln (diff);   if (diff<rate) {try {thread.sleep (Rate-diff); }catch (Exception exc) {}} repaint (); }}