course2 tank move and stop

src/com/demo/tank/coruse2/MainV2.java

@@ -1,10 +1,11 @@
 package com.demo.tank.coruse2;
 
-import com.demo.tank.coruse1.TankFrame;
-
 public class MainV2 {
-    public static void main(String[] args){
+    public static void main(String[] args) throws InterruptedException {
         TankFrame tf = new TankFrame();
+        while (true){
+            Thread.sleep(50);
             tf.repaint();
         }
+    }
 }

src/com/demo/tank/coruse2/Tank.java

@@ -1,11 +1,11 @@
 package com.demo.tank.coruse2;
 
 import java.awt.*;
-
 public class Tank {
     private int x,y;
     private Direction dir;
     private static final int SPEED = 10;
+    private boolean moving;
 
 
     public Tank(int x, int y, Direction dir) {
@@ -16,6 +16,12 @@ public class Tank {
 
     public void paint(Graphics g) {
         g.fillRect(x, y,50,50);
+        move();
+    }
+
+    public void move(){
+        //如果没有移动 return
+        if(!moving) return;
         switch (dir){
             case UP: y -= SPEED;
                 break;
@@ -53,4 +59,12 @@ public class Tank {
     public void setDir(Direction dir) {
         this.dir = dir;
     }
+
+    public boolean isMoving() {
+        return moving;
+    }
+
+    public void setMoving(boolean moving) {
+        this.moving = moving;
+    }
 }

src/com/demo/tank/coruse2/TankFrame.java

@@ -77,10 +77,15 @@ public class TankFrame extends Frame {
         }
 
         public void setTankDirection(){
+            if(!bL && !bR && !bU && !bD){
+                tank.setMoving(false);
+            }else{
+                tank.setMoving(true);
                 if(bL) tank.setDir(Direction.LEFT);
                 if(bR) tank.setDir(Direction.RIGHT);
                 if(bU) tank.setDir(Direction.UP);
                 if(bD) tank.setDir(Direction.DOWN);
             }
         }
+    }
 }