1.在手机离开屏幕时,记录view对象距离屏幕left和top的距离,将数据存入到sp存储器中   2.在activity加载的时候获取存在sp存储器中的值,确定view对象的位置               public class DragViewActivity extends Activity {       private static final String TAG = "DragViewActivity";       private ImageView iv_dragview;       private WindowManager  wm;       private SharedPreferences sp;       private TextView  tv_dragview;
      @Override       protected void onCreate(Bundle savedInstanceState) {              super.onCreate(savedInstanceState);             setContentView(R.layout. activity_dragview);                           sp=getSharedPreferences( "config", MODE_PRIVATE);              wm=(WindowManager) getSystemService( WINDOW_SERVICE);              iv_dragview = (ImageView) findViewById(R.id. iv_dragview);             tv_dragview =(TextView) findViewById(R.id.tv_dragview);                           //当activity加载时确定Toast的位置              int left= sp.getInt( "left", 0);              int top= sp.getInt( "top", 0);             Log. i(TAG, "left:" +left);             Log. i(TAG, "top:" +top);             LayoutParams  params=(LayoutParams) iv_dragview.getLayoutParams();  //获取布局参数             params. leftMargin=left;             params. topMargin=top;              iv_dragview.setLayoutParams(params);  //设置view的布局                                        //给imageview 设置触摸事件              iv_dragview.setOnTouchListener( new OnTouchListener() {                    int startX=0;  //离屏幕左边距离                    int startY=0;                                       //当触摸时                    @Override                    public boolean onTouch(View v, MotionEvent event) {
                         switch (event.getAction()) {                          case MotionEvent. ACTION_DOWN:   //触摸到屏幕时                                startX = ( int) event.getRawX();                                startY = ( int) event.getRawY();                                break;
                         case MotionEvent. ACTION_MOVE:            //滑动时                                int newX = ( int) event.getRawX();                                int newY = ( int) event.getRawY();                                                               int dx = newX - startX;   //变化的距离                                int dy = newY - startY;                                                               int l = iv_dragview.getLeft()+dx;   //获取view对象移动后的位置                                int r = iv_dragview.getRight()+dx;                                int t = iv_dragview.getTop()+dy;                                int b = iv_dragview.getBottom()+dy;                                                                                                                             //判断view对象是都超出屏幕                                if(l<0||t<0||r> wm.getDefaultDisplay(). getWidth()||b> wm.getDefaultDisplay(). getHeight()-40){                                      break;                               }                                                                                              iv_dragview.layout(l, t, r, b);   //定位view对象位置                                                               startX = ( int) event.getRawX();   //重新获取开始位置                                startY = ( int) event.getRawY();                                                                                              int tv_height = tv_dragview.getBottom()- tv_dragview.getTop();                                //归属地提示TextView位置变化效果                                if (t > wm.getDefaultDisplay(). getHeight() / 2) {                                      // imageview 在下方, 设置textview 在上方
                                     tv_dragview.layout( tv_dragview.getLeft(), 0,                                                  tv_dragview.getRight(), tv_height);                               } else {                                      // imageview 在上方, 设置textview 在下方                                      tv_dragview.layout( tv_dragview.getLeft(), wm                                                 .getDefaultDisplay(). getHeight()                                                 - 40                                                 - tv_height, tv_dragview.getRight(), wm                                                 .getDefaultDisplay(). getHeight() - 40);
                              }                                                                                             
                               break;                          case MotionEvent. ACTION_UP:    //离开屏幕时
                               //将view对象距离屏幕左边的距离和距离屏幕上边的距离记录到 sp存储器中                                int left= iv_dragview.getLeft();                                int top= iv_dragview.getTop();                               Editor edit = sp.edit();                               edit.putInt( "left", left);                               edit.putInt( "top", top);                               edit.commit();                                                               break;                         }
                         return true;                   }             });       } }