View 拖动&插入
即： 支持 拖动图标 然后把之插入 2个View 之间
为了降低难度 选用了若干ImageView 放入ViewGroup : vertical LinearLayout
[代码 步骤]
1. 定义布局:main.xml ：
< ?xml version="1.0" encoding="utf-8"?> < LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/linear" > < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing1_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing2_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing3_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing3_b"/> < /LinearLayout>
2. 变量初始化
lLayout = (LinearLayout)findViewById(R.id.linear);
3. 定义OnTouchListener 用于监听所有动作 并注册LinearLayour的所有View 实现为：
touchListener = new OnTouchListener(){[email protected] public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub int action = event.getAction(); int x = (int) event.getRawX(); int y = (int) event.getRawY(); switch(action){ //鼠标按下 拖拉动作开始 case MotionEvent.ACTION_DOWN: point1 = v.getTop(); startX = (int)event.getX(); startY = y - v.getTop(); break; //鼠标移动 拖拉动作进行中 case MotionEvent.ACTION_MOVE: v.layout(x - startX, y - startY, x + v.getWidth() - startX, y - startY + v.getHeight()); v.bringToFront(); v.postInvalidate(); break; //鼠标释放 拖拉动作结束 case MotionEvent.ACTION_UP: point2 = v.getTop(); //计算插入位置 位于哪两个相邻View之间 int dest = getLocation(v); //remove ori view, and then add view here lLayout.removeView(v); lLayout.addView(v, dest); break; } return false; } }; //to listener all ImageView for(int i=0;i< p> ImageView iv = (ImageView)lLayout.getChildAt(i); if(iv !=null){ iv.setOnTouchListener(touchListener); } else { //error, view is null! } }4. getLocation(View) 用于： 根据目标View 判断待插入的位置 即：哪2个相邻ImageView 之间 实现为：
public int getLocation(View v){ for(int i=0;i< p>ImageView iv = (ImageView)lLayout.getChildAt(i); ImageView iv2 = (ImageView)lLayout.getChildAt(i+1); if(iv.getTop()< v.getTop() && iv2.getTop() > v.getTop()){ //refer delta of point1 & point2 if(point1 < point2){//drag to bottom return i+1; } else {//drag to up return i+1; } } } //otherwise return last location return lLayout.getChildCount()-1; }