参考: http://www.cnblogs.com/qianxudetianxia/archive/2011/06/12/2068761.html
主要看上面那个链接 作者写的非常详细 在此谢过了
可拖拽的listview:
package com.fengjian.test; import android.content.Context; import android.graphics.Bitmap; import android.graphics.PixelFormat; import android.util.AttributeSet; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.view.WindowManager; import android.widget.AdapterView; import android.widget.ImageView; import android.widget.ListView; import android.widget.Toast; import com.fengjian.test.DragListActivity.DragListAdapter; /** * http://www.cnblogs.com/qianxudetianxia/archive/2011/06/12/2068761.html * @author li * */ public class DragListView extends ListView { private ImageView dragImageView;//被拖拽的项,其实就是一个ImageView private int dragSrcPosition;//手指拖动项原始在列表中的位置 private int dragPosition;//手指拖动的时候,当前拖动项在列表中的位置 private int dragPoint;//在当前数据项中的位置 private int dragOffset;//当前视图和屏幕的距离(这里只使用了y方向上) private WindowManager windowManager;//windows窗口控制类 private WindowManager.LayoutParams windowParams;//用于控制拖拽项的显示的参数 private int scaledTouchSlop;//判断滑动的一个距离 private int upScrollBounce;//拖动的时候,开始向上滚动的边界 private int downScrollBounce;//拖动的时候,开始向下滚动的边界 public DragListView(Context context, AttributeSet attrs) { super(context, attrs); scaledTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop(); } //拦截touch事件,其实就是加一层控制 @Override public boolean onInterceptTouchEvent(MotionEvent ev) { if(ev.getAction()==MotionEvent.ACTION_DOWN){ int x = (int)ev.getX(); int y = (int)ev.getY(); System.out.println("x: "+ x +" y: "+ y +" RawX: "+ev.getRawX()+" RawY: "+ev.getRawY()); dragSrcPosition = dragPosition = pointToPosition(x, y);//判断当前xy值 是否在item上 如果在 返回改item的position 否则 返回 INVALID_POSITION(-1) System.out.println("super.onInterceptTouchEvent(ev): "+super.onInterceptTouchEvent(ev)); if(dragPosition==AdapterView.INVALID_POSITION){ return super.onInterceptTouchEvent(ev); } System.out.println("dragPosition: "+dragSrcPosition +" getFirstVisiblePosition(): "+getFirstVisiblePosition()); //getChildAt(int position)参数 为当前屏幕里面显示的item 从0开始 并不是adapter里面的位置 如果当前屏幕显示的微list从 5--8 的数据 则 //getChildAt(0) 为在list中position为5的那个item //getFirstVisiblePosition()返回第一个显示在界面的view在adapter的位置position,可能是0,也可能是4 ViewGroup itemView = (ViewGroup) getChildAt(dragPosition-getFirstVisiblePosition()); System.out.println("itemView.getTop(): " + itemView.getTop()); dragPoint = y - itemView.getTop(); // lipeng add //dragPoint = itemView.getTop(); dragOffset = (int) (ev.getRawY() - y); View dragger = itemView.findViewById(R.id.drag_list_item_image); if(dragger!=null&&x>dragger.getLeft()-20){ // upScrollBounce = Math.min(y-scaledTouchSlop, getHeight()/3); downScrollBounce = Math.max(y+scaledTouchSlop, getHeight()*2/3); itemView.setDrawingCacheEnabled(true); Bitmap bm = Bitmap.createBitmap(itemView.getDrawingCache()); startDrag(bm, y); } return false; } return super.onInterceptTouchEvent(ev); } /** * 触摸事件 */ @Override public boolean onTouchEvent(MotionEvent ev) { if(dragImageView!=null&&dragPosition!=INVALID_POSITION){ int action = ev.getAction(); switch(action){ case MotionEvent.ACTION_UP: int upY = (int)ev.getY(); stopDrag(); onDrop(upY); break; case MotionEvent.ACTION_MOVE: int moveY = (int)ev.getY(); //onDrag(moveY); // lipeng add onDrag(moveY,(int)ev.getRawY()); break; default:break; } return true; } //也决定了选中的效果 return super.onTouchEvent(ev); } /** * 准备拖动,初始化拖动项的图像 * @param bm * @param y */ public void startDrag(Bitmap bm ,int y){ stopDrag(); windowParams = new WindowManager.LayoutParams(); windowParams.gravity = Gravity.TOP; windowParams.x = 0; windowParams.y = y - dragPoint + dragOffset; //windowParams.y = dragPoint + 50;// lipeng add windowParams.width = WindowManager.LayoutParams.WRAP_CONTENT; windowParams.height = WindowManager.LayoutParams.WRAP_CONTENT; windowParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN; windowParams.format = PixelFormat.TRANSLUCENT; windowParams.windowAnimations = 0; ImageView imageView = new ImageView(getContext()); imageView.setImageBitmap(bm); windowManager = (WindowManager)getContext().getSystemService("window"); windowManager.addView(imageView, windowParams); dragImageView = imageView; } /** * 停止拖动,去除拖动项的头像 */ public void stopDrag(){ if(dragImageView!=null){ windowManager.removeView(dragImageView); dragImageView = null; } } /** * 拖动执行,在Move方法中执行 * @param y */ public void onDrag(int y){ if(dragImageView!=null){ windowParams.alpha = 0.8f; windowParams.y = y - dragPoint + dragOffset; windowManager.updateViewLayout(dragImageView, windowParams); } //为了避免滑动到分割线的时候,返回-1的问题 int tempPosition = pointToPosition(0, y); if(tempPosition!=INVALID_POSITION){ dragPosition = tempPosition; } //滚动 int scrollHeight = 0; if(y<upScrollBounce){ scrollHeight = 8;//定义向上滚动8个像素,如果可以向上滚动的话 }else if(y>downScrollBounce){ scrollHeight = -8;//定义向下滚动8个像素,,如果可以向上滚动的话 } if(scrollHeight!=0){ //真正滚动的方法setSelectionFromTop() setSelectionFromTop(dragPosition, getChildAt(dragPosition-getFirstVisiblePosition()).getTop()+scrollHeight); } } // lipeng add { /** * 拖动执行,在Move方法中执行 * @param y */ public void onDrag(int y,int rawY){ if(dragImageView!=null){ windowParams.alpha = 0.8f; //windowParams.y = y - dragPoint + dragOffset; windowParams.y = rawY-dragPoint; windowManager.updateViewLayout(dragImageView, windowParams); } //为了避免滑动到分割线的时候,返回-1的问题 int tempPosition = pointToPosition(0, y); if(tempPosition!=INVALID_POSITION){ dragPosition = tempPosition; } //滚动 int scrollHeight = 0; if(y<upScrollBounce){ scrollHeight = 8;//定义向上滚动8个像素,如果可以向上滚动的话 }else if(y>downScrollBounce){ scrollHeight = -8;//定义向下滚动8个像素,,如果可以向上滚动的话 } if(scrollHeight!=0){ //真正滚动的方法setSelectionFromTop() setSelectionFromTop(dragPosition, getChildAt(dragPosition-getFirstVisiblePosition()).getTop()+scrollHeight); } } // lipeng add } /** * 拖动放下的时候 * @param y */ public void onDrop(int y){ //为了避免滑动到分割线的时候,返回-1的问题 int tempPosition = pointToPosition(0, y); if(tempPosition!=INVALID_POSITION){ dragPosition = tempPosition; } //超出边界处理 if(y<getChildAt(1).getTop()){ //超出上边界 dragPosition = 1; }else if(y>getChildAt(getChildCount()-1).getBottom()){ //超出下边界 dragPosition = getAdapter().getCount()-1; } //数据交换 if(dragPosition>0&&dragPosition<getAdapter().getCount()){ DragListAdapter adapter = (DragListAdapter)getAdapter(); String dragItem = adapter.getItem(dragSrcPosition); adapter.remove(dragItem); adapter.insert(dragItem, dragPosition); Toast.makeText(getContext(), adapter.getList().toString(), Toast.LENGTH_SHORT).show(); } } }
main类:
package com.fengjian.test; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.TextView; public class DragListActivity extends Activity { private static List<String> list = null; private DragListAdapter adapter = null; public static List<String> groupKey= new ArrayList<String>(); private List<String> navList = new ArrayList<String>(); private List<String> moreList = new ArrayList<String>(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.drag_list_activity); initData(); DragListView dragListView = (DragListView)findViewById(R.id.drag_list); adapter = new DragListAdapter(this, list); dragListView.setAdapter(adapter); } public void initData(){ //数据结果 list = new ArrayList<String>(); //groupKey存放的是分组标签 groupKey.add("A组"); groupKey.add("B组"); for(int i=0; i<5; i++){ navList.add("A选项"+i); } list.add("A组"); list.addAll(navList); for(int i=0; i<8; i++){ moreList.add("B选项"+i); } list.add("B组"); list.addAll(moreList); } public static class DragListAdapter extends ArrayAdapter<String>{ public DragListAdapter(Context context, List<String> objects) { super(context, 0, objects); } public List<String> getList(){ return list; } @Override public boolean isEnabled(int position) { if(groupKey.contains(getItem(position))){ //如果是分组标签,返回false,不能选中,不能点击 return false; } return super.isEnabled(position); } @Override public View getView(int position, View convertView, ViewGroup parent) { View view = convertView; if(groupKey.contains(getItem(position))){ //如果是分组标签,就加载分组标签的布局文件,两个布局文件显示效果不同 view = LayoutInflater.from(getContext()).inflate(R.layout.drag_list_item_tag, null); }else{ //如果是正常数据项标签,就加在正常数据项的布局文件 view = LayoutInflater.from(getContext()).inflate(R.layout.drag_list_item, null); } TextView textView = (TextView)view.findViewById(R.id.drag_list_item_text); textView.setText(getItem(position)); return view; } } }
drag_list_activity.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" > <com.fengjian.test.DragListView android:id="@+id/drag_list" android:layout_width="fill_parent" android:layout_height="fill_parent" android:cacheColorHint="#00000000"/> </LinearLayout>
drag_list_item_tag.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#555555" android:padding="5dip" android:paddingLeft="10dip"> <TextView android:id="@+id/drag_list_item_text" android:layout_width="wrap_content" android:layout_height="20dip" android:textColor="#ffffff" android:gravity="center_vertical"/> </LinearLayout>
drag_list_item.xml
<?xml version="1.0" encoding="utf-8"?> <!-- 一定要使用相对布局 --> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/drag_list_item_text" android:layout_width="wrap_content" android:layout_height="@dimen/drag_item_normal_height" android:paddingLeft="5dip" android:layout_alignParentLeft="true" android:layout_centerVertical="true" android:gravity="center_vertical"/> <ImageView android:id="@+id/drag_list_item_image" android:src="@drawable/list_icon" android:layout_alignParentRight="true" android:layout_centerVertical="true" android:layout_width="wrap_content" android:layout_height="@dimen/drag_item_normal_height"/> </RelativeLayout>
全部代码 就是上面这些了 截张图吧。。
注意几个问题吧 :
1、pointToPosition(x, y);
判断当前xy值 是否在item上 如果在 返回改item的position 否则 返回 INVALID_POSITION(-1)
2、getChildAt(int position)
参数 为当前屏幕里面显示的item 从0开始 并不是adapter里面的位置 如果当前屏幕显示的微list从 5--8 的数据 则getChildAt(0) 为在list中position为5的那个item
3、getFirstVisiblePosition()
返回第一个显示在界面的view在adapter的位置position,可能是0,也可能是4
4、setSelectionFromTop(position,y)
第一个参数 是需要选中的item的位置,第二个是y轴上的坐标