ListView实例学习一

listview本身的功能并不多,我们既然要实现拖曳排序,自然要重写它了.下面是核心代码EditMyStockView.java
主要实现方法是:
拦截touch时间,如果点在拖曳图标上,就"吃"掉此次事件,开始执行拖曳.
否则就传给下一层,执行控件的点击操作,或者交给本身再次处理,执行listview自身的拖动操作.

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packagecom.iceman.test.listview;

 

importandroid.content.Context;

importandroid.graphics.Bitmap;

importandroid.graphics.Canvas;

importandroid.graphics.Color;

importandroid.graphics.PixelFormat;

importandroid.util.AttributeSet;

importandroid.view.Gravity;

importandroid.view.MotionEvent;

importandroid.view.View;

importandroid.view.ViewGroup;

importandroid.view.WindowManager;

importandroid.widget.AdapterView;

importandroid.widget.ImageView;

importandroid.widget.ListAdapter;

importandroid.widget.ListView;

 

importcom.iceman.test.listview.EditMyStockView.EditListAdapter;

 

publicclass DragListView extendsListView {

 

    privateImageView dragImageView;// 被拖拽的项，其实就是一个ImageView

 

    privateString[] moveitem;

 

    privateint dragPosition;// 手指按下的时候列表项在listview中的位置

 

    privateint savePosition;// 用于交换列表项用

 

    privateint movePosition;// 手指拖动的时候，当前拖动项在列表中的位置

 

    privateint dragPoint;// 在当前数据项中的位置

 

    privateint dragOffset;// 当前视图和屏幕的距离(这里只使用了y方向上)

 

    privateWindowManager windowManager;// windows窗口控制类

 

    privateWindowManager.LayoutParams windowParams;// 用于控制拖拽项的显示的参数

 

    privateViewGroup itemView;

 

    privateEditListAdapter mSelectAdapter;

 

    privateint mEventY = 0;

 

    privateString[] mReplaceString = newString[] {

            "",""

    };

 

    publicDragListView(Context context, AttributeSet attrs) {

        super(context, attrs);

    }

 

    @Override

    publicvoid setAdapter(ListAdapter adapter) {

        super.setAdapter(adapter);

        mSelectAdapter = (EditListAdapter) getAdapter();

    }

 

    // 拦截touch事件，其实就是加一层控制

    @Override

    publicboolean onInterceptTouchEvent(MotionEvent ev) {

        if(ev.getAction() == MotionEvent.ACTION_DOWN) {

            intx = (int) ev.getX();

            inty = (int) ev.getY();

            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）

            if(dragPosition == AdapterView.INVALID_POSITION) {

                returnsuper.onInterceptTouchEvent(ev);

            }

            savePosition = dragPosition;

            movePosition = dragPosition;

            moveitem = mSelectAdapter.getItem(dragPosition);

            itemView = (ViewGroup) getChildAt(dragPosition - getFirstVisiblePosition());// 获取当前点击的view

            dragPoint = y - itemView.getTop();// 点击坐标-view的上边界

            dragOffset = (int) (ev.getRawY() - y);// 整个屏幕中的y坐标-listview中的y坐标,即偏移量

            View dragger = itemView.findViewById(R.id.move_item);

            if(dragger != null&& x > dragger.getLeft() && x < dragger.getRight()) {

                itemView.setDrawingCacheEnabled(true);

                Bitmap bm = Bitmap.createBitmap(itemView.getDrawingCache());

                mSelectAdapter.remove(moveitem);

                mSelectAdapter.insert(mReplaceString, dragPosition);

                startDrag(bm, y);

                returntrue;

            }else{

                returnfalse;

            }

        }

        returnfalse;

    }

 

    /**

     * 触摸事件

     */

    @Override

    publicboolean onTouchEvent(MotionEvent ev) {

        intaction = ev.getAction();

        if(dragImageView != null&& dragPosition != INVALID_POSITION) {

            switch(action) {

                caseMotionEvent.ACTION_UP:

                    stopDrag();

                    insertLastData(movePosition);

                    mEventY = 0;

                    itemView.destroyDrawingCache();

                    break;

                caseMotionEvent.ACTION_MOVE:

                    intmoveY = (int) ev.getY();

                    mEventY = moveY;

                    onDrag(moveY, (int) ev.getRawY());

                    break;

                caseMotionEvent.ACTION_DOWN:

                    break;

            }

            returntrue;

        }else{

            returnsuper.onTouchEvent(ev);

        }

    }

 

    @Override

    protectedvoid onDraw(Canvas canvas) {

        super.onDraw(canvas);

        if(mEventY != 0) {

            if(mEventY != 0&& mEventY <= 0) {

                setSelectionFromTop(getFirstVisiblePosition(), getChildAt(0).getTop() + 3);

            }elseif (mEventY >= getHeight()) {

                setSelectionFromTop(getFirstVisiblePosition(), getChildAt(0).getTop() - 3);

            }

        }

    }

 

    /**

     * 准备拖动，初始化拖动项的图像

     *

     * @param bm

     * @param y

     */

    publicvoid startDrag(Bitmap bm, inty) {

        stopDrag();

 

        windowParams = newWindowManager.LayoutParams();

        windowParams.gravity = Gravity.TOP;

        windowParams.x = 0;

 

        windowParams.y = y - dragPoint + dragOffset;

        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 = newImageView(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

     */

    publicvoid stopDrag() {

        if(dragImageView != null) {

            windowManager.removeView(dragImageView);

            dragImageView = null;

            itemView.setBackgroundColor(Color.TRANSPARENT);

        }

    }

 

    privatevoid insertLastData(intposition) {

        String[] dragItem = mSelectAdapter.getItem(position);

        mSelectAdapter.remove(dragItem);

        mSelectAdapter.insert(moveitem, position);

    }

 

    /**

     * 拖动执行，在Move方法中执行

     */

    publicvoid onDrag(inty, intrawY) {

        if(y < 0) { // 超出上边界，设为最小值位置0

            y = 0;

        }elseif (y > getHeight()) {

            y = getHeight();

 

        }

        postInvalidate();

        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

        inttempPosition = pointToPosition(0, y);

        if(tempPosition != INVALID_POSITION) {

            movePosition = tempPosition;

            onDrop(y);

        }

 

    }

 

    publicvoid onDrop(inty) { // 根据拖动的位置在列表中放下

        if(movePosition > savePosition) {// 鼠标向下移动

            ChangeItemDown(savePosition, movePosition);

            savePosition = movePosition;

        }elseif (movePosition < savePosition) {// 鼠标向上移动

            ChangeItemUp(savePosition, movePosition);

            savePosition = movePosition;

        }

    }

 

    privatevoid ChangeItemDown(intsave, intmove) {// 向下拖动

        String[] itemStr = mSelectAdapter.getItem(move);

        mSelectAdapter.remove(mSelectAdapter.getItem(save));

        mSelectAdapter.remove(itemStr);

        mSelectAdapter.insert(itemStr, save);

        mSelectAdapter.insert(mReplaceString, move);

    }

 

    privatevoid ChangeItemUp(intsave, intmove) {// 向上拖动

        String[] itemStr = mSelectAdapter.getItem(move);

        mSelectAdapter.remove(mSelectAdapter.getItem(save));

        mSelectAdapter.remove(itemStr);

        mSelectAdapter.insert(mReplaceString, move);

        mSelectAdapter.insert(itemStr, save);

    }

}

下面是activity类:

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packagecom.iceman.test.listview;

 

importjava.util.ArrayList;

 

importandroid.app.Activity;

importandroid.content.Context;

importandroid.os.Bundle;

importandroid.view.LayoutInflater;

importandroid.view.View;

importandroid.view.View.OnClickListener;

importandroid.view.ViewGroup;

importandroid.widget.BaseAdapter;

importandroid.widget.ImageView;

importandroid.widget.TextView;

 

publicclass EditMyStockView extendsActivity{

    privateDragListView mShowAll;

 

    privateEditListAdapter mSelectAdapter;

 

    privateArrayList<String> mCodeData = newArrayList<String>();

 

    privateArrayList<String> mNameData = newArrayList<String>();

 

 

    @Override

    protectedvoid onCreate(Bundle savedInstanceState) {

        // TODO Auto-generated method stub

        super.onCreate(savedInstanceState);

        dataInit();

        setContentView(R.layout.dzh_delete_win);

        mShowAll = (DragListView) findViewById(R.id.dzh_del_win_show_all);

        System.out.println(mShowAll==null);

        mSelectAdapter = newEditListAdapter(this);

        mSelectAdapter.updateData(mCodeData, mNameData);

        mShowAll.setAdapter(mSelectAdapter);

    }

 

 

    publicvoid dataInit() {

        mCodeData.clear();

        mNameData.clear();

        for(inti=0;i<20;i++){

            mCodeData.add("股票代码"+"6000"+i);

            mNameData.add("股票名称"+i);

        }

    }

 

    classEditListAdapter extendsBaseAdapter {

        privateArrayList<String> mShowCodeData = newArrayList<String>();

 

        privateArrayList<String> mShowNameData = newArrayList<String>();

 

        privateContext mContext;

 

        privateLayoutInflater mInflater;

 

        publicEditListAdapter(Context context) {

            // TODO Auto-generated constructor stub

            this.mContext = context;

            mInflater = LayoutInflater.from(mContext);

        }

 

        publicclass ViewHolder {

            TextView code;

 

            TextView name;

 

            ImageView move;

 

            ImageView delete;

 

        }

 

        @Override

        publicint getCount() {

            // TODO Auto-generated method stub

            returnmShowCodeData.size();

        }

 

        @Override

        publicString[] getItem(intposition) {

            // TODO Auto-generated method stub

            returnnew String[] {

                    mShowCodeData.get(position), mShowNameData.get(position)

            };

        }

 

        @Override

        publiclong getItemId(intposition) {

            // TODO Auto-generated method stub

            returnposition;

        }

 

        @Override

        publicView getView(intposition, View convertView, ViewGroup parent) {

            // TODO Auto-generated method stub

            finalint pos = position;

            ViewHolder holder = null;

            if(convertView == null) {

                convertView = mInflater.inflate(R.layout.dzh_delete_win_item, null);

                holder = newViewHolder();

                holder.code = (TextView) convertView.findViewById(R.id.dzh_delete_item_code);

                holder.name = (TextView) convertView.findViewById(R.id.dzh_delete_item_name);

                holder.move = (ImageView) convertView.findViewById(R.id.move_item);

                holder.delete = (ImageView) convertView.findViewById(R.id.dzh_delete_item_delete);

                convertView.setTag(holder);

            }else{

                holder = (ViewHolder) convertView.getTag();

            }

            String itemCodeName = mShowCodeData.get(position);

            String itemSymbolName = mShowNameData.get(position);

            if(itemCodeName.equals("")) {

                holder.move.setBackgroundColor(EditMyStockView.this.getResources().getColor(R.color.touming_color));

                holder.delete.setBackgroundColor(EditMyStockView.this.getResources().getColor(R.color.touming_color));

            }else{

                holder.move.setBackgroundResource(R.drawable.edit_move);

                holder.delete.setBackgroundResource(R.drawable.win_item_delete);

            }

            if(itemCodeName != null) {

                OnClickListener itemListener = newOnClickListener() {

                    @Override

                    publicvoid onClick(View v) {

                        switch(v.getId()) {

                            caseR.id.dzh_delete_item_delete:

                                deleteItem(pos);

                                break;

                        }

                    }

                };

                holder.code.setText(itemCodeName);

                holder.name.setText(itemSymbolName);

                holder.delete.setOnClickListener(itemListener);

            }

            returnconvertView;

        }

 

        publicvoid up(intposition) {

            if(position == 0)

                return;

            String codeUpData = mShowCodeData.get(position);

            String codeDownData = mShowCodeData.get(position - 1);

            mShowCodeData.set(position, codeDownData);

            mShowCodeData.set(position - 1, codeUpData);

            String nameUpData = mShowNameData.get(position);

            String nameDownData = mShowNameData.get(position - 1);

            mShowNameData.set(position, nameDownData);

            mShowNameData.set(position - 1, nameUpData);

            this.notifyDataSetChanged();

        }

 

        publicvoid down(intposition) {

            if(position == mShowCodeData.size() - 1)

                return;

            String codeDownData = mShowCodeData.get(position);

            String codeUpData = mShowCodeData.get(position + 1);

            mShowCodeData.set(position, codeUpData);

            mShowCodeData.set(position + 1, codeDownData);

            String nameDownData = mShowNameData.get(position);

            String nameUpData = mShowNameData.get(position + 1);

            mShowNameData.set(position, nameUpData);

            mShowNameData.set(position + 1, nameDownData);

            this.notifyDataSetChanged();

        }

 

        publicvoid deleteItem(intposition) {

            if(position > mShowCodeData.size() - 1)

                return;

            mShowCodeData.remove(position);

            mShowNameData.remove(position);

            this.notifyDataSetChanged();

        }

 

        publicvoid deleteAll() {

            mShowCodeData.clear();

            mShowNameData.clear();

            this.notifyDataSetChanged();

        }

 

        publicvoid updateData(ArrayList<String> codeData, ArrayList<String> nameData) {

            mShowCodeData = codeData;

            mShowNameData = nameData;

            this.notifyDataSetChanged();

        }

 

        publicvoid remove(String[] item) {

            mShowCodeData.remove(item[0]);

            mShowNameData.remove(item[1]);

            this.notifyDataSetChanged();

        }

 

        publicvoid insert(String[] item, intindex) {

            mShowCodeData.add(index, item[0]);

            mShowNameData.add(index, item[1]);

            this.notifyDataSetChanged();

        }

    }

}

可拖曳item的listview实例.原文链接如下 ：
http://www.apkbus.com/android-70382-1-1.html