Android实现可拖拽的GridView效果长按可拖拽删除数据源

package com.leafact.GridView; 
import android.app.Activity; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.PixelFormat; 
import android.graphics.Rect; 
import android.os.Handler; 
import android.os.Vibrator; 
import android.util.AttributeSet; 
import android.view.Gravity; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.WindowManager; 
import android.widget.AdapterView; 
import android.widget.GridView; 
import android.widget.ImageView; 
import android.widget.Toast; 
/** 
* 长按能选中item的，丢入垃圾箱的gridView 
* 
* @author leafact 
* 
*/ 
public class MoveGridView extends GridView { 
private WindowManager mWindowManager; 
/** 
* item镜像的布局参数 
*/ 
private WindowManager.LayoutParams mWindowLayoutParams; 
/** 
* 震动器 
*/ 
private Vibrator mVibrator; 
// 震动的时间，默认为100ms 
private long vibratorMs = 100; 
// 设置长按时间为1秒 
private long responseMS = 1000; 
private static boolean isMove = false; 
// 按下去的x,y 
private int mDownX = 0; 
private int mDownY = 0; 
// 移动的时候的x,y 
private int mMoveX = 0; 
private int mMoveY = 0; 
// 抬起的x,y 
private int mUpX = 0; 
private int mUpY = 0; 
private int mPoint2ItemTop; 
private int mPoint2ItemLeft; 
private int mOffset2Top; 
private int mOffset2Left; 
/** 
* 状态栏的高度 
*/ 
private int mStatusHeight; 
public MoveGridView(Context context, AttributeSet attrs) { 
super(context, attrs); 
mVibrator = (Vibrator) context 
.getSystemService(Context.VIBRATOR_SERVICE); 
mWindowManager = (WindowManager) context 
.getSystemService(Context.WINDOW_SERVICE); 
mStatusHeight = getStatusHeight(context); // 获取状态栏的高度 
} 
// 要移动的item的位置,默认为INVALID_POSITION=-1 
private int mMovePosition = INVALID_POSITION; 
/** 
* 刚开始拖拽的item对应的View 
*/ 
private View mStartMoveItemView = null; 
private ImageView mMoveImageView = null; 
private Bitmap mMoveBitmap; 
private Handler mHandler = new Handler(); 
// 判断是否能开始移动元素 
private Runnable mLongClickRunnable = new Runnable() { 
@Override 
public void run() { 
isMove = true; 
mVibrator.vibrate(vibratorMs); 
// 根据我们按下的点显示item镜像 
createDragImage(mMoveBitmap, mDownX, mDownY); 
} 
}; 
@Override 
public boolean onTouchEvent(MotionEvent ev) { 
switch (ev.getAction()) { 
case MotionEvent.ACTION_DOWN: 
mDownX = (int) ev.getX(); 
mDownY = (int) ev.getY(); 
System.out.println("ACTION_DOWN"); 
// 根据按下的X,Y坐标获取所点击item的position 
mMovePosition = pointToPosition(mDownX, mDownY); 
// 如果选中的为非法的位置。则不处理消息 
if (mMovePosition == AdapterView.INVALID_POSITION) { 
break; 
} 
mHandler.postDelayed(mLongClickRunnable, responseMS); 
mStartMoveItemView = getChildAt(mMovePosition 
- getFirstVisiblePosition()); 
mPoint2ItemTop = mDownY - mStartMoveItemView.getTop(); 
mPoint2ItemLeft = mDownX - mStartMoveItemView.getLeft(); 
mOffset2Top = (int) (ev.getRawY() - mDownY); 
mOffset2Left = (int) (ev.getRawX() - mDownX); 
// 开启mMoveItemView绘图缓存 
mStartMoveItemView.setDrawingCacheEnabled(true); 
// 获取mMoveItemView在缓存中的Bitmap对象 
mMoveBitmap = Bitmap.createBitmap(mStartMoveItemView 
.getDrawingCache()); 
// 这一步很关键，释放绘图缓存，避免出现重复的镜像 
mStartMoveItemView.destroyDrawingCache(); 
break; 
case MotionEvent.ACTION_MOVE: 
mMoveX = (int) ev.getX(); 
mMoveY = (int) ev.getY(); 
// 如果我们在按下的item上面移动，只要不超过item的边界我们就不移除mRunnable 
// 依然能监听到longClick 
if (!isTouchInItem(mStartMoveItemView, mMoveX, mMoveY)) { 
mHandler.removeCallbacks(mLongClickRunnable); 
} 
// //禁止Gridview侧边进行滑动,移动的时候不许发生侧滑事件 
if (isMove) { 
onDragItem(mMoveX, mMoveY); 
return true; 
} 
break; 
case MotionEvent.ACTION_UP: 
mUpX = (int) ev.getX(); 
mUpY = (int) ev.getY(); 
mHandler.removeCallbacks(mLongClickRunnable); 
if(isMove){ 
deleteIfNeed(); 
} 
removeDragImage(); 
isMove = false; 
break; 
default: 
break; 
} 
return super.onTouchEvent(ev); 
} 
/** 
* 判断是否要删除，满足条件删除 
*/ 
private void deleteIfNeed() { 
int y = mUpY - mPoint2ItemTop + mOffset2Top 
- mStatusHeight; 
if(y<50){ 
if(mUninstallListener!=null) 
mUninstallListener.onUninstallListener(mMovePosition); 
} 
} 
/** 
* 是否点击在GridView的item上面 
* 
* @param itemView 
* @param x 
* @param y 
* @return 
*/ 
private boolean isTouchInItem(View dragView, int x, int y) { 
if (dragView == null) { 
return false; 
} 
int leftOffset = dragView.getLeft(); 
int topOffset = dragView.getTop(); 
if (x < leftOffset || x   leftOffset + dragView.getWidth()) { 
return false; 
} 
if (y < topOffset || y   topOffset + dragView.getHeight()) { 
return false; 
} 
return true; 
} 
/** 
* 创建拖动的镜像 
* 
* @param bitmap 
* @param downX 
*      按下的点相对父控件的X坐标 
* @param downY 
*      按下的点相对父控件的X坐标 
*/ 
private void createDragImage(Bitmap bitmap, int downX, int downY) { 
mWindowLayoutParams = new WindowManager.LayoutParams(); 
mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // 图片之外的其他地方透明 
mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT; 
mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left; 
mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top 
- mStatusHeight; 
mWindowLayoutParams.alpha = 0.55f; // 透明度 
mWindowLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT; 
mWindowLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT; 
mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE 
| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE; 
mMoveImageView = new ImageView(getContext()); 
mMoveImageView.setImageBitmap(bitmap); 
mWindowManager.addView(mMoveImageView, mWindowLayoutParams); 
} 
/** 
* 从界面上面移动拖动镜像 
*/ 
private void removeDragImage() { 
if (mMoveImageView != null) { 
mWindowManager.removeView(mMoveImageView); 
mMoveImageView = null; 
} 
} 
/** 
* 拖动item，在里面实现了item镜像的位置更新，item的相互交换以及GridView的自行滚动 
* 
* @param x 
* @param y 
*/ 
private void onDragItem(int moveX, int moveY) { 
mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left; 
mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top 
- mStatusHeight; 
mWindowManager.updateViewLayout(mMoveImageView, mWindowLayoutParams); // 更新镜像的位置 
} 
/** 
* 获取状态栏的高度 
* 
* @param context 
* @return 
*/ 
private static int getStatusHeight(Context context) { 
int statusHeight = 0; 
Rect localRect = new Rect(); 
((Activity) context).getWindow().getDecorView() 
.getWindowVisibleDisplayFrame(localRect); 
statusHeight = localRect.top; 
if (0 == statusHeight) { 
Class<?  localClass; 
try { 
localClass = Class.forName("com.android.internal.R$dimen"); 
Object localObject = localClass.newInstance(); 
int i5 = Integer.parseInt(localClass 
.getField("status_bar_height").get(localObject) 
.toString()); 
statusHeight = context.getResources().getDimensionPixelSize(i5); 
} catch (Exception e) { 
e.printStackTrace(); 
} 
} 
return statusHeight; 
} 
/** 
* 设置响应拖拽的毫秒数，默认是1000毫秒 
* 
* @param responseMS 
*/ 
public void setResponseMS(long responseMS) { 
this.responseMS = responseMS; 
} 
/** 
* 设置震动时间的毫秒数，默认是1000毫秒 
* 
* @param responseMS 
*/ 
public void setVibrator(long vibratorMs) { 
this.vibratorMs = vibratorMs; 
} 
public void setOnUninstallListener(UninstallListener l){ 
mUninstallListener=l; 
}; 
private UninstallListener mUninstallListener; 
} 

package com.example.gridviewmovedemo; 
import java.util.ArrayList; 
import java.util.HashMap; 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemLongClickListener; 
import android.widget.SimpleAdapter; 
import com.leafact.GridView.MoveGridView; 
import com.leafact.GridView.UninstallListener; 
public class MainActivity extends Activity { 
private MoveGridView mMoveGridView; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
mMoveGridView = (MoveGridView) findViewById(R.id.gridview); 
final ArrayList<HashMap<String, Object   lstImageItem = new ArrayList<HashMap<String, Object  (); 
for (int i = 0; i < 10; i++) { 
HashMap<String, Object  map = new HashMap<String, Object (); 
map.put("ItemText", "NO." + String.valueOf(i));// 按序号做ItemText 
lstImageItem.add(map); 
} 
final SimpleAdapter saImageItems = new SimpleAdapter(this, 
lstImageItem,// 数据来源 
R.layout.gridview_item, 
// 动态数组与ImageItem对应的子项 
new String[] { "ItemText" }, 
// ImageItem的XML文件里面的一个ImageView,两个TextView ID 
new int[] { R.id.ItemText }); 
// 添加并且显示 
mMoveGridView.setAdapter(saImageItems); 
//监听到卸载删除数据 
mMoveGridView.setOnUninstallListener(new UninstallListener() { 
@Override 
public void onUninstallListener(int position) { 
lstImageItem.remove(position); 
saImageItems.notifyDataSetChanged(); 
} 
}); 
} 
@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
getMenuInflater().inflate(R.menu.main, menu); 
return true; 
} 
} 

package com.leafact.GridView; 
public interface UninstallListener { 
void onUninstallListener(int position); 
} 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="#fff" 
android:orientation="vertical" 
tools:context=".MainActivity"   
<RelativeLayout 
android:layout_width="fill_parent" 
android:layout_height="100dip" 
android:background="#ccc"   
<TextView 
android:layout_width="wrap_content" 
android:layout_height="fill_parent" 
android:layout_centerHorizontal="true" 
android:gravity="center" 
android:text="卸载" 
android:textColor="#fff" 
android:textSize="28sp" /  
</RelativeLayout  
<com.leafact.GridView.MoveGridView 
android:id="@+id/gridview" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:horizontalSpacing="5dip" 
android:numColumns="3" 
android:verticalSpacing="5dip" /  
</LinearLayout  

<?xml version="1.0" encoding="utf-8"?  
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
android:background="#2248DD"   
<TextView 
android:id="@+id/ItemText" 
android:layout_width="wrap_content" 
android:layout_height="100dip" 
android:layout_centerHorizontal="true" 
android:gravity="center"   
</TextView  
</RelativeLayout