【移动应用开发技术】Android如何实现可拖拽的GridView效果长按可拖拽删除数据源

【移动应用开发技术】Android如何实现可拖拽的GridView效果长按可拖拽删除数据源

在下给大家分享一下Android如何实现可拖拽的GridView效果长按可拖拽删除数据源，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！Android可拖拽的GridView效果实现,长按可拖拽和item实时交换简单修改，完成自己想要的功能：长按，移到垃圾桶，删除数据。主要思路是：1.获取到用户长按的操作2.获取按下的图片的bitmap以及移动的时候动态刷新镜像3action_up的时候判断镜像的位置，进入是否删除逻辑自定义控件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("ernal.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;

}MainActivity.javapackage

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;

}

}UninstallListener.javapackage

com.leafact.GridView;

public

interface

UninstallListener

{

void

onUninstallListener(int

position);

}activity_main.xml<LinearLayout

xmlns:android="/apk/res/android"

xmlns:tools="/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="#fff"

android:orientation="vertical"

tools:co