如何在android 2.2中实现拖放？

Question

我正在尝试开发一个Android应用程序，用户应该能够将图像从网格的一个单元格拖动到另一个单元格。为了实现这一点，我需要在Android 3.0中引入的拖放API，但我的应用程序应该在Android 2.2中运行。那么，有没有办法使用Touch事件实现这一点？如果是，那么请提供一些代码片段或简要介绍它的任何链接。

Answer 1

嗨，经过很长时间的成功，在Android 2.2中做了拖放操作

在这里，我给出了能够让你获得成功的代码。我的主要课程就在这里

 package info.tempDD;

    import android.app.Activity;
    import android.graphics.Rect;
    import android.graphics.drawable.Drawable;
    import android.os.Bundle;
    import android.view.MotionEvent;
    import android.view.View;
    import android.view.View.OnTouchListener;
    import android.view.ViewGroup;
    import android.view.ViewGroup.LayoutParams;
    import android.view.Window;
    import android.view.WindowManager;
    import android.widget.ImageView;
    import android.widget.RelativeLayout;

   public class TempDDActivity extends Activity implements OnTouchListener {
        /** Called when the activity is first created. */
        private View selected_item = null;
        private int offset_x = 0;
        private int offset_y = 0;
        Boolean touchFlag=false;
        boolean dropFlag=false;
        LayoutParams imageParams;
        ImageView imageDrop,image1,image2;
        int crashX,crashY;
        Drawable dropDrawable,selectDrawable;
        Rect dropRect,selectRect;
        int topy,leftX,rightX,bottomY;

        int dropArray[];    

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            this.requestWindowFeature(Window.FEATURE_NO_TITLE);
            this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
            setContentView(R.layout.main);
            ViewGroup container = (ViewGroup) findViewById(R.id.container);
            imageDrop=(ImageView) findViewById(R.id.ImgDrop);       
            image1=(ImageView) findViewById(R.id.img);      
            image2=(ImageView) findViewById(R.id.img2);
            container.setOnTouchListener(new View.OnTouchListener() 
            {
                public boolean onTouch(View v, MotionEvent event) 
                {
                    if(touchFlag==true)
                    {
                        System.err.println("Display If  Part ::->"+touchFlag);
                        switch (event.getActionMasked()) 
                        {
                        case MotionEvent.ACTION_DOWN :

                             topy=imageDrop.getTop();
                             leftX=imageDrop.getLeft();
                             rightX=imageDrop.getRight();   
                             bottomY=imageDrop.getBottom();
                            System.err.println("Display Top-->"+topy);      
                            System.err.println("Display Left-->"+leftX);
                            System.err.println("Display Right-->"+rightX);
                            System.err.println("Display Bottom-->"+bottomY);                


                            //opRect.
                            break;
                        case MotionEvent.ACTION_MOVE:
                            crashX=(int) event.getX();
                            crashY=(int) event.getY();
                            System.err.println("Display Here X Value-->"+crashX);
                            System.err.println("Display Here Y Value-->"+crashY);

                            int x = (int) event.getX() - offset_x;
                            int y = (int) event.getY() - offset_y;                                          
                            //int w = getWindowManager().getDefaultDisplay().getWidth() - 100;
                            //int h = getWindowManager().getDefaultDisplay().getHeight() - 100;
                            int w = getWindowManager().getDefaultDisplay().getWidth() - 50;
                            int h = getWindowManager().getDefaultDisplay().getHeight() - 10;
                            if (x > w)
                                x = w;
                            if (y > h)
                                y = h;                      
                            RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(new ViewGroup.MarginLayoutParams(  RelativeLayout.LayoutParams.WRAP_CONTENT,   RelativeLayout.LayoutParams.WRAP_CONTENT));
                            lp.setMargins(x, y, 0, 0);                  

                            //Drop Image Here                       
                            if(crashX > leftX && crashX < rightX && crashY > topy && crashY < bottomY )                     
                            {                           
                                Drawable temp=selected_item.getBackground();                            
                                imageDrop.setBackgroundDrawable(temp);
                                imageDrop.bringToFront();                           
                                dropFlag=true;
                                selected_item.setVisibility(View.INVISIBLE);
                            }
                            //Drop Image Here                       
                            selected_item.setLayoutParams(lp);
                            break;  
                        case MotionEvent.ACTION_UP:
                            //                      
                            touchFlag=false;
                            if(dropFlag==true)
                            {
                                dropFlag=false;
                            }
                            else
                            {
                                selected_item.setLayoutParams(imageParams);
                            }                       
                            break;
                        default:
                            break;
                        }
                    }else
                    {
                        System.err.println("Display Else Part ::->"+touchFlag);
                    }               
                    return true;
                }
            });

            image1.setOnTouchListener(this);
            image2.setOnTouchListener(this);
        }

        public boolean onTouch(View v, MotionEvent event) 
        {   
            switch (event.getActionMasked()) 
            {
            case MotionEvent.ACTION_DOWN:
                touchFlag=true;
                offset_x = (int) event.getX();
                offset_y = (int) event.getY();
                selected_item = v;
                imageParams=v.getLayoutParams();
                break;
            case MotionEvent.ACTION_UP:
                selected_item=null;
                touchFlag=false;
                break;
            default:
                break;
            }       
            return false;
        }
    }

之后创建一个类并像RelativeLayout一样扩展主布局

package info.tempDD;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.RelativeLayout;

public class TouchInterceptor extends RelativeLayout {
    public TouchInterceptor(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {

        return super.onInterceptTouchEvent(ev);
    }

}

主要我的Xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/container"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/ImgDrop"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_alignParentTop="true"
        android:layout_centerInParent="true"
        android:layout_marginTop="50dp"
        android:background="#FFFFFF" >
    </ImageView>

    <ImageView
        android:id="@+id/img"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_alignParentBottom="true"
        android:background="@drawable/ic_launcher" >
    </ImageView>

    <ImageView
        android:id="@+id/img2"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:background="@drawable/ic_launcher" >
    </ImageView>

</RelativeLayout>

好的，我很高兴我完成了我的工作并且也很开心因为我对我的工作感到满意，我希望这会对你有所帮助。  以及给我路的链接如下。

• rxwen-blog-stuff
• android-drag-and-drop-basic

Answer 2

DragDropManager.class

package com.example.dragdrop;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;

import android.annotation.TargetApi;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Build;
import android.view.ActionMode;
import android.view.ActionMode.Callback;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.accessibility.AccessibilityEvent;
import android.widget.ImageView;
import android.widget.PopupWindow;

public class DragDropManager
{
    private static DragDropManager instance;
    private Activity mActivity;
    private List<View> dropzones;
    private Map<View, Integer> dropzonestates;
    private Map<View, DropZoneListener> dropzonelisteners;
    private PopupWindow popoup;
    private MotionEvent firstEvent;
    private Rect rect;
    private Object item;

    public static DragDropManager getInstance()
    {
        if (instance == null) instance = new DragDropManager();
        return instance;
    }

    private DragDropManager()
    {
    }

    public void init(Activity a)
    {
        mActivity = a;
        dropzones = new ArrayList<View>();
        dropzonelisteners = new HashMap<View, DropZoneListener>();
        dropzonestates = new HashMap<View, Integer>();
        rect = new Rect();
    }

    public void addDropZone(View zone, DropZoneListener zonelistener)
    {
        dropzones.add(zone);
        dropzonelisteners.put(zone, zonelistener);
        dropzonestates.put(zone, 0);
    }

    public void clearZones()
    {
        dropzones.clear();
        dropzonelisteners.clear();
        dropzonestates.clear();
    }

    public void clearZone(View zone)
    {
        dropzones.remove(zone);
        dropzonelisteners.remove(zone);
        dropzonestates.remove(zone);
    }

    private void checkDropZones(MotionEvent event)
    {
        boolean isOver;
        HashSet<DropZoneListener> listeners = new HashSet<DropZoneListener>(dropzonelisteners.values());

        for (View zone : dropzones)
        {
            int[] location = new int[2];
            zone.getLocationInWindow(location);
            zone.getDrawingRect(rect);
            rect.offset(location[0], location[1]);
            isOver = rect.contains((int) event.getRawX(), (int) event.getRawY());

            switch (dropzonestates.get(zone))
            {
                case 0:
                    if (isOver)
                    {
                        for(DropZoneListener listener:listeners)
                        {
                            listener.OnDragZoneEntered(zone, item); 
                        }
                        dropzonestates.put(zone, 1);
                    }

                    break;
                case 1:
                    if (!isOver)
                    {
                        for(DropZoneListener listener:listeners)
                        {
                            listener.OnDragZoneLeft(zone, item);    
                        }
                        dropzonestates.put(zone, 0);
                    }
                    else if (isOver && event.getAction()==MotionEvent.ACTION_UP)
                    {
                        for(DropZoneListener listener:listeners)
                        {
                            listener.OnDropped(zone, item); 
                        }
                        dropzonestates.put(zone, 0);
                    }
                    break;
            }
        }
    }

    public void startDragging(final View dragView, Object item)
    {
        this.item = item;
        // Copy view Bitmap (Clone Object visual)
        ImageView view = new ImageView(mActivity);
        view.measure(dragView.getWidth(), dragView.getHeight());

        Bitmap returnedBitmap = Bitmap.createBitmap(dragView.getWidth(), dragView.getHeight(),Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(returnedBitmap);
        dragView.draw(canvas);

        view.setBackgroundDrawable(new BitmapDrawable(dragView.getResources(), returnedBitmap));

        // Set up Window
        popoup = new PopupWindow(view, dragView.getWidth(), dragView.getHeight());
        popoup.setWindowLayoutMode(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

        // set window at position
        int[] location = new int[2];
        dragView.getLocationInWindow(location);
        popoup.showAtLocation(mActivity.getWindow().getDecorView(), Gravity.NO_GRAVITY, location[0], location[1]);
        // Switch call Backs
        callbackDefault = mActivity.getWindow().getCallback();
        mActivity.getWindow().setCallback(callback);
    }

    private android.view.Window.Callback callbackDefault;

    private android.view.Window.Callback callback = new android.view.Window.Callback()
    {

        @Override
        public boolean dispatchGenericMotionEvent(MotionEvent event)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean dispatchKeyEvent(KeyEvent event)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean dispatchKeyShortcutEvent(KeyEvent event)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean dispatchTouchEvent(MotionEvent event)
        {
            checkDropZones(event);

            if (event.getAction() == MotionEvent.ACTION_DOWN)
            {
                // popoup.update((int)event.getRawX(), (int)event.getRawY(), -1,
                // -1);
            }

            if (event.getAction() == MotionEvent.ACTION_MOVE)
            {
                if (firstEvent == null) firstEvent = MotionEvent.obtain(event);

                // Log.v("EVENT","X:"+event.getRawX() + " _X:" + location[0] +
                // " __X:" + firstEvent.getRawX());
                // Log.v("EVENT","Y:"+event.getRawY() + " _Y:" + location[1] +
                // " __Y:" + firstEvent.getRawY());

                float pos_x = event.getRawX() + (-popoup.getWidth() / 2);
                float pos_y = event.getRawY() + (-popoup.getHeight() / 2);

                popoup.update((int) pos_x, (int) pos_y, -1, -1);

            }

            if (event.getAction() == MotionEvent.ACTION_UP)
            {
                popoup.dismiss();
                mActivity.getWindow().setCallback(callbackDefault);
            }

            return false;
        }

        @Override
        public boolean dispatchTrackballEvent(MotionEvent event)
        {
            return false;
        }

        @TargetApi(Build.VERSION_CODES.HONEYCOMB)
        @Override
        public void onActionModeFinished(ActionMode mode)
        {
            // TODO Auto-generated method stub

        }

        @TargetApi(Build.VERSION_CODES.HONEYCOMB)
        @Override
        public void onActionModeStarted(ActionMode mode)
        {
            // TODO Auto-generated method stub

        }

        @Override
        public void onAttachedToWindow()
        {
            // TODO Auto-generated method stub

        }

        @Override
        public void onContentChanged()
        {
            // TODO Auto-generated method stub

        }

        @Override
        public boolean onCreatePanelMenu(int featureId, Menu menu)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public View onCreatePanelView(int featureId)
        {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public void onDetachedFromWindow()
        {
            // TODO Auto-generated method stub

        }

        @Override
        public boolean onMenuItemSelected(int featureId, MenuItem item)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean onMenuOpened(int featureId, Menu menu)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public void onPanelClosed(int featureId, Menu menu)
        {
            // TODO Auto-generated method stub

        }

        @Override
        public boolean onPreparePanel(int featureId, View view, Menu menu)
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean onSearchRequested()
        {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public void onWindowAttributesChanged(android.view.WindowManager.LayoutParams attrs)
        {
            // TODO Auto-generated method stub

        }

        @Override
        public void onWindowFocusChanged(boolean hasFocus)
        {
            // TODO Auto-generated method stub

        }

        @TargetApi(Build.VERSION_CODES.HONEYCOMB)
        @Override
        public ActionMode onWindowStartingActionMode(Callback callback)
        {
            // TODO Auto-generated method stub
            return null;
        }

    };

    public interface DropZoneListener
    {

        void OnDragZoneEntered(View zone, Object item);

        void OnDragZoneLeft(View zone, Object item);

        void OnDropped(View zone, Object item);

    }
}

---

MainActivity.class

package com.example.dragdrop;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnLongClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.example.dragdrop.DragDropManager.DropZoneListener;

public class MainActivity extends Activity implements OnLongClickListener, OnTouchListener
{

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        DragDropManager.getInstance().init(this);

        Button b1 = (Button) findViewById(R.id.button1);
        Button b2 = (Button) findViewById(R.id.button2);
        Button b3 = (Button) findViewById(R.id.button3);

        EditText et1 = (EditText) findViewById(R.id.editText1);
        TextView tv1 = (TextView) findViewById(R.id.textView1);

        Button b4 = (Button) findViewById(R.id.button4);
        Button b5 = (Button) findViewById(R.id.button5);
        Button b6 = (Button) findViewById(R.id.button6);

        b1.setOnTouchListener(this);
        b2.setOnLongClickListener(this);
        b3.setOnTouchListener(this);

        et1.setOnTouchListener(this);
        tv1.setOnTouchListener(this);

        DragDropManager.getInstance().addDropZone(b4, dropZoneListener1);
        DragDropManager.getInstance().addDropZone(b5, dropZoneListener1);
        DragDropManager.getInstance().addDropZone(b6, dropZoneListener1);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    DropZoneListener dropZoneListener1 = new DropZoneListener()
    {

        @Override
        public void OnDropped(View zone, Object item)
        {
            Log.v("ddddd","drop time");
            switch(zone.getId())
            {
                case R.id.button4:
                    if (item instanceof String) 
                        ((Button)zone).setText("DROP ITEM OK");
                    else    
                        ((Button)zone).setText("DROP ITEM ERR");

                    break;
                case R.id.button5:
                    ((Button)zone).setText("DROP");
                    break;
                case R.id.button6:
                    if (item instanceof Integer) 
                        ((Button)zone).setText("DROP ITEM OK");
                    else    
                        ((Button)zone).setText("DROP ITEM ERR");
                    break;
            }

        }

        @Override
        public void OnDragZoneLeft(View zone, Object item)
        {

            switch(zone.getId())
            {
                case R.id.button4:
                    ((Button)zone).setText("LEFT");
                    break;
                case R.id.button5:
                    ((Button)zone).setText("LEFT");
                    break;
                case R.id.button6:
                    ((Button)zone).setText("LEFT");
                    break;
            }
        }

        @Override
        public void OnDragZoneEntered(View zone, Object item)
        {
            switch(zone.getId())
            {
                case R.id.button4:
                    if (item instanceof String) 
                        ((Button)zone).setText("ENTER ITEM OK");
                    else    
                        ((Button)zone).setText("ENTER ITEM ERR");
                    break;
                case R.id.button5:
                    ((Button)zone).setText("ENTER");
                    break;
                case R.id.button6:
                    if (item instanceof Integer) 
                        ((Button)zone).setText("ENTER ITEM OK");
                    else    
                        ((Button)zone).setText("ENTER ITEM ERR");
                    break;
            }
        }
    };

    @Override
    public boolean onLongClick(View v)
    {
        DragDropManager.getInstance().startDragging(v, 0);
        return false;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event)
    {
        DragDropManager.getInstance().startDragging(v, "String");
        return false;
    }

}

---

activity_main.xml

<RelativeLayout 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"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="14dp"
        android:text="Click" />

    <Button
        android:id="@+id/button2"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignLeft="@+id/button1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="29dp"
        android:text="Long" />

    <Button
        android:id="@+id/button3"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignLeft="@+id/button2"
        android:layout_below="@+id/button2"
        android:layout_marginTop="16dp"
        android:text="Click" />

    <Button
        android:id="@+id/button6"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_alignTop="@+id/button3"
        android:layout_marginLeft="39dp"
        android:layout_toRightOf="@+id/button3"
        android:text="Drop3" />

    <Button
        android:id="@+id/button5"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignLeft="@+id/button4"
        android:layout_centerVertical="true"
        android:text="Drop2" />

    <Button
        android:id="@+id/button4"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_above="@+id/button5"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="35dp"
        android:layout_marginRight="20dp"
        android:text="Drop1" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button3"
        android:layout_below="@+id/button3"
        android:layout_marginTop="17dp"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/button6"
        android:layout_alignParentLeft="true"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge" />

</RelativeLayout>

---

我从MobileAnarchyWidget获得了一些灵感，但我改进了一些东西。

正如你所看到的，我使用PopupWindow来创建dragEfect，即使我从可拖动对象克隆视觉部分。此外，我不必使用布局的任何部分。简单地将DragDropManager.class放到您的项目中。无需任何更改。没有其他资源。如果一个区域已满/部分覆盖另一个区域，则可以立即命中更多区域。你可以拖动任何至少是视图的东西。我在Activity窗口上切换回调，所以当你拖动其他内容时，没有其他东西可以访问事件。在这个解决方案中，你永远不会失去Draggable的焦点，当你从屏幕上拿起手指时，DragDrop将自动结束（Activity重新获得对回调的控制）。

我没有时间向您展示所有使用的组合。但正如你所看到的那样 ony one DropZoneListener。您可以使用更多，但请记住调用所有侦听器并将所有更改的拖动状态发送到每个侦听器。

例如： Dropzones D1，D2; 听众L1，L2;

如果D1或D2改变了 L1（Dx）和L2（Dx）

如果D1和D2改变了 L1（D1，D2）和L2（D1，D2）

但它很好，因为你知道它是否被丢弃在其他地方。我忘了DragItem是Object所以当删除时你必须解析对象的类型。但这也很好，因为当你使用片段时，你永远不知道可以拖动什么样的数据。

在我的解决方案中，我会检查对象类型级别。如果dragzone不支持object，那么你就不知道了。

Answer 3

view.setOnTouchListener（new View.OnTouchListener（）{

        public boolean onTouch(View v, MotionEvent me) {


            if (me.getAction() == MotionEvent.ACTION_MOVE) {


                v.setX(me.getRawX() - (v.getWidth() / 2));
                v.setY(me.getRawY() - (float)(v.getHeight()* 1.5 / 2));

            }

            return true;
        }
    }

）;

Answer 4

  

TouchEvent：TouchDown - ＆gt; LockItemOnTouchPoint

     

FollowTouchDirections - ＆gt; UpdateItemPosition

     

TouchEvent：TouchUp - ＆gt; LockItemPosition