我正在尝试开发一款安卓应用程序，用户应该能够将图片从一个网格单元拖到另一个网格单元。为了实现这个功能，我需要使用在Android 3.0中引入的拖放API，但是我的应用程序应该在Android 2.2上运行。那么，有没有办法使用触摸事件来实现这个功能？如果是，那么请提供给我一些代码片段或任何描述它的链接。
如何在Android 2.2中实现拖放功能？
3
- Chandra Sekhar
2
以下链接将帮助您解决问题.... http://techdroid.kbeanie.com/2010/04/simple-drag-n-drop-on-android.html - himanshu
可能是在Android 2.2中拖放视图的重复问题。 - Leo supports Monica Cellio
4个回答
15
很久以后，我终于成功地在Android 2.2上实现了拖放功能。
这里是我的代码，可以帮助你实现成功。我的主类在此处。
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;
}
}
创建一个类并将其扩展为您的主布局，例如RelativeLayout
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);
}
}
同时，这是我的主要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，现在我完成了我的工作并感到非常满意，希望这能对您有所帮助。下面是提供给我的链接：
- Zala Janaksinh
2
Zala，实际上我从http://blahti.wordpress.com/2011/10/03/drag-drop-for-android-gridview/找到了我的解决方案。因此，我没有测试过你的代码。 - Chandra Sekhar
Zala，请不要在我的博客上发布任何与该网站相关的评论。你可以在这里发表评论，我会从这里回复你。如果你对我的博客主题有任何问题，那么你可以在那里发表评论。 - Chandra Sekhar
2
view.setOnTouchListener(new View.OnTouchListener() {
意思是设置一个触摸监听器，当用户在视图上进行触摸操作时，就会调用相应的方法。 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;
}
}
);
- Thilina Anuradh
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获得了一些启示，但我改进了一些东西。
正如您所看到的，我使用PopupWindow创建了拖动效果，甚至克隆了可拖动对象的可视部分。另外，我不需要使用任何布局的一部分。只需将DragDropManager.class放入您的项目中即可。无需更改。没有额外的资源。如果一个区域完全/部分覆盖另一个区域，则可以同时击中更多区域。您可以拖动任何至少是视图的内容。我在Activity窗口上切换回调，因此当您拖动某些内容时，其他内容无法访问事件。在这个解决方案中，您永远不会失去对可拖动对象的关注，并且当您从屏幕上抬起手指时，DragDrop将自动结束（Activity重新获得控制回调）。
我没有时间向您展示所有使用组合。但是，正如您所看到的，只有一个DropZoneListener。您可以使用更多，但请记住，所有侦听器都会被调用，并且所有更改的拖动状态都会被发送到每个侦听器。
例如： Dropzones D1、D2; Listener L1、L2;
如果D1或D2更改 L1（Dx）和L2（Dx）
如果D1和D2更改 L1（D1、D2）和L2（D1、D2）
但这很好，因为您知道它是否被放置在其他地方。我忘记了DragItem是对象，因此当其被放下时，您必须解析对象的类型。但这也很好，因为当您使用片段时，永远不知道可以拖动什么类型的数据。
在我的解决方案中，我会检查对象类型级别。如果对象不受拖放区支持，那么您将知道。
- Mertuarez
2
1我尝试了你的示例，但在第一次拖放后就卡住了，你有任何修复bug的方法吗？ - user1234813
哎呀，我不行。这是很久以前的事了。它确实可以在2.2 Froyo上运行。但似乎在更新的版本上不行了。想法是从Activity onTouch视图中捕获Window回调DispatchMouseEvent，并将对象位图缓冲区复制到PopupWindow中，其中x、y由mousemove更改。 - Mertuarez
-3
TouchEvent:TouchDown -> LockItemOnTouchPoint
FollowTouchDirections -> UpdateItemPosition
TouchEvent:TouchUp -> LockItemPosition
触摸事件：按下 -> 锁定触点上的项目 跟随触摸方向 -> 更新项目位置 触摸事件：抬起 -> 锁定项目位置
触摸事件：按下 -> 锁定触点上的项目 跟随触摸方向 -> 更新项目位置 触摸事件：抬起 -> 锁定项目位置
- Matthias Bruns
5
你能否简要解释一下？或者你能分享一篇解释这个的链接吗？ - Chandra Sekhar
这只是解决这个问题的一般方法。请按照@himanshu给出的链接进行操作。 - Matthias Bruns
你能分享一段代码片段，解释如何在触摸点上锁定物品以及如何跟随触摸方向吗？ - Chandra Sekhar
3我见过的最傲慢的回答...如果你努力解释一下你写的内容，那就好了。 - azfar
同意@azfar的观点，无法相信Chandra Sekhar甚至将其标记为正确答案。 - Leo supports Monica Cellio
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