如何在Android上将多个ImageView拖放到其他ImageView上

Question

我是 Android 的新手。目前的代码可以在单个 ImageView 上拖放多个 Image View，但我无法将它们放在多个 Image View 上。请帮忙修改我的代码或其他现有代码。

MainActivity.java

package n.f.letters;

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 MainActivity 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,image3,image4;
    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.activity_main);
        ViewGroup container = (ViewGroup) findViewById(R.id.container);
        imageDrop=(ImageView) findViewById(R.id.ImgDrop);       
        image1=(ImageView) findViewById(R.id.img1);
        image2=(ImageView) findViewById(R.id.img2);
        image3=(ImageView) findViewById(R.id.img3);
        image4=(ImageView) findViewById(R.id.img4);
        container.setOnTouchListener(new View.OnTouchListener() 
        {
            public boolean onTouch(View v, MotionEvent event) 
            {
                if(touchFlag==true)
                {
                  switch (event.getActionMasked()) 
                    {
                    case MotionEvent.ACTION_DOWN :

                         topy=imageDrop.getTop();
                         leftX=imageDrop.getLeft();
                         rightX=imageDrop.getRight();   
                         bottomY=imageDrop.getBottom();

                        //opRect.
                        break;
                    case MotionEvent.ACTION_MOVE:
                        crashX=(int) event.getX();
                        crashY=(int) event.getY();


                        int x = (int) event.getX() - offset_x;
                        int y = (int) event.getY()- offset_y;                                          

                        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);
        image3.setOnTouchListener(this);
        image4.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;
    }
}

activity_main.xml

<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_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:background="#FFF123" />

<ImageView
    android:id="@+id/img4"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:layout_marginRight="75dp"
    android:layout_marginTop="61dp"
    android:background="@drawable/ic_launcher" />

<ImageView
    android:id="@+id/img3"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:layout_alignTop="@+id/img4"
    android:layout_toRightOf="@+id/ImgDrop"
    android:background="@drawable/ic_launcher" />

<ImageView
    android:id="@+id/img2"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:layout_alignRight="@+id/ImgDrop"
    android:layout_alignTop="@+id/img3"
    android:layout_marginRight="23dp"
    android:background="@drawable/ic_launcher" />

<ImageView
    android:id="@+id/img1"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:layout_alignTop="@+id/img2"
    android:layout_marginRight="40dp"
    android:layout_toLeftOf="@+id/img2"
    android:background="@drawable/ic_launcher" />

- Nikita Fernandes

---

有没有其他的解决方案？如果有，请告诉我。我已经被这个问题困扰了很长时间。 - Nikita Fernandes

谢谢，你的问题让我找到了解决方案 :) - Yog Guru

我想知道，为什么你没有使用Android的拖放框架？ - nilo de roock

Answer 1

拖放 使用Android拖放框架，您可以允许用户使用图形化的拖放手势将数据从一个视图移动到当前布局中的另一个视图。该框架包括拖动事件类、拖动监听器和辅助方法和类。

尽管该框架主要设计用于数据移动，但您也可以将其用于其他UI操作。例如，您可以创建一个应用程序，当用户将颜色图标拖动到另一个图标上时混合颜色。然而，本主题的其余部分是以数据移动为基础来描述该框架。 查看链接

- Sonu Kumar