android - 我如何将多个 ImageView 拖放到其他 ImageView 上 android

Question

我是 Android 新手。目前的代码可以将多个 ImageView 拖放到单个 ImageView 上，但我无法将它们拖放到多个 ImageView 上。请帮助我如何修改我的代码或任何其他现有代码。

主 Activity .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" />

Answer 1

拖放使用 Android 拖放框架，您可以允许您的用户使用图形拖放手势将数据从一个 View 移动到当前布局中的另一个 View 。该框架包括拖动事件类、拖动监听器以及辅助方法和类。

虽然该框架主要是为数据移动而设计的，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，当用户将一个颜色图标拖到另一个图标上时混合颜色。然而，本主题的其余部分从数据移动的角度描述了框架。 link see