Question

我正在尝试使用ArrayLists将OnTouchListener设置为多个ImageViews，但我的应用程序一直在压缩。这是我的代码：

MainActivity：

public class MainActivity extends AppCompatActivity {

private DragAndDrop dragAndDrop;
private InstantiateImages   instantiateImages;

private ArrayList<ImageView> faces = new ArrayList<ImageView>();

private int    i;


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

    dragAndDrop =   new DragAndDrop();
    InstantiateImages   instantiateImages   =   new InstantiateImages(this);

    //Add   elements    to  ArrayLists:
    instantiateImages.Add();

    //Get   elements into ArrayLists:
    faces   =   instantiateImages.getFaces();

    for (i   =   0;  i< faces.size();    i++) {

        faces.get(i).setOnTouchListener(new View.OnTouchListener() {
            @Override
                public boolean onTouch(View v, MotionEvent event) {

                    //Follow the touch on the ImageView and move the 
                    //ImageView accordingly:
                    dragAndDrop.action(v, event, faces.get(i));

                    return true;
                }
            });
    }

}
}

InstantiateImages类：

public class InstantiateImages {

this.activity   =   activity;

private ArrayList<ImageView> faces = new ArrayList<ImageView>();

//Faces declarations:
private ImageView FacesNoFace;

InstantiateEmojis() {


   //Faces instantiations:
   FacesNoFace = (ImageView)this.activity.findViewById(R.id.faces_no_face);

}

public void Add() {
    //Add   faces   to ArrayList    faces:
    faces.add(FacesNoFace);
}


//Getters:
//Get   Faces:
public ArrayList<ImageView> getFaces() {
    return faces;
}
}

布局XML：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="myproject.myproject.MainActivity"
tools:layout_editor_absoluteY="81dp"
tools:layout_editor_absoluteX="0dp"
tools:background="#ffffff">

<ImageView
    android:id="@+id/faces_no_face"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="16dp"
    android:contentDescription=""
    app:srcCompat="@drawable/faces_no_face"
    tools:ignore="ContentDescription"
    tools:layout_editor_absoluteX="16dp"
    tools:layout_editor_absoluteY="16dp" />

</android.support.constraint.ConstraintLayout>

DragAndDrop类是一个只有一个方法跟随ImageView拖放（OnTouchListener的内部/内部）的方法，之后我尝试将ImageView放在我创建的ArrayList“faces”中。 “InstantiateImages”类I仅在一个ImageView（我现在添加到ArrayList的那个）上对OnTouchListener进行了维护，并且它完全正常工作（我可以在应用程序屏幕上拖放ImageView）。现在应用程序在我运行它之后就崩溃了，它说：“MyProject一直停止关闭应用程序”或“MyProject已停止重新打开应用程序”。

欢迎任何帮助!!

Answer 1

我认为你过分复杂了。我认为这会做你想做的事情。

public class MainActivity extends AppCompatActivity {

    private DragAndDrop dragAndDrop;
    private final ArrayList<ImageView> faces = new ArrayList<>();

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

        dragAndDrop = new DragAndDrop();
        faces.add((ImageView) findViewById(R.id.faces_no_face));
        for (ImageView face : faces) {
            face.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    //Follow the touch on the ImageView and move the
                    //ImageView accordingly:
                    dragAndDrop.action(v, event, (ImageView) v);
                    return false;
                }
            });
        }
    }
}

如果您计划使用可变数量的ImageView来收听点击次数，则可能需要查看RecyclerView和列表。

尝试使用ArrayLists

1 个答案: