主布局从“约束”更改为“相对”后，ListView中的ImageView不显示

Question

正如标题所述。我在主活动布局内有一个ListView。一开始它是一个ConstraintLayout，但我决定将其设置为RelativeLayout，之后，row_item内的ImageView消失了，我无法放回去，我尝试了很多答案，但没有一个可以帮助我。

这里是ListAdapter代码：

public class ListAdapter extends ArrayAdapter<Product> {
private int resourceLayout;
private Context mContext;
private List<Product> items;
private AlertDialog.Builder alert;
EditText edittext;

public ListAdapter(Context context, int resource, List<Product> items) {
    super(context, resource, items);
    this.items = items;
    this.resourceLayout = resource;
    this.mContext = context;
}



@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    alert = new AlertDialog.Builder(mContext);
    View v = convertView;
    if (v == null) {
        LayoutInflater vi;
        vi = LayoutInflater.from(mContext);
        v = vi.inflate(resourceLayout, null);
    }

    final Product p = getItem(position);
    ImageView deleteImage = (ImageView) v.findViewById(R.id.delete_image);
    deleteImage.setVisibility(View.VISIBLE);

    v.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            edittext = new EditText(mContext);
            edittext.setPaddingRelative(5,10,10,5);
            edittext.setHint("New Quantity");
            Log.d("DATABASE", " "+ position);
            new AlertDialog.Builder(mContext)
                    .setTitle("Are you sure?")
                    .setView(edittext)
                    .setMessage("Do you want to change the quantity of product " + p.getName())
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            String editedValue = edittext.getText().toString();
                            if (TextUtils.isEmpty(edittext.getText())){
                                Toast.makeText(mContext, "You need to specify a quantity", LENGTH_SHORT).show();
                            } else {
                                if (Integer.parseInt(editedValue) == 0 && Integer.parseInt(editedValue) > 100){
                                    Toast.makeText(mContext, "Quantity should be greater than 0 and less than 100", LENGTH_SHORT).show();
                                }else {
                                    p.setQuantity(Integer.parseInt(editedValue));  /// Ceva nu merge bine aici, schimba valoarea desi e 0
                                    notifyDataSetChanged();
                                }
                            }

                        }
                    })
                    .setNegativeButton("No", null)
                    .show();
        }
    });

    deleteImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new AlertDialog.Builder(mContext)
                    .setIcon(R.drawable.del_button)
                    .setTitle("Are you sure?")
                    .setMessage("Do you want to delete the product " + p.getName() + " from you shopping cart ?")
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            items.remove(position);
                            notifyDataSetChanged();
                        }
                    })
                    .setNegativeButton("No", null)
                    .show();
        }
    });




    if (p != null) {
        TextView tt1 = (TextView) v.findViewById(R.id.product_name);
        TextView tt2 = (TextView) v.findViewById(R.id.product_quantity);
        TextView tt3 = (TextView) v.findViewById(R.id.product_price);

        if (tt1 != null) {
            tt1.setText(p.getName());
        }

        if (tt2 != null) {
            tt2.setText(String.valueOf(p.getQuantity()));
        }

        if (tt3 != null) {
            tt3.setText(String.valueOf(p.getPrice()*p.getQuantity()));
        }
    }

    return v;
}

这是我的row_item布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:andorid="http://schemas.android.com/tools"
android:orientation="vertical"
android:padding="10dp">

<TextView
    android:id="@+id/product_name"
    android:textSize="25dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:text="Product Name"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/black" />


<TextView
    android:id="@+id/product_quantity"
    android:textSize="20dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/product_name"
    android:text="Quantity:"
    android:textColor="@android:color/black" />

<TextView
    android:id="@+id/product_price"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toEndOf="@id/product_name"
    android:layout_marginLeft="45dp"
    android:layout_centerInParent="true"
    android:src="@android:drawable/ic_dialog_info"
    android:text="Price"
    android:textSize="26dp" />

<ImageView
    android:id="@+id/delete_image"
    android:layout_width="42dp"
    android:layout_height="42dp"
    android:layout_alignParentEnd="true"
    android:layout_centerVertical="true"
    android:layout_marginEnd="25dp"
    android:clickable="true"
    android:focusable="true"
    andorid:src="@drawable/del_button" />

   </RelativeLayout>

这是主要布局：

<RelativeLayout 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"
android:background="#00ff00"
android:padding="15dp">

<Button
    android:id="@+id/btn_scan"
    android:layout_width="105dp"
    android:layout_height="67dp"
    android:layout_alignParentRight="true"
    android:layout_marginRight="30dp"
    android:text="SCAN"
    android:textAlignment="center"
    android:textColor="@color/colorPrimary"
    android:textSize="26dp"
    />

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="570dp"
    android:layout_marginStart="1dp"
    android:layout_marginTop="1dp"
    android:layout_marginEnd="1dp"
    android:layout_marginBottom="1dp"
    android:layout_below="@id/btn_scan" />

</RelativeLayout>

正如我说的，在将主布局从“约束”更改为“相对”之前，一切都很好。不确定是什么问题，ImageView也具有onClick方法，该方法在显示AlertDialog后删除了单击的行。哪个工作正常。不知道是什么问题，我搜寻了答案，但没有一个帮助我。另外，这是我的照片文件夹：

Answer 1

[最有可能，问题出在android:src属性中，因为它不支持只能通过app:srcCompat加载的矢量可绘制对象>

因此，请将android:src替换为app:srcCompat；因此，您的列表项布局中的ImageView为：

<ImageView
    android:id="@+id/delete_image"
    android:layout_width="42dp"
    android:layout_height="42dp"
    android:layout_alignParentEnd="true"
    android:layout_centerVertical="true"
    android:layout_marginEnd="25dp"
    android:clickable="true"
    android:focusable="true"
    app:srcCompat="@drawable/del_button" />
并且在这种情况下，它可能会发出警告，要求您在android {...}下将以下代码段添加到gradle文件中，模块级别
android {  
   defaultConfig {  
     vectorDrawables.useSupportLibrary = true  
    }  
}