具有缩放选项

Question

我想准备StaggeredGridView。我准备好以下代码：

MainActivity：

public class MainActivity extends AppCompatActivity {

    private StaggeredGridLayoutManager gaggeredGridLayoutManager;

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

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.myrecyclerview);
        recyclerView.setHasFixedSize(true);

        gaggeredGridLayoutManager = new StaggeredGridLayoutManager(2, 1);
        recyclerView.setLayoutManager(gaggeredGridLayoutManager);

        List<ItemData> gaggeredList = getListItemData();

        MyStaggeredGridViewAdapter rcAdapter = new MyStaggeredGridViewAdapter(MainActivity.this, gaggeredList);
        recyclerView.setAdapter(rcAdapter);
    }

    private List<ItemData> getListItemData() {

        List<ItemData> listViewItems = new ArrayList<ItemData>();
        listViewItems.add(new ItemData(1, R.drawable.scene_1, "Scene 1", "Description", 11, 30));
        listViewItems.add(new ItemData(2, R.drawable.scene_2, "Scene 2", "Description", 11, 30));
        listViewItems.add(new ItemData(3, R.drawable.scene_3, "Scene 3", "Description", 11, 30));
        listViewItems.add(new ItemData(4, R.drawable.scene_4, "Scene 4", "Description", 11, 30));
        listViewItems.add(new ItemData(5, R.drawable.scene_5, "Scene 5", "Description", 11, 30));
        listViewItems.add(new ItemData(6, R.drawable.scene_6, "Scene 6", "Description", 11, 30));
        listViewItems.add(new ItemData(7, R.drawable.scene_7, "Scene 7", "Description", 11, 30));
        listViewItems.add(new ItemData(8, R.drawable.scene_8, "Scene 8", "Description", 11, 30));
        listViewItems.add(new ItemData(9, R.drawable.scene_9, "Scene 9", "Description", 11, 30));
        return listViewItems;
    }
}

activity_main.xml中

<android.support.v7.widget.RecyclerView
    android:id="@+id/myrecyclerview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

item_xml

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/ivItemImage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:scaleType="fitCenter" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="@dimen/activity_horizontal_margin">

        <TextView
            android:id="@+id/tvItemPrimaryText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:text="Primary Text"
            android:textAppearance="@style/TextAppearance.AppCompat.Medium" />

        <TextView
            android:id="@+id/tvItemSecondaryText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/tvItemPrimaryText"
            android:text="Secondary Text"
            android:textAppearance="@style/TextAppearance.AppCompat.Small" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingTop="6dp"
            android:layout_below="@+id/tvItemSecondaryText"
            android:gravity="center_vertical">

            <ImageView
                android:id="@+id/ivItemFavourites"
                android:layout_width="16dp"
                android:layout_height="16dp"
                android:layout_marginRight="8dp"
                android:src="@drawable/ic_favorite_24dp" />

            <TextView
                android:id="@+id/tvItemLikes"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="8dp"
                android:text="23" />

            <ImageView
                android:id="@+id/ivItemComments"
                android:layout_width="16dp"
                android:layout_height="16dp"
                android:layout_marginRight="8dp"
                android:src="@drawable/ic_comment_24dp" />

            <TextView
                android:id="@+id/tvItemComments"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="8dp"
                android:text="23" />

        </LinearLayout>


    </RelativeLayout>
</LinearLayout>

MyStaggeredGridViewAdapter

public class MyStaggeredGridViewAdapter extends RecyclerView.Adapter<GridViewItemHolder> {

private List<ItemData> itemList;
private Context context;

public MyStaggeredGridViewAdapter(Context context, List<ItemData> itemList) {
    this.itemList = itemList;
    this.context = context;
}

@Override
public GridViewItemHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_xml, null);
    GridViewItemHolder rcv = new GridViewItemHolder(layoutView);
    return rcv;
}

@Override
public void onBindViewHolder(GridViewItemHolder holder, int position) {
    ItemData itemData = itemList.get(position);
    holder.getmImageView().setImageResource(itemData.getImageUrl());

    holder.getmImageView().setImageBitmap(scaleToActualAspectRatio(holder.getmImageView().getWidth(), itemData.getImageUrl()));

    holder.getmTextViewPrimaryText().setText(itemData.getPrimaryText());
    holder.getmTextViewSecondaryText().setText(itemData.getSecondaryText());
    holder.getmTextViewLikes().setText(String.valueOf(itemData.getLikes()));
    holder.getmTextViewComments().setText(String.valueOf(itemData.getComments()));
}

@Override
public int getItemCount() {
    return this.itemList.size();
}


public Bitmap scaleToActualAspectRatio(int width, int resId) {


}
}

我正在寻找一些逻辑。 要求：我会根据imageView的宽度设置两列，并设置图像的高度。图像的纵横比不应受到干扰。

那么，为什么要用我的scaleToActualAspectRatio方法编写什么逻辑？

简而言之，我想要一个从我这里获取width和resourceId并相应地缩放Bitmap而不会丢失高宽比的方法。我已经在使用像android:adjustViewBounds="true"和android:scaleType="fitCenter"这样的ImageView属性 ellipse(mouseX, mouseY, radius, radius);但希望有效地加载大图像和大量图像。

感谢。