How to make span count and icon size automatic

问题

I am using recycler view with card view to show icons in my application. I am not able to figure out how to resize the app icons and increase/decrease the span count automatically depending on the screen size. Here is what I am doing to display it and the spen count is fixed to 3.

    RecyclerView mrv = (RecyclerView) findViewById(R.id.recyclerview_id);
    RecyclerViewAdapter myAdapter = new RecyclerViewAdapter(this, lsStore);
    mrv.setLayoutManager(new GridLayoutManager(this, 3));
    mrv.setAdapter(myAdapter);

The XMLs are below

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/cardview_id"
android:clickable="true"
android:foreground="?selectableItemBackground"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:cardview="http://schemas.android.com/apk/res-auto"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginTop="15dp"
android:layout_marginVertical="20dp"
cardview:cardCornerRadius="6dp">


<android.support.v7.widget.LinearLayoutCompat
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <ImageView
        android:id="@+id/store_image_id"
        android:layout_width="wrap_content"
        android:layout_height="110dp"
        android:scaleType="centerCrop"
        android:background="#2D2D2D"/>

    <TextView
        android:id="@+id/store_name_id"
        android:textColor="#2d2d2d"
        android:textSize="13sp"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/StoreTitle"/>


</android.support.v7.widget.LinearLayoutCompat>

The app is doing nice in a screen size of around 5"5' to 6" screen but on screens smaller/bigger that, the icons looks messy. Can someone please guide me how to achieve this?

回答1:

You can calculate number of columns. Define a static function to calculate the number of columns as:

public class Utility {
    public static int calculateNoOfColumns(Context context) {
        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        float dpWidth = displayMetrics.widthPixels / displayMetrics.density;
        int noOfColumns = (int) (dpWidth / 180);
        // Where 180 is the width of your grid item. You can change it as per your convention.
        return noOfColumns;
    }
}

And then, when using the GridLayoutManager in the activity or fragment you can do like this:

int mNoOfColumns = Utility.calculateNoOfColumns(getApplicationContext());

// Some code...

mGridLayoutManager = new GridLayoutManager(this, mNoOfColumns);
mRecyclerView.setLayoutManager(mGridLayoutManager);

// Some code...

I hope, this helps you.

来源：https://stackoverflow.com/questions/53207401/how-to-make-span-count-and-icon-size-automatic