RecyclerView item height and width change dynamically Android

问题

I am new to android development and I am developing an app where the app downloads pictures from server and show them in a gridView. But some extra spaces are coming up when the app is run on a bigger screen phone. Here are some screenshots. How do I solve this ? I have the model of each item with a fixed height and width of 110dp

My image model :

<?xml version="1.0" encoding="utf-8"?>
<ImageView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="110dp"
    android:layout_height="110dp"
    app:srcCompat="@drawable/post2"
    android:id="@+id/imageView2"
    android:adjustViewBounds="true"
    android:scaleType="centerCrop"
    android:layout_margin="1.5dp" />

My Recycler View :

<android.support.v7.widget.RecyclerView
                android:id="@+id/gallerygrid"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="4dp"
                android:numColumns="auto_fit"
                android:stretchMode="columnWidth"
                android:visibility="visible"
                android:layout_gravity="center">

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

回答1:

Set height and width dynamically according to the screen size. this is the best way to get perfect result.

DisplayMetrics displaymetrics = new DisplayMetrics();
        ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        //if you need three fix imageview in width
        int devicewidth = displaymetrics.widthPixels / 3;

        //if you need 4-5-6 anything fix imageview in height
        int deviceheight = displaymetrics.heightPixels / 4;

        holder.image_view.getLayoutParams().width = devicewidth;

        //if you need same height as width you can set devicewidth in holder.image_view.getLayoutParams().height
        holder.image_view.getLayoutParams().height = deviceheight;

try this in adapter in getview hope you get better result in all device

EDIT: Or to set same height same as width you can set devicewidth in height also like below:

holder.image_view.getLayoutParams().height = devicewidth;

回答2:

for those who want to do it in the xml layout (recyclerView item) file you can use a ConstraintLayout by combining

            android:layout_width="match_parent"
            android:layout_height="wrap_content"

and the following code for having a square item

            app:layout_constraintDimensionRatio="4:4"

and don't forget to provide all the constraint that way you can set

            android:layout_width="0dp"
            android:layout_height="0dp"

hence the complete code will be as follow

<androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="1dp"
        android:layout_marginEnd="1dp"
        >

        <ImageView
            android:id="@+id/img_view"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_marginTop="1dp"
            android:layout_marginBottom="1dp"
            app:layout_constraintDimensionRatio="4:4"
            app:srcCompat="@drawable/event_placeholder"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            android:scaleType="centerCrop"
            />
</androidx.constraintlayout.widget.ConstraintLayout>

来源：https://stackoverflow.com/questions/42808433/recyclerview-item-height-and-width-change-dynamically-android

标签

android

android-recyclerview