RecyclerView分隔条

野性酷女 2023-01-16 13:27 123阅读 0赞

因为没能找到直接的控件，给RecyclerView添加item间隔，及定义分隔条颜色，所以自定义RecyclerView分隔条，方便自定义分隔条颜色，item间隔，

package com.custom.views;
    
    import android.content.Context;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Paint;
    import android.graphics.Rect;
    import android.graphics.drawable.ColorDrawable;
    import android.graphics.drawable.Drawable;
    import android.view.View;
    
    import androidx.annotation.NonNull;
    import androidx.recyclerview.widget.LinearLayoutManager;
    import androidx.recyclerview.widget.RecyclerView;
    
    public class RecyclerViewDivider extends RecyclerView.ItemDecoration{
        private final Context mContext;
        private final int mOrientation;
    //item默认间隔宽度
        private static final int DEFAULT_INTERVAL = 24;
        private static final int DEFAULT_DIVIDER_COLOR = Color.GRAY;
    //分隔条宽度
        private final int mDividerPixel = 2;
        private final int mInterval;
        private final int mDividerColor;
        private final Paint mPaint;
        private final Drawable mDivider;
    
        public RecyclerViewDivider(Context context, int orientation) {
            this(context, orientation, DEFAULT_INTERVAL, DEFAULT_DIVIDER_COLOR);
        }
    
        public RecyclerViewDivider(Context context, int orientation, int interval) {
            this(context, orientation, interval, DEFAULT_DIVIDER_COLOR);
        }
    
        public RecyclerViewDivider(Context context, int orientation, int interval, int color) {
            if (orientation != LinearLayoutManager.HORIZONTAL && orientation != LinearLayoutManager.VERTICAL) {
                throw new IllegalArgumentException("orientation invalid.");
            }
            mContext = context;
            mOrientation = orientation;
            mInterval = interval;
            mDividerColor = color;
            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mPaint.setColor(mDividerColor);
            mPaint.setStyle(Paint.Style.FILL);
            mDivider = new ColorDrawable(Color.GRAY);
        }
    
        @Override
        public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
            super.getItemOffsets(outRect, view, parent, state);
            if (mOrientation == LinearLayoutManager.HORIZONTAL) {
                outRect.set(0, 0, mDividerPixel + DEFAULT_INTERVAL, 0);
            } else if (mOrientation == LinearLayoutManager.VERTICAL) {
                outRect.set(0, 0, 0, mDividerPixel + DEFAULT_INTERVAL);
            }
        }
    
        @Override
        public void onDraw(@NonNull Canvas canvas, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
            super.onDraw(canvas, parent, state);
            if (mOrientation == LinearLayoutManager.HORIZONTAL) {
                drawVertical(canvas, parent);
            } else {
                drawHorizontal(canvas, parent);
            }
        }
    
        private void drawHorizontal(Canvas canvas, RecyclerView recyclerView) {
            final int left = recyclerView.getPaddingLeft();
            final int right = recyclerView.getMeasuredWidth() - recyclerView.getPaddingLeft();
            final int childSize = recyclerView.getChildCount();
    
            for (int i = 0; i < childSize - 1; i++) {
                final View child = recyclerView.getChildAt(i);
                RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
    //调整分隔条在间隔宽度中间
                final int top = child.getBottom() + layoutParams.bottomMargin + DEFAULT_INTERVAL / 2;
                final int bottom = top + mDividerPixel;
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
                canvas.drawRect(left, top, right, bottom ,mPaint);
            }
        }
    
        private void drawVertical(Canvas canvas, RecyclerView recyclerView) {
            final int top = recyclerView.getPaddingTop();
            final int bottom = recyclerView.getMeasuredHeight() - recyclerView.getPaddingBottom();
            final int childSize = recyclerView.getChildCount();
            for (int i = 0; i < childSize - 1; i++) {
                final View child = recyclerView.getChildAt(i);
                RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
    //调整分隔条在间隔宽度中间
                final int left = child.getRight() + layoutParams.rightMargin + DEFAULT_INTERVAL / 2;
                final int right = left + mDividerPixel;
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }