android开发分享RecyclerView自定义分割线

RecyclerView自定义分割线

import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.view.View;  import androidx.core.content.ContextCompat; import androidx.core.view.ViewCompat; import androidx.recyclerview.widget.RecyclerView;   public class RecyclerViewDivider extends RecyclerView.ItemDecoration {      private Paint mPaint;     private Drawable mDivider;     private int mDividerHeight;     private int mOrientation;     /**      * 系统默认的分割线      */     private static final int[] ATTRS = new int[]{android.R.attr.listDivider};      /**      * 设置默认的分割线      *      * @param orientation 指代分割线的方向      */     public RecyclerViewDivider(Context context, int orientation) {         this.mDividerHeight = 2;         if (orientation != 1 && orientation != 0) {             throw new IllegalArgumentException("请输入正确的参数！");         } else {             this.mOrientation = orientation;             TypedArray a = context.obtainStyledAttributes(ATTRS);             this.mDivider = a.getDrawable(0);             a.recycle();         }     }      /**      * 设置图片资源为分割线      */     public RecyclerViewDivider(Context context, int orientation, int drawableId) {         this(context, orientation);         this.mDivider = ContextCompat.getDrawable(context, drawableId);         this.mDividerHeight = this.mDivider.getIntrinsicHeight();     }      /**      * 设置线条颜色和高度给分割线      */     public RecyclerViewDivider(Context context, int orientation, int dividerHeight, int dividerColor) {         this(context, orientation);         this.mDividerHeight = dividerHeight;         this.mPaint = new Paint(1);         this.mPaint.setColor(dividerColor);         this.mPaint.setStyle(Paint.Style.FILL);     }      @Override     public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {         super.getItemOffsets(outRect, view, parent, state);         outRect.set(0, 0, 0, this.mDividerHeight);     }      @Override     public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {         super.onDraw(c, parent, state);         if (this.mOrientation == 1) {             this.drawVertical(c, parent);         } else {             this.drawHorizontal(c, parent);         }     }      private void drawHorizontal(Canvas canvas, RecyclerView parent) {         canvas.save();         final int left;         final int right;         // 判断RecyclerView是否要裁剪padding值         if (parent.getClipToPadding()) {             // 需要裁剪那么就进行裁剪             left = parent.getPaddingLeft();             right = parent.getWidth() - parent.getPaddingRight();             // 裁剪rv可视区域,  限制视图在该区域内是可见的，很重要的，这里             canvas.clipRect(left, parent.getPaddingTop(), right, parent.getHeight() - parent.getPaddingBottom());         } else {             //  不裁剪则宽贼为rv的宽             left = 0;             right = parent.getWidth();         }          int childSize = parent.getChildCount();         for (int i = 0; i < childSize; ++i) {             View child = parent.getChildAt(i);             // 获得item的信息包             RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();             // 分割线顶部 = item的底部 + item到底部的距离 + 动画偏移             int top = child.getBottom() + layoutParams.bottomMargin + Math.round(ViewCompat.getTranslationY(child));             // 分割线底部 =  分割线底部 + 高度             int bottom = top + this.mDividerHeight;             if (this.mDivider != null) {                 this.mDivider.setBounds(left, top, right, bottom);                 this.mDivider.draw(canvas);             }              if (this.mPaint != null) {                 canvas.drawRect((float) left, (float) top, (float) right, (float) bottom, this.mPaint);             }         }         canvas.restore();     }      private void drawVertical(Canvas canvas, RecyclerView parent) {         canvas.save();         final int top;         final int bottom;         if (parent.getClipToPadding()) {             top = parent.getPaddingTop();             bottom = parent.getHeight() - parent.getPaddingBottom();             canvas.clipRect(parent.getPaddingLeft(), top, parent.getWidth() - parent.getPaddingRight(), bottom);         } else {             top = 0;             bottom = parent.getHeight();         }          int childSize = parent.getChildCount();          for (int i = 0; i < childSize; ++i) {             View child = parent.getChildAt(i);             RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();             int left = child.getRight() + layoutParams.rightMargin + Math.round(ViewCompat.getTranslationX(child));             int right = left + this.mDividerHeight;             if (this.mDivider != null) {                 this.mDivider.setBounds(left, top, right, bottom);                 this.mDivider.draw(canvas);             }              if (this.mPaint != null) {                 canvas.drawRect((float) left, (float) top, (float) right, (float) bottom, this.mPaint);             }         }         canvas.restore();     }  }