RecyclerView 添加分割线
1默认分割线
image.png
//默认分割线 水平分割线
recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
//默认分割线 竖直分割线
recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL));
2自定义分割线样式
image.png
dv = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL);
dh = new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL);
dv.setDrawable(getResources().getDrawable(R.drawable.divideritemdecoration_v));
dh.setDrawable(getResources().getDrawable(R.drawable.divideritemdecoration_h));
recyclerView.addItemDecoration(dv);
recyclerView.addItemDecoration(dh);
divideritemdecoration_v
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size android:height="5dp"/>
<gradient android:startColor="@android:color/holo_red_dark" android:angle="45"
android:centerColor="@color/colorPrimaryDark"
android:endColor="@android:color/holo_orange_dark"/>
</shape>
divideritemdecoration_h
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size android:width="5dp"/>
<gradient android:startColor="@android:color/holo_green_light"
android:angle="90"
android:centerColor="@color/colorPrimaryDark"
android:endColor="@android:color/holo_blue_dark"/>
</shape>
2自定义分割线样式 去除底部右边分割线
继承 RecyclerView.ItemDecoration
重写方法
- onDraw
- setDrawable
- getItemOffsets
public void setDrawable(@NonNull Drawable drawable) {
if (drawable == null) {
throw new IllegalArgumentException("Drawable cannot be null.");
} else {
this.mDivider = drawable;
}
}
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (parent.getLayoutManager() != null && this.mDivider != null) {
if (this.mOrientation == 1) {
this.drawVertical(c, parent); //绘制分割线要忽略最后一行
} else {
this.drawHorizontal(c, parent);//绘制分割线要忽略最后一列
}
}
}
// itemview的偏移就在此
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (this.mDivider == null) {
outRect.set(0, 0, 0, 0);
} else {
if (this.mOrientation == 1) {
//最后一列不偏移
outRect.set(0, 0, 0,parent.getAdapter().getItemCount()-parent.getChildAdapterPosition(view)<=parent.getAdapter().getItemCount()%spancount?0:this.mDivider.getIntrinsicHeight());
} else {
//最后一行不偏移
outRect.set(0, 0, parent.getChildAdapterPosition(view)%spancount!=(spancount-1)?this.mDivider.getIntrinsicWidth():0, 0);
}
}
}
问题
我们的自定义分割线宽度过大导致 界面绘制时最后列右边留白，最后行底部留白
解决问题
// t top l left r right b bottom
//偏移距离
//vindex 行
//hspancount 总行
//hindex 列
//spancount 总列
private int t(int vindex, int hspancount) {
return vindex*mDivider_V.getIntrinsicHeight()/hspancount;
}
private int b(int vindex, int hspancount) {
return (hspancount-1-vindex)*mDivider_V.getIntrinsicHeight()/hspancount;
}
private int l(int hindex) {
return mDivider_H.getIntrinsicWidth()*hindex/spancount;
}
private int r(int hindex) {
return (spancount-1-hindex)*mDivider_H.getIntrinsicWidth()/spancount;
}
image.png
