RecyclerView 的條目之間沒有分割線东抹，需要我們自己去定義添加
第一步，自定義一個類繼承于 RecyclerView.ItemDecoration
public class MyItemDecoration extends RecyclerView.ItemDecoration {
private Context mContext;
private Drawable mDivider;
private int mOrientation;
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
//我們通過獲取系統(tǒng)屬性中的listDivider來添加本缠，在系統(tǒng)中的AppTheme中設置
public static final int[] ATRRS = new int[]{
android.R.attr.listDivider
};
/**
* 默認分割線
* @param context
* @param orientation
*/
public MyItemDecoration(Context context, int orientation) {
this.mContext = context;
final TypedArray ta = context.obtainStyledAttributes(ATRRS);
this.mDivider = ta.getDrawable(0);
ta.recycle();
setOrientation(orientation);
}
//設置屏幕的方向
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == HORIZONTAL_LIST) {
drawVerticalLine(c, parent, state);
} else {
drawHorizontalLine(c, parent, state);
}
}
//畫橫線, 這里的parent其實是顯示在屏幕顯示的這部分
public void drawHorizontalLine(Canvas c, RecyclerView parent, RecyclerView.State state) {
int left = parent.getPaddingLeft();
int right = parent.getWidth() - parent.getPaddingRight();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
//獲得child的布局信息
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
//Log.d("wnw", left + " " + top + " "+right+" "+bottom+" "+i);
}
}
//畫豎線
public void drawVerticalLine(Canvas c, RecyclerView parent, RecyclerView.State state) {
int top = parent.getPaddingTop();
int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
//獲得child的布局信息
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
//由于Divider也有長寬高斥扛，每一個Item需要向下或者向右偏移
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == HORIZONTAL_LIST) {
//畫橫線，就是往下偏移一個分割線的高度
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
//畫豎線丹锹，就是往右偏移一個分割線的寬度
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
}
}
}
第二步稀颁，在代碼中設置
//設置分割線
mFragmentRecyclerview.addItemDecoration(new MyItemDecoration(getActivity(),LinearLayoutManager.VERTICAL));
第三步，修改分割線的顏色和高度楣黍，需要在 AppTheme 中設置
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<!--android:listDivider 是為了設置 recyclerview 的分割線的顏色高度等信息-->
<item name="android:listDivider">@drawable/shape_line</item>
- shape_line.xml 是一個自定義的 shape 匾灶，可以設置 shape 來改變顏色和高度
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<!--控制 recyclerView 分割線的顏色和高度-->
<solid android:color="@color/dark_gray"></solid>
<size android:height="10dp"></size>
</shape>
