以下圖片 code來自https://github.com/thinkSky1206。
為RecyclerView添加分隔線
主頁面layout布局很基本的。
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/md_grey_300"> //設定灰色背景
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"/>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
宣告class去繼承RecyclerView.ItemDecoration，改寫getItemOffsets方法
public class SimplePaddingDecoration extends RecyclerView.ItemDecoration {
private int dividerHeight;
public SimplePaddingDecoration(Context context) {
Resource res = context.getResources();
dividerHeight = res.getDimensionPixelSize(R.dimen.divider_height);
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.bottom = dividerHeight; //為itemView添加長度為dividerHeight的間隔(留白)
}
}
使用自定義的itemDecoration
recyclerView.addItemDecoration(new SimplePaddingDecoration(this));
結果：
這樣就完成一個簡單的帶有分隔線的view。
缺點：
分隔線的顏色是因為背景色，若我們想分隔線和背景為不同顏色，此方法不可行。
public class SimpleDividerDecoration extends RecyclerView.ItemDecoration {
private int dividerHeight; //分隔線高度
private Paint dividerPaint; //繪製分隔線的paint
public SimpleDividerDecoration(Context context) {
Resource res = context.getResources();
dividerPaint = new Paint();
dividerPaint.setColor(context.getResources().getColor(R.color.colorAccent));
dividerHeight = res.getDimensionPixelSize(R.dimen.divider_height);
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.bottom = dividerHeight;
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
/**
* childCount : 取得recycleView所擁有的itemView總數
* left : RecyclerView 的左邊界加上 paddingLeft距離 後的坐標位置
* right : RecyclerView 的右邊界減去 paddingRight 後的坐標位置
*/
int childCount = parent.getChildCount();
int left = parent.getPaddingLeft();
int right = parent.getWidth() - parent.getPaddingRight();
//
for (int i = 0; i < childCount - 1; i++) {
View view = parent.getChildAt(i);
float top = view.getBottom();
float bottom = view.getBottom() + dividerHeight;
c.drawRect(left, top, right, bottom, dividerPaint);
}
}
}
結果：
