Android View 上下左右四种间距的设置方法

RecyclerView控件大家肯定不陌生，已经应用有一段时间了，最近在项目中写一个GridLayout样式的RecyclerView时需要设置，item之间左右的间距，下面是我总结的一个设置间距的方法分享给大家。

下面是没间距的情况

想要设置item之间的间距需要自己创建一个继承自RecyclerView.ItemDecoration的类

public class RecyclerViewSpacesItemDecoration extends RecyclerView.ItemDecoration {

   private HashMap<String, Integer> mSpaceValueMap;

   public static final String TOP_DECORATION = "top_decoration";
   public static final String BOTTOM_DECORATION = "bottom_decoration";
   public static final String LEFT_DECORATION = "left_decoration";
   public static final String RIGHT_DECORATION = "right_decoration";
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   public RecyclerViewSpacesItemDecoration(HashMap<String, Integer> mSpaceValueMap) {
       this.mSpaceValueMap = mSpaceValueMap;
   }
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   @Override
   public void getItemOffsets(Rect outRect, View view,
                               RecyclerView parent, RecyclerView.State state) {
       if (mSpaceValueMap.get(TOP_DECORATION) != null)
           outRect.top = mSpaceValueMap.get(TOP_DECORATION);
       if (mSpaceValueMap.get(LEFT_DECORATION) != null)

           outRect.left = mSpaceValueMap.get(LEFT_DECORATION);
       if (mSpaceValueMap.get(RIGHT_DECORATION) != null)
           outRect.right = mSpaceValueMap.get(RIGHT_DECORATION);
       if (mSpaceValueMap.get(BOTTOM_DECORATION) != null)

           outRect.bottom = mSpaceValueMap.get(BOTTOM_DECORATION);

   }

}

下面是 设置RecyclerView间距的关键方法

HashMap<String, Integer> stringIntegerHashMap = new HashMap<>();
stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.TOP_DECORATION,50);//top间距

stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.BOTTOM_DECORATION,100);//底部间距

stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.LEFT_DECORATION,50);//左间距

stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.RIGHT_DECORATION,100);//右间距

mRecyclerView.addItemDecoration(newRecyclerViewSpacesItemDecoration(stringIntegerHashMap));

可以根据自己的实际情况去设置想要的间距，也可以去单独设置
下面是设置间距后的效果图