RecyclerView 设置item间隔和随机高度

在瀑布流中,如果item中的数据格式完全相同的话,和Grid的效果相同,所以我们要为item设置一个随机的高度

一.在onBindViewHolder()中为item设置随机高度

//修改瀑布流随机高度
Random random = new Random();
ViewGroup.LayoutParams layoutParams = holder.tv.getLayoutParams();
layoutParams.height=random.nextInt(200)+50;
holder.tv.setLayoutParams(layoutParams);

二.为item设置间隔

//RecycleView 增加边距
int spacingInPixels = 8;
mRecyclerView.addItemDecoration(new SpacesItemDecoration(spacingInPixels));

再添加一个增加间隔的类

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int space;

public SpacesItemDecoration(int space) {
this.space = space;
}

@Override
public void getItemOffsets(Rect outRect, View view,
RecyclerView parent, RecyclerView.State state) {
outRect.left = space;
outRect.right = space;
outRect.bottom = space;

// Add top margin only for the first item to avoid double space between items
if (parent.getChildPosition(view) == 0)
outRect.top = space;
}
}

三.在添加删除时报了一个java.lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v4/animation/AnimatorCompatHelper的错误

在moudle的gradle中添加如下代码:

configurations.all {

resolutionStrategy.eachDependency { DependencyResolveDetails details ->
def requested = details.requested
if (requested.group == 'com.android.support') {
if (!requested.name.startsWith("multidex")) {
details.useVersion '24.1.0'
}
}
}
}

RecyclerView的依赖

compile 'com.android.support:mediarouter-v7:25.0.0'
compile 'com.android.support:appcompat-v7:25.0.0'
compile 'com.android.support:recyclerview-v7:25.0.0'