列表中使用Picasso加载图片滑动列表时加载效率优化解决滑动卡顿问题

1、ListView优化:

重新自定义ScrollListener并设置滑动事件

mListView.setOnScrollListener(new ScrollListenerListView(this));

自定义的ScrollListener如下:

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import android.widget.AbsListView;

import com.manyiaby.view.viewutils.LogUtil;

import com.squareup.picasso.Picasso;

/**

* 列表滚动时Picasso暂停加载停止滚动时恢复加载事件

* Created by ${cd} on 2018/1/29.

*/

public class ScrollListenerListView implements AbsListView.OnScrollListener{

private String TAG = getClass().getSimpleName();

private final Context context;

/**
* 列表滚动时Picasso暂停加载停止滚动时恢复加载事件
* @param context
*/
public ScrollListenerListView(Context context) {
this.context = context;
}

/**
* @param view e.g:ListView
* @param scrollState
*  0（SCROLL_STATE_IDLE）表示ListView是不动的（The AbsListView is not currently scrolling.）
*  1（SCROLL_STATE_DRAGGING）表示ListView正在被拖拽（The AbsListView is currently being dragged by outside input such as user touch input.）
*  2（SCROLL_STATE_SETTLING）表示ListView正在惯性下滚动（The AbsListView is currently animating to a final position while not under outside control.）
*/
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
LogUtil.i(TAG,"=====" + scrollState);
final Picasso picasso = Picasso.with(context);
if (scrollState == SCROLL_STATE_IDLE || scrollState == SCROLL_STATE_TOUCH_SCROLL) {
picasso.resumeTag(context);//在停止滚动/正在滚动的时候调用,停止滚动时恢复图片加载
} else {
picasso.pauseTag(context);//列表滑动的时候调用,停止加载图片
}
}

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
int totalItemCount) {
// Do nothing.
}

}

2、RecyclerView优化:

重新自定义ScrollListener并设置滑动事件

mRecyclerView.addOnScrollListener(new ScrollListenerRecyclerView(this));

自定义的ScrollListener如下:

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import com.manyiaby.view.viewutils.LogUtil;

import com.squareup.picasso.Picasso;

import static android.support.v7.widget.RecyclerView.SCROLL_STATE_SETTLING;

/**

* 列表滚动时Picasso暂停加载停止滚动时恢复加载事件

* Created by ${cd} on 2018/1/29.

*/

public class ScrollListenerRecyclerView extends RecyclerView.OnScrollListener{

private String TAG = getClass().getSimpleName();

private final Context context;

/**
* 列表滚动时Picasso暂停加载停止滚动时恢复加载事件
* @param context
*/
public ScrollListenerRecyclerView(Context context) {
this.context = context;
}

/**
* @param recyclerView
* @param scrollState
*  0（SCROLL_STATE_IDLE）表示recyclerView是不动的（The recyclerView is not currently scrolling.）
*  1（SCROLL_STATE_DRAGGING）表示recyclerView正在被拖拽（The recyclerView is currently being dragged by outside input such as user touch input.）
*  2（SCROLL_STATE_SETTLING）表示recyclerView正在惯性下滚动（The recyclerView is currently animating to a final position while not under outside control.）
*/
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int scrollState) {
super.onScrollStateChanged(recyclerView,scrollState);
LogUtil.i(TAG,"=====" + scrollState);
final Picasso picasso = Picasso.with(context);
if(scrollState == SCROLL_STATE_SETTLING){
picasso.pauseTag(context);//列表滑动的时候调用,停止加载图片
}else{
picasso.resumeTag(context);//在停止滚动/正在滚动的时候调用,停止滚动时恢复图片加载
}
}

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
}

}

补充：

1、注意ListView中和RecyclerView中的设置方法不同

ListView:setOnScrollListener

RecyclerView：addOnScrollListener

2、ListView中和RecyclerView的自定义ScrollListener不同

ListView：ScrollListenerListView implements AbsListView.OnScrollListener

RecyclerView：ScrollListenerRecyclerView extends RecyclerView.OnScrollListener

ListView重写ScrollListener需要实现OnScrollListener接口（这个可以由源码验证）

RecyclerView重写ScrollListener需要继承抽象类OnScrollListener（这个可以由源码验证）