RecycleView是google为了优化listview，gridview 提供的一个新的控件。
1.android 导入recycleview
在app的gradle里面加入：
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
apt "org.androidannotations:androidannotations:$AAVersion"
compile "org.androidannotations:androidannotations-api:$AAVersion"
testCompile 'junit:junit:4.12'
compile 'com.android.support:recyclerview-v7:23.1.+'
compile 'com.android.support:appcompat-v7:23.1.1'
}
其中23为sdk版本号。
2.使用RecycleView
RecycleView主要功能分为几个模块：
adapter 的功能与以前类似。
package com.joyfulmath.sample.javanetwork.androidbase.recycleview.view; import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView; import com.joyfulmath.sample.javanetwork.R; import java.util.ArrayList; /**
* @author deman.lu
* @version on 2016-03-10 14:19
*/
public class RecycleAdapter extends RecyclerView.Adapter<RecycleAdapter.RecycleViewHolder> { private Context context;
private ArrayList<String> mDatas;
public RecycleAdapter(Context context,ArrayList<String> mStrings)
{
this.context = context;
this.mDatas = mStrings;
} @Override
public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecycleViewHolder holder = new RecycleViewHolder(LayoutInflater.from(context)
.inflate(R.layout.item_list,parent,false));
return holder;
} @Override
public void onBindViewHolder(RecycleViewHolder holder, int position) {
holder.tv1.setText(mDatas.get(position));
holder.tv2.setText(mDatas.get(position)+" demo");
} @Override
public int getItemCount() {
return mDatas.size();
} class RecycleViewHolder extends RecyclerView.ViewHolder
{
TextView tv1;
TextView tv2;
public RecycleViewHolder(View itemView) {
super(itemView);
tv1 = (TextView) itemView.findViewById(R.id.tv_1);
tv2 = (TextView) itemView.findViewById(R.id.tv_2);
}
}
}
首先 需要定义一个holder，这个holder是用来优化复用recycleview的item的。此与listview已经非常类似。
其次adapter要实现3个方法：
public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) //viewholder 布局代码
public void onBindViewHolder(RecycleViewHolder holder, int position) 数据处理代码
public int getItemCount() 得到item size
相当熟悉的代码。
LayoutManager:
RecycleView 默认支持linearlayoutmanager & gridlayoutmanager
其实就是对应listview & gridview
mRcyV.setLayoutManager(new LinearLayoutManager(this));
void afterView()
{
mPresenter = new RecyclePresenter();
mRcyV.setLayoutManager(new GridLayoutManager(this,4));
mRcyV.setAdapter(new RecycleAdapter(this, mPresenter.getData()));
mRcyV.addItemDecoration(new RecycleGridItemDecoration(this));
}
ItemDectoration:
本质上是每个itemview的子view。很多时候用途就是定义为 分隔线使用。
1.listview.
public class RecycleItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private Drawable mDivider;
private int mOrientation;
public RecycleItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = new ColorDrawable(Color.argb(0xff,0xff,0x22,0x33));
a.recycle();
setOrientation(orientation);
}
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) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
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+10);
mDivider.draw(c);
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
}
}
}
2.gridview 样式：
public class RecycleGridItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[] { android.R.attr.listDivider };
private Drawable mDivider;
public RecycleGridItemDecoration(Context context)
{
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state)
{
drawHorizontal(c, parent);
drawVertical(c, parent);
}
private int getSpanCount(RecyclerView parent)
{
// 列数
int spanCount = -1;
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager)
{
spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
} else if (layoutManager instanceof StaggeredGridLayoutManager)
{
spanCount = ((StaggeredGridLayoutManager) layoutManager)
.getSpanCount();
}
return spanCount;
}
public void drawHorizontal(Canvas c, RecyclerView parent)
{
int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++)
{
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int left = child.getLeft() - params.leftMargin;
final int right = child.getRight() + params.rightMargin
+ mDivider.getIntrinsicWidth();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawVertical(Canvas c, RecyclerView parent)
{
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++)
{
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int top = child.getTop() - params.topMargin;
final int bottom = child.getBottom() + params.bottomMargin;
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
int childCount)
{
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager)
{
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
return true;
}
} else if (layoutManager instanceof StaggeredGridLayoutManager)
{
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
if (orientation == StaggeredGridLayoutManager.VERTICAL)
{
if ((pos + 1) % spanCount == 0)// 如果是最后一列，则不需要绘制右边
{
return true;
}
} else
{
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一列，则不需要绘制右边
return true;
}
}
return false;
}
private boolean isLastRaw(RecyclerView parent, int pos, int spanCount,
int childCount)
{
RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
if (layoutManager instanceof GridLayoutManager)
{
childCount = childCount - childCount % spanCount;
if (pos >= childCount)// 如果是最后一行，则不需要绘制底部
return true;
} else if (layoutManager instanceof StaggeredGridLayoutManager)
{
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation();
// StaggeredGridLayoutManager 且纵向滚动
if (orientation == StaggeredGridLayoutManager.VERTICAL)
{
childCount = childCount - childCount % spanCount;
// 如果是最后一行，则不需要绘制底部
if (pos >= childCount)
return true;
} else
// StaggeredGridLayoutManager 且横向滚动
{
// 如果是最后一行，则不需要绘制底部
if ((pos + 1) % spanCount == 0)
{
return true;
}
}
}
return false;
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition,
RecyclerView parent)
{
int spanCount = getSpanCount(parent);
int childCount = parent.getAdapter().getItemCount();
if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行，则不需要绘制底部
{
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
} else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列，则不需要绘制右边
{
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else
{
outRect.set(0, 0, mDivider.getIntrinsicWidth(),
mDivider.getIntrinsicHeight());
}
}
}
最后是activity页面：
@EActivity(R.layout.activity_recycleview_demo)
public class RecycleViewDemo extends Activity{
@ViewById(R.id.act_solution_1_lv)
RecyclerView mRcyV; RecyclePresenter mPresenter; @AfterViews
void afterView()
{
mPresenter = new RecyclePresenter();
mRcyV.setLayoutManager(new GridLayoutManager(this,4));
mRcyV.setAdapter(new RecycleAdapter(this, mPresenter.getData()));
mRcyV.addItemDecoration(new RecycleGridItemDecoration(this));
}
}
ItemAnimator：
recycleview的每一个item的add & delete都是可配置动画的。DefaultItemAnimator是google提供的默认实现方式。
mRcyV.setItemAnimator(new DefaultItemAnimator());
public void addData(int position) {
mDatas.add(position, "Insert One");
notifyItemInserted(position);
}
public void removeData(int position) {
mDatas.remove(position);
notifyItemRemoved(position);
}
在adapter中实现这2个方法，关键在于notifyItem***， 这2个方法可以触发动画。
recycleview比起listview来说，应该是可以定制更多的东西，尤其是瀑布模式，实现起来效果很炫。
参考：
http://blog.csdn.net/lmj623565791/article/details/45059587