編輯:關於Android編程
Android RecyclerView
小白今天第一次接觸RecyclerView,前輩大神告訴我這是一個很神奇的控件,一看就是一整天。
RecyclerView中有規定好的方法去顯示列表,圖片甚至視頻。還帶有刪除新建某一列表的方法。相對於ListView這個
RecyclerView控件就更加牛了。
明白的大神看一眼就懂,小白可以自己照源碼敲一遍看看效果。這段程序是把A-Z按列排列下來:
package com.example.osserver.recycler; import android.app.Activity; import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.support.v7.widget.*; import android.support.v7.widget.LinearLayoutManager; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import java.util.ArrayList; import java.util.List; public class MainActivity extends ActionBarActivity { private RecyclerView mRecyclerView; private List<String> mDatas; private HomeAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initData(); mRecyclerView = (RecyclerView)findViewById(R.id.id_recyclerview); mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); mRecyclerView.setAdapter(mAdapter = new HomeAdapter()); mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.HORIZONTAL_LIST)); } private void initData() { mDatas = new ArrayList<String>(); for (int i ='A';i<='Z';i++){ mDatas.add(""+(char)i); } } class HomeAdapter extends RecyclerView.Adapter<MyViewHolder> { @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { MyViewHolder holder = new MyViewHolder(LayoutInflater.from(MainActivity.this).inflate(R.layout.item,parent,false)); return holder; } @Override public void onBindViewHolder(MyViewHolder holder, int position) { holder.tv.setText(mDatas.get(position)); } @Override public int getItemCount() { return mDatas.size(); } } class MyViewHolder extends RecyclerView.ViewHolder { TextView tv; public MyViewHolder(View view) { super(view); tv = (TextView)view.findViewById(R.id.id_num); } } }
接下來就是列表的潤色部分:
今天我也只是進行到了這一步,踩了好多坑。
package com.zhy.sample.demo_recyclerview; /* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * limitations under the License. */ import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.RecyclerView.State; import android.util.Log; import android.view.View; /** * This class is from the v7 samples of the Android SDK. It's not by me! * <p/> * See the license above for details. */ public class DividerItemDecoration 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 DividerItemDecoration(Context context, int orientation) { final TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(0); 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) { Log.v("recyclerview - itemdecoration", "onDraw()"); 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); android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView(parent.getContext()); 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); 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); } } }
不能添加圖片,那就寫這些好了。
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