老师,我遇到了一个非常奇葩的问题，recyclerview 中的item match_parent不起作用！！！！
//由于我的AS更新到了最细版本,在新建项目的时候没有选择compile version的界面了,默认就是最新的6.0
//下面的是activity_main布局文件
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
//content_main.xml布局文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="@layout/activity_main">
<android.support.v7.widget.RecyclerView
android:id="@+id/rv"
android:layout_width="match_parent"
android:layout_height="200dp"></android.support.v7.widget.RecyclerView>
</RelativeLayout>
//item.xml文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="72dp"
android:background="#44ff0000">
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center" />
</FrameLayout>
//MainActivity代码
package com.lee.taylor.recyclerview;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<String> mDatas;//数据源
private RecyclerView mRv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
initDatas();
initView();
mRv.setAdapter(new SimpleAdapter(mDatas, this));
LinearLayoutManager manager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, true);
mRv.setLayoutManager(manager);
}
private void initView() {
mRv = (RecyclerView) findViewById(R.id.rv);
}
private void initDatas() {
mDatas = new ArrayList<>();
for (int i = 'A'; i < 'z'; i++) {
mDatas.add("" + (char) i);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
//SimpleAdapter
package com.lee.taylor.recyclerview;
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 java.util.List;
/**
* Created by Taylor on 2015/10/9.
*/
public class SimpleAdapter extends RecyclerView.Adapter<SimpleAdapter.MyViewHolder> {
private List<String> mDatas;
private LayoutInflater mInflater;
public SimpleAdapter(List<String> mDatas, Context context) {
this.mDatas = mDatas;
this.mInflater = LayoutInflater.from(context);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
/**
* 此处inflate的时候 ,如果是mInflater.inflate(R.layout.listview_item, parent);会报如下错误
*
* The specified child already has a parent. You must call removeView() on the child's parent first
*
* 它说这个特定的child已经有一个parent了，你必须在这个parent中首先调用removeView()方法，才能继续你的内容。
*
* 这里很明显这个child是一个View，一个子（child）View必须依赖于父（parent）View，如果你要使用这个child，
*
* 则必须通过parent，而你如果就是硬想使用这个child，那么就得让这个child与parent脱离父子关系（即removeView（））
*/
View convertView = mInflater.inflate(R.layout.listview_item, null);
MyViewHolder viewHolder = new MyViewHolder(convertView);
return viewHolder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.tv.setText(mDatas.get(position));
}
@Override
public int getItemCount() {
return mDatas.size();
}
/**
* RecyclerView的ViewHolder
*/
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView tv;
public MyViewHolder(View itemView) {
super(itemView);
tv = (TextView) itemView.findViewById(R.id.tv);
}
}
}
recyclerview中item的宽度就是没办法matchparent ，这是为什么呢？
/**
*我在SimpleAdapter中重新设置了convertView的LayoutParams,item才能match_parent
*修改后的SimpleAdapter
*/
package com.lee.taylor.recyclerview;
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 java.util.List;
/**
* Created by Taylor on 2015/10/9.
*/
public class SimpleAdapter extends RecyclerView.Adapter<SimpleAdapter.MyViewHolder> {
private List<String> mDatas;
private LayoutInflater mInflater;
public SimpleAdapter(List<String> mDatas, Context context) {
this.mDatas = mDatas;
this.mInflater = LayoutInflater.from(context);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
/**
* 此处inflate的时候 ,如果是mInflater.inflate(R.layout.listview_item, parent);会报如下错误
*
* The specified child already has a parent. You must call removeView() on the child's parent first
*
* 它说这个特定的child已经有一个parent了，你必须在这个parent中首先调用removeView()方法，才能继续你的内容。
*
* 这里很明显这个child是一个View，一个子（child）View必须依赖于父（parent）View，如果你要使用这个child，
*
* 则必须通过parent，而你如果就是硬想使用这个child，那么就得让这个child与parent脱离父子关系（即removeView（））
*/
View convertView = mInflater.inflate(R.layout.listview_item, null);
//如果想让item match_parent 必须setLayoutParams 在布局中match_parent不起作用,暂时不知道为什么,(有可能是mInflater.inflate(R.layout.listview_item, null);的原因)
convertView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 72));//加了这一句话,可以match_parent了
MyViewHolder viewHolder = new MyViewHolder(convertView);
return viewHolder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.tv.setText(mDatas.get(position));
}
@Override
public int getItemCount() {
return mDatas.size();
}
/**
* RecyclerView的ViewHolder
*/
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView tv;
public MyViewHolder(View itemView) {
super(itemView);
tv = (TextView) itemView.findViewById(R.id.tv);
}
}
}
