Android 无法设置回收器视图
我一直在使用ListView,现在正在试用Recycler视图。我一直试图按照基本设置的文档进行操作,但令人沮丧的是无法做到这一点 ViewHolder类应该接受一个TextView参数,但在文档站点中,示例是输入一个视图作为参数,我不知道该如何工作。我试图用TextView强制转换它,得到一个ClassCastException。我已经在上面的一行中进行了注释,它给出了阻止我编译的错误。错误在MyAdapter类中 我很抱歉,如果我只是不善于阅读文件,否则这显然是荒谬的来自一个官方网站 主要活动Android 无法设置回收器视图,android,android-recyclerview,Android,Android Recyclerview,我一直在使用ListView,现在正在试用Recycler视图。我一直试图按照基本设置的文档进行操作,但令人沮丧的是无法做到这一点 ViewHolder类应该接受一个TextView参数,但在文档站点中,示例是输入一个视图作为参数,我不知道该如何工作。我试图用TextView强制转换它,得到一个ClassCastException。我已经在上面的一行中进行了注释,它给出了阻止我编译的错误。错误在MyAdapter类中 我很抱歉,如果我只是不善于阅读文件,否则这显然是荒谬的来自一个官方网站 主要活
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
String[] myDataset = {"item 1", "item 2"};
mAdapter = new MyAdapter(myDataset);
mRecyclerView.setAdapter(mAdapter);
}
}
MyAdapter类
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public ViewHolder(TextView v) {
super(v);
mTextView = v;
}
}
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, parent, false);
//THIS is the line causing error. v is View. I should be inputting a textview.
ViewHolder vh = new ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mTextView.setText(mDataset[position]);
}
@Override
public int getItemCount() {
return mDataset.length;
}
}
导入android.support.v7.widget.RecyclerView;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.TextView;
公共类MyAdapter扩展了RecyclerView.Adapter{
私有字符串[]mDataset;
公共静态类ViewHolder扩展了RecyclerView.ViewHolder{
公共文本视图mTextView;
公共视图持有者(文本视图v){
超级(五);
mTextView=v;
}
}
公共MyAdapter(字符串[]myDataset){
mDataset=myDataset;
}
@凌驾
public MyAdapter.ViewHolder onCreateViewHolder(视图组父级,
int视图类型){
视图v=LayoutInflater.from(parent.getContext())
.充气(R.layout.my_text_视图,父视图,false);
//这是导致错误的行。v是视图。我应该输入文本视图。
视窗支架vh=新视窗支架(v);
返回vh;
}
@凌驾
公共无效onBindViewHolder(ViewHolder,int位置){
holder.mTextView.setText(mDataset[position]);
}
@凌驾
public int getItemCount(){
返回mDataset.length;
}
}
我的文本视图xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/textView" />
</LinearLayout>
您的取景器必须如下所示:
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public ViewHolder(View v) {
super(v);
mTextView = v.findViewById(R.id.textViewId);
}
}
别忘了将android:id=“@+id/textViewId”放在布局中的文本视图中您将从充气机中获得一个
线性布局
:
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, parent, false);
// v <- LinearLayout
public ViewHolder(View v) {
mTextView = (TextView) v.findViewById(R.id.text);
}
您可以执行以下操作之一。或者将
ViewHolder
类的构造函数更改为参数aView
,如下所示
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView mTextView;
public ViewHolder(View v) {
super(v);
}
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
vh.name = (TextView) v.findViewById(R.id.textView);
return vh;
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
TextView mTextView = (TextView) v.findViewById(R.id.textview);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(mTextView);
return vh;
}
然后像这样更改onCreateViewHolder
方法
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView mTextView;
public ViewHolder(View v) {
super(v);
}
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
vh.name = (TextView) v.findViewById(R.id.textView);
return vh;
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
TextView mTextView = (TextView) v.findViewById(R.id.textview);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(mTextView);
return vh;
}
或者您可以保留构造函数,并像这样更改onCreateViewHolder
方法
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView mTextView;
public ViewHolder(View v) {
super(v);
}
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
vh.name = (TextView) v.findViewById(R.id.textView);
return vh;
}
@Override
public MemebershipAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.site_item, parent, false);
TextView mTextView = (TextView) v.findViewById(R.id.textview);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(mTextView);
return vh;
}
因此,请输入
TextView
。请提供R.layout.my\u text\u view
-我假设它看起来像
。从textview中删除包装布局,它应该可以工作。@DavidMedenjak如果我放入textview,那么如何传入视图v?添加了xmlATextView扩展视图
,View
是它的超类,您可以在它的位置使用TextView
。请提供前面提到的布局xml。删除linearlayout,将名称空间添加到textview,它应该work@DavidMedenjak对不起,我不明白。我理解观点是超级阶级。但我必须通过那个充气机。你的意思是不是说视图v=布局更平坦。。。使用文本视图v=LayoutInflater。。。如果没有,请给我举个例子。我将删除线性。使用选项2。作品谢谢