java - Android java中的回收视图
问题描述
Recycler View 没有迭代到数组的长度。这是代码,我错过了什么。我遵循了描述整个过程的指南,在该指南中,数组的所有项目都在列表视图中可见。这是承载 recyclerView 的主要活动文件,位于通过数组过滤并弹出列表视图的适配器 java 类下方。请帮我
PickupActivity.java
package com.demo.driverconsole;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerViewAccessibilityDelegate;
import android.util.Log;
import android.widget.Adapter;
import android.widget.Toast;
import java.util.ArrayList;
public class pickupActivity extends AppCompatActivity {
private static final String TAG = "pickupActivity";
private RecyclerView studentList;
private RecyclerView.Adapter adapter;
private RecyclerView.LayoutManager layoutManager;
private ArrayList<String> myDataset = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pickup);
myDataset.add("John Doe");
myDataset.add("Jane Doe");
myDataset.add("Susan");
initRecycler();
}
public void initRecycler() {
Log.d(TAG, "Called");
RecyclerView recyclerView = findViewById(R.id.recyclerView);
StudentListAdapter adapter = new StudentListAdapter(myDataset);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
}
}
StudentListAdapter.java
package com.datastoneglobal.driverconsole;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
import java.util.ArrayList;
public class StudentListAdapter extends RecyclerView.Adapter<StudentListAdapter.ViewHolder> {
private static final String TAG = "StudentListAdapter";
private ArrayList<String> names = new ArrayList<>();
public StudentListAdapter(ArrayList<String> names) {
Log.d(TAG, "StudentListAdapter: " + names);
this.names = names;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.student_item, parent, false);
ViewHolder vh = new ViewHolder(view);
return vh;
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.text.setText(names.get(position));
}
@Override
public int getItemCount() {
return names.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView text;
RelativeLayout layout;
public ViewHolder(View itemView) {
super(itemView);
text = itemView.findViewById(R.id.textView);
}
}
}
活动拾取.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:layout_height="wrap_content" android:layout_width="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
</RelativeLayout>
学生项目.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/layout"
android:layout_height="match_parent">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:text="Loading ...">
</TextView>
</RelativeLayout>
解决方案
RelativeLayout
代码看起来正确我发现的唯一问题是你的 高度StudentItem.xml
将您的高度更改RelativeLayout
为android:layout_height="wrap_content"
StudentItem.xml
示例代码
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/layout"
android:layout_height="wrap_content">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:text="Loading ...">
</TextView>
</RelativeLayout>
编辑
用这个
private StudentListAdapter adapter;
而不是这个
private RecyclerView.Adapter adapter;
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