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ListAdapter MyAdapter

程序员文章站 2022-03-20 23:01:16
ListAdapterpackage com.gcu.simple.adapter;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import com.bumpte...

ListAdapter

package com.gcu.simple.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

import com.bumptech.glide.Glide;
import com.gcu.simple.R;
import com.gcu.simple.model.ImageInfo;

import java.util.List;

public class ListAdapter extends BaseAdapter {
    List<ImageInfo> dataList;
    Context context;

    public ListAdapter(List<ImageInfo> dataList, Context context){
        this.dataList = dataList;
        this.context = context;
    }

    @Override
    public int getCount() {
        return dataList.size();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if(convertView == null) {
            viewHolder = new ViewHolder();
            LayoutInflater inflater = LayoutInflater.from(context);
            convertView = inflater.inflate(R.layout.item_list, null);
            convertView.setTag(viewHolder);

            viewHolder.imageView = convertView.findViewById(R.id.imageView);
        }else{
            viewHolder = (ViewHolder)convertView.getTag();
        }
        Glide.with(context).load(dataList.get(position).imageUrl).into(viewHolder.imageView);
        return convertView;
    }

    @Override
    public Object getItem(int position) {
        return dataList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    class ViewHolder {
        ImageView imageView;
    }

    public void update(List<ImageInfo> data){
        dataList = data;
        notifyDataSetChanged();
    }
}

MyAdapter

package com.gcu.simple.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.gcu.simple.R;

import java.util.List;

public class MyAdapter extends BaseAdapter {
    private List<String> contents;
    Context context;
    @Override
    public int getCount() {
        return contents.size();
    }

    @Override
    public Object getItem(int position) {
        return contents.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        if (convertView == null){
            // 初始化viewHolder
            viewHolder = new ViewHolder();
            LayoutInflater inflater = LayoutInflater.from(context);
            convertView = inflater.inflate(R.layout.item_list, null);
            convertView.setTag(viewHolder);

        }else{
            // 复用旧对象
            viewHolder = (ViewHolder)convertView.getTag();
        }
        // 设置textview内容
        viewHolder.textView.setText(contents.get(position));
        return convertView;
    }

    class ViewHolder {
        TextView textView;
    }
}

Model
imageinfo

package com.gcu.simple.model;

public class ImageInfo {
    public String imageUrl;
    public String text;

    public ImageInfo(String imageUrl, String text){
        this.imageUrl = imageUrl;
        this.text = text;
}
}

mymodel

package com.gcu.simple.model;

import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;

import java.util.List;

public class MyModel extends ViewModel {
    private MutableLiveData<String> msg;
    private MutableLiveData<Integer> count;

    private  MutableLiveData<List<ImageInfo>> data;

    public MutableLiveData<Integer> getCount() {
        if (count == null) {
            count = new MutableLiveData<>();
        }
        return count;
    }

    public MutableLiveData<String> getMsg() {
        if (msg == null) {
            msg = new MutableLiveData<>();
        }
        return msg;
    }

    public MutableLiveData<List<ImageInfo>> getData() {
       if(data == null){
           data = new MutableLiveData<>();
       }
        return data;
    }
}

NETWORK
infoActivity

package com.gcu.simple;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.os.Bundle;

public class InfoActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_info);

        Toolbar myToolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(myToolbar);
    }
}

InfoFragment

package com.gcu.simple;

import android.content.Intent;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;

import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;

import com.gcu.simple.model.MyModel;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link InfoFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class InfoFragment extends Fragment {
    private MyModel model;
    EditText editText;
    TextView textView;
    public InfoFragment() {
        // Required empty public constructor
    }

    // TODO: Rename and change types and number of parameters
    public static InfoFragment newInstance() {
        InfoFragment fragment = new InfoFragment();
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        model = new ViewModelProvider(getActivity()).get(MyModel.class);

        model.getMsg().observe(getActivity(), new Observer<String>() {
            @Override
            public void onChanged(String s) {
                textView.setText(s);
            }
        });
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        textView = view.findViewById(R.id.info_text);
        editText = view.findViewById(R.id.editTextInput);

        editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                model.getMsg().setValue(s.toString());
            }
        });

        Intent intent = getActivity().getIntent();
        String msg = intent.getStringExtra(MainActivity.INFOKEY);
        textView.setText(msg);
        editText.setText(msg);


    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_info, container, false);
    }
}

ListActivity

package com.gcu.simple;

import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;

import android.database.Observable;
import android.os.Bundle;
import android.util.Log;

import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.bumptech.glide.Glide;
import com.gcu.simple.adapter.ListAdapter;
import com.gcu.simple.model.ImageInfo;
import com.gcu.simple.model.MyModel;
import com.gcu.simple.network.MySingleton;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class ListActivity extends AppCompatActivity {
    MyModel model;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);

        model = new ViewModelProvider(this).get(MyModel.class);

        ListView listView = findViewById(R.id.listView);
        final ListAdapter adapter = new ListAdapter(new ArrayList<ImageInfo>(), getApplicationContext());
        listView.setAdapter(adapter);

        model.getData().observe(this, new Observer<List<ImageInfo>>(){

            @Override
            public void onChanged(List<ImageInfo> imageInfos) {
                if (imageInfos == null)
                    return;
                adapter.update(imageInfos);
            }
        });

        //Glide.with(getApplicationContext()).load(dataList.get(position).imageUrl).into(ListAdapter.ViewHolder.imageView);
        getData();
    }

    void getData() {
        RequestQueue queue = MySingleton.getInstance(this.getApplicationContext()).
                getRequestQueue();

        String url = "https://bing.getlove.cn/latelyBingImageStory";
        JsonArrayRequest jsonObjectRequest = new JsonArrayRequest
                (Request.Method.GET, url, null, new Response.Listener<JSONArray>() {


                    @Override
                    public void onResponse(JSONArray response) {
                        //textView.setText("Response: " + response.toString());
                        Log.v("awtt1", String.format("111:%s", response.toString()));
                        JSONArray ar = null;
                        try {
                            ar = response;
                            Log.v("awtt1", String.format("111:%d", ar.length()));
                            List<ImageInfo> rets = new ArrayList<>();
                            for (int i = 0; i < ar.length(); i++) {
                                JSONObject item = ar.getJSONObject(i);
                                String text = item.getString("copyright");
                                String url = item.getString("CDNUrl");
                                url = String.format("https:%s", url);
                                rets.add(new ImageInfo(url, text));
                                Log.v("awtt1", String.format("%s, %s", url, text));
                            }
                            model.getData().setValue(rets);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(getApplicationContext(), String.format("网络错误：%s", error), Toast.LENGTH_SHORT).show();
                        Log.e("wtt", String.format("%s", error));
                    }

                });
        queue.add(jsonObjectRequest);



    }

    void getData2(){
        final TextView textView = (TextView) findViewById(R.id.text);
        // ...

        // 初始化 RequestQueue.
        RequestQueue queue2 = Volley.newRequestQueue(this);

        // 发起一个StringRequest 请求指定网址
        StringRequest stringRequest = new StringRequest(Request.Method.GET, "https://www.gcu.edu.cn/main.htm",
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        // 在textview控件上显示最多500个字符的内容
                        textView.setText("Response is: "+ response.substring(0,500));
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                // 有错误是，显示： 请求数据报错!
                textView.setText("请求数据报错!");
            }
        });

        // 放置到调度队列.
        queue2.add(stringRequest);
    }
}

MainActivity

package com.gcu.simple;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    public static final String INFOKEY = "com.gcu.simple.infokey";
    TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = findViewById(R.id.textView);
    }

    public void openMessage(View view){
        Intent intent = new Intent(this, InfoActivity.class);
        String msg = textView.getText().toString();
        intent.putExtra(INFOKEY, msg);
        startActivity(intent);
    }

    public void listBtn(View view){
        Intent intent = new Intent(this, ListActivity.class);
        startActivity(intent);
    }
}

STYLE

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    </style>

    <style name="button_text" parent="TextAppearance.AppCompat.Widget.ActionBar.Title">
        <item name="android:textSize">20sp</item>
        <item name="android:textColor">#FF0000</item>
        <item name="android:textStyle">italic</item>

    </style>

    <style name="button_text.mytextstyle" >
        <item name="android:textSize">30sp</item>
        <item name="android:textStyle">bold</item>
    </style>
</resources>

LAYOUT
activity_info.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".InfoActivity">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <fragment
        android:id="@+id/fragment"
        android:name="com.gcu.simple.InfoFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/toolbar" />
</androidx.constraintlayout.widget.ConstraintLayout>

activity_list.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".ListActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="1dp"
        android:layout_marginEnd="1dp"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="1.0">

        <Button
            android:id="@+id/btn_msg"
            android:text="查看消息"
            android:onClick="openMessage"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp"
             />

        <TextView
            android:id="@+id/textView"
            android:text="什么都没有"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
             />

        <Button
            android:id="@+id/btn_data"
            android:text="数据更新及列表"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:onClick="listBtn"
             />

        <Button
            android:id="@+id/btn_style"
            style="@style/button_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="使用样式" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

fragment_info.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/infoLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".InfoFragment">

    <!-- TODO: Update blank fragment layout -->

    <TextView
        android:id="@+id/info_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="@string/hello_blank_fragment"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/editTextInput"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/info_text" />

</androidx.constraintlayout.widget.ConstraintLayout>

item_list.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@tools:sample/avatars" />
</androidx.constraintlayout.widget.ConstraintLayout>

本文地址：https://blog.csdn.net/weixin_43865875/article/details/110583408

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