寒假学习14

Android Studio:RecyclerView

RecyclerView能够灵活实现大数据集的展示，视图的复用管理比ListView更好，能够实现列表、网格、瀑布流等形式，且不同的ViewHolder能够实现item多元化的功能。

MainActivity.java

package com.example.myapplicationfirst;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.RadioButton;

import com.example.myapplicationfirst.recyclerview.RecyclerViewActivity;

public class MainActivity extends AppCompatActivity {

    //声明空间
    private Button mBtnTextView;
    private Button mBtnButton;
    private Button mBtnEditText;
    private Button mBtnRadioButton;
    private Button mBtnCheckBox;
    private Button mBtnRecyclerView;

    //寻找事件
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mBtnTextView = findViewById(R.id.btn_textview);
        mBtnButton = findViewById(R.id.btn_button);
        mBtnEditText = findViewById(R.id.btn_edittext);
        mBtnRadioButton = findViewById(R.id.btn_radiobutton);
        mBtnCheckBox = findViewById(R.id.btn_checkbox);
        mBtnRecyclerView = findViewById(R.id.btn_recyclerview);
        setListeners();
    }

    //监听事件
    private void setListeners(){
        OnClick onClick = new OnClick();
        mBtnTextView.setOnClickListener(onClick);
        mBtnButton.setOnClickListener(onClick);
        mBtnEditText.setOnClickListener(onClick);
        mBtnRadioButton.setOnClickListener(onClick);
        mBtnCheckBox.setOnClickListener(onClick);
        mBtnRecyclerView.setOnClickListener(onClick);
    }

    //点击事件
    private class OnClick implements View.OnClickListener{

        @Override
        public void onClick(View v) {
            Intent intent = null;
            switch (v.getId()){
                case R.id.btn_textview:
                    //跳转到TextView演示界面
                    intent = new Intent(MainActivity.this,TextViewActivity.class);
                    break;
                case R.id.btn_button:
                    //跳转到Button演示界面
                    intent = new Intent(MainActivity.this,ButtonActivity.class);
                    break;
                case R.id.btn_edittext:
                    //跳转到EditText演示界面
                    intent = new Intent(MainActivity.this,EditTextActivity.class);
                    break;
                case R.id.btn_radiobutton:
                    //跳转到RadioButton演示界面
                    intent = new Intent(MainActivity.this, RadioButtonActivity.class);
                    break;
                case R.id.btn_checkbox:
                    //跳转到CheckBox演示界面
                    intent = new Intent(MainActivity.this, CheckBoxActivity.class);
                    break;
                case R.id.btn_recyclerview:
                    //跳转到RecyclerView演示界面
                    intent = new Intent(MainActivity.this, RecyclerViewActivity.class);
                    break;
            }
            startActivity(intent);
        }
    }
}

RecyclerViewActivity.java

package com.example.myapplicationfirst.recyclerview;

import androidx.appcompat.app.AppCompatActivity;

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

import com.example.myapplicationfirst.R;

public class RecyclerViewActivity extends AppCompatActivity {

    private Button mBtnLinear;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recycler_view);
        mBtnLinear = findViewById(R.id.btn_linear);
        //跳转
        mBtnLinear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(RecyclerViewActivity.this,LinearRecyclerViewActivity.class);
                startActivity(intent);
            }
        });
    }
}

LinearRecyclerViewActivity.java

package com.example.myapplicationfirst.recyclerview;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import com.example.myapplicationfirst.R;

public class LinearRecyclerViewActivity extends AppCompatActivity {

    private RecyclerView mRvMain;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_linear_recycler_view);
        mRvMain = findViewById(R.id.rv_main);
        mRvMain.setLayoutManager(new LinearLayoutManager(LinearRecyclerViewActivity.this));
        mRvMain.setAdapter(new LinearAdapter(LinearRecyclerViewActivity.this));
    }
}

LinearAdapter.java

package com.example.myapplicationfirst.recyclerview;

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

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.myapplicationfirst.R;

public class LinearAdapter extends RecyclerView.Adapter<LinearAdapter.LinearViewHolder> {

    private Context mContext;
    public LinearAdapter(Context context){
        this.mContext = context;
    }

    @NonNull
    @Override
    public LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        return new LinearViewHolder(LayoutInflater.from(mContext).inflate(R.layout.layout_linear_item,parent,false));
    }

    @Override
    public void onBindViewHolder(@NonNull LinearAdapter.LinearViewHolder holder, int position) {
        holder.textView.setText("Hello World");
    }

    @Override
    public int getItemCount() {
        return 30;
    }

    class LinearViewHolder extends RecyclerView.ViewHolder{

        private TextView textView;

        public LinearViewHolder(View itemView){
            super(itemView);
            textView = itemView.findViewById(R.id.tv_title);
        }
    }
}

res>layout>layout_linear_item.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:id="@+id/tv_type"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:textColor="#000"
        android:textSize="20sp"/>
</LinearLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical">

    <Button
        android:id="@+id/btn_textview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/btn_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/btn_edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="EditText"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/btn_radiobutton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="RadioButton"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/btn_checkbox"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="CheckBox"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/btn_recyclerview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="RecyclerView"
        android:textAllCaps="false"/>

</LinearLayout>

activity_recycler_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/btn_linear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="列表视图"/>

</LinearLayout>

activity_linear_recycler_view.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/colorPrimaryDark"/>

</RelativeLayout>