diff --git a/students/sec1814080911238/Fruit.java b/students/sec1814080911238/Fruit.java new file mode 100644 index 000000000..50feb1026 --- /dev/null +++ b/students/sec1814080911238/Fruit.java @@ -0,0 +1,19 @@ +package edu.hzuapps.androidlabs.sec1814080911238; + +public class Fruit { + private String name; + private String imageId; + + public Fruit(String name, String imageId) { + this.name = name; + this.imageId = imageId; + } + + public String getName() { + return name; + } + + public String getImageId() { + return imageId; + } +} diff --git a/students/sec1814080911238/FruitAdapter.java b/students/sec1814080911238/FruitAdapter.java new file mode 100644 index 000000000..1e2517a06 --- /dev/null +++ b/students/sec1814080911238/FruitAdapter.java @@ -0,0 +1,78 @@ +package edu.hzuapps.androidlabs.sec1814080911238; + +import android.content.SharedPreferences; +import android.view.LayoutInflater; +import android.view.View; +import android.view.ViewGroup; +import android.widget.Button; +import android.widget.ImageView; +import android.widget.TextView; +import android.widget.Toast; + +import androidx.annotation.NonNull; +import androidx.recyclerview.widget.RecyclerView; + +import java.util.List; + +import static android.content.Context.MODE_PRIVATE; + +public class FruitAdapter extends RecyclerView.Adapter { + private List mFruitList; + + static class ViewHolder extends RecyclerView.ViewHolder { + View fruitView; + TextView fruitImage; + TextView fruitName; + Button deleteBtn; + + public ViewHolder(View view) { + super(view); + fruitView = view; + fruitImage = view.findViewById(R.id.textView1); + fruitName = view.findViewById(R.id.textView2); + deleteBtn = view.findViewById(R.id.button); + } + } + + @NonNull + @Override + public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { + View view = LayoutInflater.from(parent.getContext()) + .inflate(R.layout.list_item, parent, false); + final ViewHolder holder = new ViewHolder(view); + + holder.deleteBtn.setOnClickListener(new View.OnClickListener() { + @Override + public void onClick(View view) { + //获取SharePreferences(参数1：文件名，参数2：模式) +// SharedPreferences sp = getSharedPreferences ("localData",MODE_PRIVATE); + //获取Editor对象 +// SharedPreferences.Editor editor = sp.edit (); + int position = holder.getAdapterPosition(); + Fruit fruit = mFruitList.get(position); + + Toast.makeText(view.getContext(), fruit.getName(), Toast.LENGTH_SHORT).show(); + + } + }); + return holder; + + } + + @Override + public void onBindViewHolder(@NonNull ViewHolder holder, int position) { + Fruit fruit = mFruitList.get(position); + holder.fruitImage.setText(fruit.getImageId()); + holder.fruitName.setText(fruit.getName()); + } + + @Override + public int getItemCount() { + return mFruitList.size(); + } + + public FruitAdapter(List fruitList) { + mFruitList = fruitList; + } + +} diff --git a/students/sec1814080911238/InputActivity.java b/students/sec1814080911238/InputActivity.java index 70725608b..6afad8051 100644 --- a/students/sec1814080911238/InputActivity.java +++ b/students/sec1814080911238/InputActivity.java @@ -1,25 +1,59 @@ package edu.hzuapps.androidlabs.sec1814080911238; -import android.app.Activity; -import android.content.Intent; +import android.content.SharedPreferences; import android.os.Bundle; import android.view.View; import android.widget.Button; +import android.widget.EditText; import android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; public class InputActivity extends AppCompatActivity { + private EditText str01,str02; + int num = 0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.input_activity); - final Activity thisActivity = this; + final InputActivity thisActivity = this; + Button btnOpen3 = (Button) findViewById(R.id.button3); + str01 = findViewById (R.id.editText1); + str02 = findViewById (R.id.editText2); btnOpen3.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { - Toast.makeText(InputActivity.this, "保存成功", Toast.LENGTH_LONG).show(); + //获取两个输入框的内容 + String string01 = str01.getText ().toString (); + String string02 = str02.getText ().toString (); + //将信息存储到SharePreferences + if(string01.equals ("") || string02.equals ("")){ //input框验证 + Toast.makeText (InputActivity.this,"单纯中英文不能为空",Toast.LENGTH_LONG).show (); + }else { //入库处理 + //获取SharePreferences(参数1：文件名，参数2：模式) + SharedPreferences sharedPreferences = getSharedPreferences ("localData",MODE_PRIVATE); + //获取Editor对象 + SharedPreferences.Editor editor = sharedPreferences.edit (); + //找到localData中最后一条，在最后一条数据后面进行num编号添加 + boolean flag = true; + while (flag) { + if(sharedPreferences.contains("English" + num)) { + num ++; + } else { + flag =false; + } + } + //存储信息 + editor.putString ("English" + num,string01); + editor.putString ("China" + num,string02); + //提交 + editor.commit (); + num++; + str01.setText(""); + str02.setText(""); + Toast.makeText (InputActivity.this,"保存成功",Toast.LENGTH_SHORT).show (); + } } }); } diff --git a/students/sec1814080911238/RememberActivity.java b/students/sec1814080911238/RememberActivity.java index b1ecbf853..a6afae853 100644 --- a/students/sec1814080911238/RememberActivity.java +++ b/students/sec1814080911238/RememberActivity.java @@ -1,13 +1,46 @@ package edu.hzuapps.androidlabs.sec1814080911238; +import android.content.Context; +import android.content.SharedPreferences; import android.os.Bundle; import androidx.appcompat.app.AppCompatActivity; +import androidx.recyclerview.widget.LinearLayoutManager; +import androidx.recyclerview.widget.RecyclerView; + +import java.util.ArrayList; +import java.util.List; public class RememberActivity extends AppCompatActivity { + private List fruitList = new ArrayList<>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.remember_activity); + + initFruits(); + RecyclerView recyclerView = findViewById(R.id.recycler_view); + LinearLayoutManager layoutManager= new LinearLayoutManager(this); + recyclerView.setLayoutManager(layoutManager); + FruitAdapter adapter = new FruitAdapter(fruitList); + recyclerView.setAdapter(adapter); } + private void initFruits() { + SharedPreferences sp = getSharedPreferences ("localData",MODE_PRIVATE); + + boolean flag = true; + int num = 0; + while (flag) { + if(sp.contains("English" + num)) { //判断localData中是否存在该数据，如何如果存在则通过Fruit渲染成列表 + System.out.println(sp.getString("English" + num,"")); + System.out.println( sp.getString("China" + num,"")); + Fruit apple = new Fruit(sp.getString("English" + num,""), sp.getString("China" + num,"")); // 创建 Fruit 对象 + fruitList.add(apple); // 将 apple 传入 fruitList 渲染类中 + num ++; //num++渲染下一个单词 + } else { + flag =false; + } + } + } + } diff --git a/students/sec1814080911238/input_activity.xml b/students/sec1814080911238/input_activity.xml index af6d80b11..04c798b9a 100644 --- a/students/sec1814080911238/input_activity.xml +++ b/students/sec1814080911238/input_activity.xml @@ -22,11 +22,11 @@ android:layout_height="20sp" android:layout_marginLeft="30dp" android:layout_marginTop="20dp" - android:text="单词英文" + android:text="单词" android:textSize="18sp"/> + android:text="翻译" /> - + + android:text="查看翻译" /> + \ No newline at end of file diff --git a/students/sec1814080911238/remember_activity.xml b/students/sec1814080911238/remember_activity.xml index 2ecf1bacf..e01c8112e 100644 --- a/students/sec1814080911238/remember_activity.xml +++ b/students/sec1814080911238/remember_activity.xml @@ -15,26 +15,10 @@ android:layout_height="wrap_content" android:orientation="vertical"> - - - - - - - - - - - - - - - - - - - - + diff --git a/students/sec1814080911238/report05.md b/students/sec1814080911238/report05.md new file mode 100644 index 000000000..71c62dab0 --- /dev/null +++ b/students/sec1814080911238/report05.md @@ -0,0 +1,277 @@ +# 实验五：Android存储编程 + +## 一、实验目标 + +- 了解Andoid的存储手段 +- 掌握Android的文件存储 +- 掌握Android的数据库存储 + +## 二、实验内容 + +- 将应用产生的数据保存到文件存储中； +- 说明使用的文件存储方式：内部 or 外部； +- 将运行结果截图。 + + +## 三、实验步骤 + +1. 通过提交按钮进行监听，获取输入框中的内容，同时做了为空校验，但未输入时，提示“单纯中英文不能为空”。 + +> InputActivity.java 文件 + +```java +... + btnOpen3.setOnClickListener(new View.OnClickListener() { + public void onClick(View view) { + //获取两个输入框的内容 + String string01 = str01.getText ().toString (); + String string02 = str02.getText ().toString (); + + if(string01.equals ("") || string02.equals ("")){ //输入框校验框验证 + Toast.makeText (InputActivity.this,"单纯中英文不能为空",Toast.LENGTH_LONG).show (); + }else { //入库处理 + ... + } + } + }); +... +``` + + + +2. 通过校验后，使用 `SharedPreferences` 进行存储， `SharedPreferences` 是基于XML文件存储 `key-value` 键值对数据，通常用来存储一些简单的配置信息。将单词和翻译存储位置在 `/data/data/edu.hzuapps.androidlabs.sec1814080911238/shared_prefs/localData.xml` 。同时为了保证每个单词 `key` 的唯一性（若key相同，则会覆盖原有的内容），使用 `sharedPreferences.contains` 和 `while` 循环来配合，确保key值的唯一性，最后进行入库处理。 + +> InputActivity .java 文件 + +```java +... +btnOpen3.setOnClickListener(new View.OnClickListener() { + public void onClick(View view) { + //获取两个输入框的内容 + String string01 = str01.getText ().toString (); + String string02 = str02.getText ().toString (); + //将信息存储到SharePreferences + if(string01.equals ("") || string02.equals ("")){ //input框验证 + Toast.makeText (InputActivity.this,"单纯中英文不能为空",Toast.LENGTH_LONG).show (); + }else { //入库处理 + //获取SharePreferences(参数1：文件名，参数2：模式) + SharedPreferences sharedPreferences = getSharedPreferences ("localData",MODE_PRIVATE); + //获取Editor对象 + SharedPreferences.Editor editor = sharedPreferences.edit (); + //找到localData中最后一条，在最后一条数据后面进行num编号添加 + boolean flag = true; + while (flag) { + if(sharedPreferences.contains("English" + num)) { + num ++; + } else { + flag =false; + } + } + //存储信息 + editor.putString ("English" + num,string01); + editor.putString ("China" + num,string02); + //提交 + editor.commit (); + num++; + str01.setText(""); + str02.setText(""); + Toast.makeText (InputActivity.this,"保存成功",Toast.LENGTH_SHORT).show (); + } + } +}); +... +``` + +> localData.xml 文件 + +```xml + + + AAA + sss + AA + a + B + a + A + a + a + b + +``` + + + +3. 在 *开始背单词* 页面，对刚刚录入的单词进行查看，同时点击翻译时，再次根据单词在 `localData.xml` 中查询对应的翻译，将翻译Toast出来，实现单词的背诵功能。 + +> RememberActivity.java 文件 + +```java +... + private void initFruits() { + SharedPreferences sp = getSharedPreferences ("localData",MODE_PRIVATE); + + boolean flag = true; + int num = 0; + while (flag) { + if(sp.contains("English" + num)) { //判断localData中是否存在该数据，如何如果存在则通过Fruit渲染成列表 + System.out.println(sp.getString("English" + num,"")); + System.out.println( sp.getString("China" + num,"")); + Fruit apple = new Fruit(sp.getString("English" + num,""), sp.getString("China" + num,"")); + fruitList.add(apple); + num ++; //num++渲染下一个单词 + } else { + flag =false; + } + } + } +... +``` + +4. 在渲染过程中发现了新的问题，之前在编写列表时，列表是通过引用封装的 `list_item.xml` ，进行多次调用，所渲染出来的静态数据，如今是动态数据，因为得使用动态的渲染方式。经过不断的摸索，在项目中使用了在support库中的 `androidx.recyclerview:recyclerview` 。 + +> remember_activity.xml + +```xml + + + + + + + + + + +``` + + + +5. 创建Fruit类，对单词数据进行抽象封装。 + +> Fruit.java + +```java +package edu.hzuapps.androidlabs.sec1814080911238; + +public class Fruit { + private String name; + private String imageId; + public Fruit(String name, String imageId) { + this.name = name; + this.imageId = imageId; + } + public String getName() { + return name; + } + public String getImageId() { + return imageId; + } +} +``` + + + +6. 封装fruitList类，将生成好的 `list_item.xml` 添加到 `androidx.recyclerview:recyclerview` 中进行渲染。 + +>fruitList.java + +```java +package edu.hzuapps.androidlabs.sec1814080911238; + +import android.content.SharedPreferences; +import android.view.LayoutInflater; +import android.view.View; +import android.view.ViewGroup; +import android.widget.Button; +import android.widget.ImageView; +import android.widget.TextView; +import android.widget.Toast; + +import androidx.annotation.NonNull; +import androidx.recyclerview.widget.RecyclerView; + +import java.util.List; + +import static android.content.Context.MODE_PRIVATE; + +public class FruitAdapter extends RecyclerView.Adapter { + private List mFruitList; + + static class ViewHolder extends RecyclerView.ViewHolder { + View fruitView; + TextView fruitImage; + TextView fruitName; + Button deleteBtn; + + public ViewHolder(View view) { + super(view); + fruitView = view; + fruitImage = view.findViewById(R.id.textView1); + fruitName = view.findViewById(R.id.textView2); + deleteBtn = view.findViewById(R.id.button); + } + } + @NonNull + @Override + public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { + View view = LayoutInflater.from(parent.getContext()) + .inflate(R.layout.list_item, parent, false); + final ViewHolder holder = new ViewHolder(view); + + holder.deleteBtn.setOnClickListener(new View.OnClickListener() { + @Override + public void onClick(View view) { + int position = holder.getAdapterPosition(); + Fruit fruit = mFruitList.get(position); + Toast.makeText(view.getContext(), fruit.getName(), Toast.LENGTH_SHORT).show(); + } + }); + return holder; + + } + @Override + public void onBindViewHolder(@NonNull ViewHolder holder, int position) { + Fruit fruit = mFruitList.get(position); + holder.fruitImage.setText(fruit.getImageId()); + holder.fruitName.setText(fruit.getName()); + } + @Override + public int getItemCount() { + return mFruitList.size(); + } + public FruitAdapter(List fruitList) { + mFruitList = fruitList; + } +} +``` + + + +## 四、实验结果 + +![入库保存](https://github.com/Arlene238/android-labs-2020/blob/master/students/sec1814080911238/lab5-1.png?raw=true) + +![查看保存数据](https://github.com/Arlene238/android-labs-2020/blob/master/students/sec1814080911238/lab5-2.png?raw=true) + +![渲染保存数据](https://github.com/Arlene238/android-labs-2020/blob/master/students/sec1814080911238/lab5-3.png?raw=true) + + + + + +## 五、实验心得 + + 此处实验，做的是存储功能，我选择了`SharedPreferences` 基于XML文件存储 `key-value` 键值对数据，`SharedPreferences` 的好处在于他体积小，方便本地存取，适合用来存放单词等文本类数据。在做的过程中也慢慢的发现了自己之前开发的不足，如列表方面，之前只是简单的静态数据的渲染，没有考虑到之后的动态渲染问题，在进过网上的资料查询和翻看教学资料，找到了使用 `androidx.recyclerview:recyclerview` 来动态渲染的解决方法。通过这次实验，个人的学习能力和开发能力得到了很好的锻炼和提升。