如何获得像editText这样的用户输入然后插入数据库sqlite？

Question

当单击保存按钮插入到 sqlite 数据库时，我想获得像 editText 这样的用户输入。如何做到这一点。我正在寻找，但我找不到它。我正在编写一个记事本应用程序。参考image

    package com.suleymanemre.notepad;

import androidx.appcompat.app.AppCompatActivity;

import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class note extends AppCompatActivity {
    EditText editText;
    Button button;

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

        button= findViewById(R.id.save);
        editText = findViewById(R.id.editText);

    }
    public void save(View view){
        SQLiteDatabase noteDatabase = openOrCreateDatabase("Notes",MODE_PRIVATE,null);

        noteDatabase.execSQL("CREATE TABLE IF NOT EXISTS Notes(Notes VARCHAR);");

    }

    public void esc (View view){
        super.onBackPressed(); 
    }

}

Answer 1

您需要准备一个扩展 SQLiteOpenHelper 的类。

此链接可能有助于创建备忘录应用程序。

https://www.javahelps.com/2015/07/android-memo-application.html?m=1

Answer 2

如果您只想保存 1 个值，请考虑使用 SharedPreference：

SharedPreference mPref = context.getSharedPreferences(SETTINGS_NAME, Context.MODE_PRIVATE);
//get value
 return mPref.getString(Key.YOUR_KEY, DEFAULT_VALUE_IN_STRING);
//add value
SharedPreferences.Editor mEditor = mPref.edit();
mEditor.putString(Key.YOUR_KEY, YOUR_VALUE);
mEditor.commit()

如果你想使用 SQLite 数据库，考虑使用 Room：

将此添加到您的 build.gradle 文件中：

def room_version = "2.2.5"

  implementation "androidx.room:room-runtime:$room_version"
  annotationProcessor "androidx.room:room-compiler:$room_version"

创建您的数据库类：

@androidx.room.Dao
public interface MyDao {

    @Query("SELECT * FROM MyClass")
    List<MyClass> getAll();

    @Insert
    void insertAll(List<MyClass> mList);

    @Insert
    void insert(MyClass mItem);
}

创建您的应用数据库类：

@Database(entities = {MyClass.class}, version = 1)
public abstract class MyAppDatabase extends RoomDatabase {
    public abstract MyDao MyDao();
}

创建你的单例类：

public class MyDatabaseClient {

    private Context mCtx;
    private static MyDatabaseClient mInstance;

    private MyAppDatabase myAppDatabase;

    private MyDatabaseClient(Context mCtx) {
        this.mCtx = mCtx;
        myAppDatabase = Room.databaseBuilder(mCtx, MyClass.class, "MyDatabaseName").build();
    }

    public static synchronized MyDatabaseClient getInstance(Context mCtx) {
        if (mInstance == null) {
            mInstance = new MyDatabaseClient(mCtx);
        }
        return mInstance;
    }

    public MyAppDatabase getMyAppDatabase() {
        return myAppDatabase;

您的项目类别（随时添加新项目以保存或检索：

@Entity
public class MyClass implements Serializable {

    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "uid")
    public int uid;

    @ColumnInfo(name = "name")
    public String name;

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

用法：

//Get All
MyDatabaseClient.getInstance(getApplicationContext()).getMyAppDatabase().MyDao().getAll();

//Insert
final List<MyClass> mList = new ArrayList<>();
MyClass items = new MyClass();
items.setName("YOUR_VALUE");
mList.add(items);
MyDatabaseClient.getInstance(getApplicationContext()).getMyAppDatabase().MyDao().insertAll(mList);