Android学习进度四

Posted 2021-03-13 嘉禾旧木

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Android学习进度四相关的知识，希望对你有一定的参考价值。

经过一段时间观看视频进行android的学习，将现今所学知识进行阶段性总结编写了一款口算测试App，并成功将其打包成apk在手机上运行。主要使用了LiveData,DataBinding,ViewModel以及Fragment等，话不多说，上代码。

一.界面的搭建

创建四个界面，分别为TitleFragment,QuestionFragment,WinFragment以及LoseFragment

因为使用了DataBinding和LiveData，要在build.gradle中添加依赖

dataBinding.enabled true

implementation \'androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha02\'//最新的依赖可以在官网中找到

创建MyViewModel.java，继承自AndroidViewModel

package com.example.calculationtest;

import android.app.Application;
import android.content.Context;
import android.content.SharedPreferences;

import androidx.annotation.NonNull;
import androidx.lifecycle.AndroidViewModel;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.SavedStateHandle;

import java.util.Random;

public class MyViewModel extends AndroidViewModel {
    private SavedStateHandle handle;
    private static String KEY_HIGH_SCORE = "key_high_score";
    private static String KEY_LEFT_NUMBER = "key_left_number";
    private static String KEY_RIGHT_NUMBER = "key_right_number";
    private static String KEY_OPERATOR = "key_operator";
    private static String KEY_ANSWER = "key_answer";
    private static String SAVE_SHP_DATA_NAME = "save_shp_data_name";
    private static String KEY_CURRENT_SCORE = "key_current_score";
    boolean win_flag = false;

    public MyViewModel(@NonNull Application application, SavedStateHandle handle) {
        super(application);
        if (!handle.contains(KEY_HIGH_SCORE)) {
            SharedPreferences shp = getApplication().getSharedPreferences(SAVE_SHP_DATA_NAME, Context.MODE_PRIVATE);
            handle.set(KEY_HIGH_SCORE, shp.getInt(KEY_HIGH_SCORE, 0));
            handle.set(KEY_LEFT_NUMBER, 0);
            handle.set(KEY_RIGHT_NUMBER, 0);
            handle.set(KEY_OPERATOR, "+");
            handle.set(KEY_ANSWER, 0);
            handle.set(KEY_CURRENT_SCORE, 0);
        }
        this.handle = handle;
    }

    public MutableLiveData<Integer> getLeftNumber() {
        return handle.getLiveData(KEY_LEFT_NUMBER);
    }

    public MutableLiveData<Integer> getRightNumber() {
        return handle.getLiveData(KEY_RIGHT_NUMBER);
    }

    public MutableLiveData<String> getOpreator() {
        return handle.getLiveData(KEY_OPERATOR);
    }

    public MutableLiveData<Integer> getHighScore() {
        return handle.getLiveData(KEY_HIGH_SCORE);
    }

    public MutableLiveData<Integer> getCurrentScore() {
        return handle.getLiveData(KEY_CURRENT_SCORE);
    }

    public MutableLiveData<Integer> getAnswer() {
        return handle.getLiveData(KEY_ANSWER);
    }

    void generator() {
        int LEVEL = 20;
        Random random = new Random();
        int x, y;
        x = random.nextInt(LEVEL) + 1;
        y = random.nextInt(LEVEL) + 1;
        if (x % 2 == 0) {
            getOpreator().setValue("+");
            if (x > y) {
                getAnswer().setValue(x);
                getLeftNumber().setValue(y);
                getRightNumber().setValue(x - y);
            } else {
                getAnswer().setValue(y);
                getLeftNumber().setValue(x);
                getRightNumber().setValue(y - x);
            }
        } else {
            getOpreator().setValue("-");
            if (x > y) {
                getAnswer().setValue(x - y);
                getLeftNumber().setValue(x);
                getRightNumber().setValue(y);
            } else {
                getAnswer().setValue(y - x);
                getLeftNumber().setValue(y);
                getRightNumber().setValue(x);
            }
        }
    }


    void save() {
        SharedPreferences shp = getApplication().getSharedPreferences(SAVE_SHP_DATA_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = shp.edit();
        editor.putInt(KEY_HIGH_SCORE, getHighScore().getValue());
        editor.apply();
    }


    void answerCorrect() {
        getCurrentScore().setValue(getCurrentScore().getValue() + 1);
        if (getCurrentScore().getValue() > getHighScore().getValue()) {
            getHighScore().setValue(getCurrentScore().getValue());
            win_flag = true;
        }
        generator();
    }

}

fragment_title.xml

<?xml version="1.0" encoding="utf-8"?>
<layout 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">

    <data>
        <variable
            name="data"
            type="com.example.calculationtest.MyViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".TitleFragment">

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.1" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.9" />

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/title_message"
            android:textAlignment="center"
            android:textSize="@dimen/big_font"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@+id/guideline2"
            app:layout_constraintHorizontal_bias="0.652"
            app:layout_constraintStart_toStartOf="@+id/guideline"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.201" />

        <ImageView
            android:id="@+id/imageView"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:contentDescription="@string/title_image_info"
            android:src="@drawable/titleimage"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintDimensionRatio="w,1:1"
            app:layout_constraintEnd_toStartOf="@+id/guideline2"
            app:layout_constraintStart_toStartOf="@+id/guideline"
            app:layout_constraintTop_toTopOf="parent" />

        <Button
            android:id="@+id/button"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/title_button_message"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="@+id/imageView"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="@+id/imageView"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.85" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{@string/high_score_message(data.highScore)}"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.875"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.116"
            tools:text="High Score:%d" />
    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

imageview所用图片是网上下载的
右上角的"high score :%d"，需要与viewmodel中的数据绑定
点击Enter，即可进入答题界面

TitleFragment.java

 @Override
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
         MyViewModel myViewModel;
         myViewModel = ViewModelProviders.of(requireActivity(), new SavedStateViewModelFactory(requireActivity())).get(MyViewModel.class);
         FragmentTitleBinding binding;
         binding = DataBindingUtil.inflate(inflater,R.layout.fragment_title,container,false);
         binding.setData(myViewModel);
         binding.setLifecycleOwner(requireActivity());
         binding.button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 NavController controller = Navigation.findNavController(v);
                 controller.navigate(R.id.action_titleFragment_to_questionFragment);
             }
         });
         return binding.getRoot();
         // Inflate the layout for this fragment
         //return inflater.inflate(R.layout.fragment_title, container, false);
     }

fragment_question.xml

<?xml version="1.0" encoding="utf-8"?>
<layout 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">

    <data>
        <variable
            name="data"
            type="com.example.calculationtest.MyViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".QuestionFragment">

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline9"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.85" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline8"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.45" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline7"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.37" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.1" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.9" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.15" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.25" />

        <TextView
            android:id="@+id/textView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:text="@{@string/current_score(data.currentScore)}"
            app:layout_constraintBottom_toTopOf="@+id/guideline5"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline5"
            tools:text="Score:5" />

        <TextView
            android:id="@+id/textView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{String.valueOf(safeUnbox(data.leftNumber))}"
            android:textSize="@dimen/huge_font"
            app:layout_constraintBottom_toBottomOf="@+id/textView5"
            app:layout_constraintEnd_toStartOf="@+id/textView5"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="@+id/guideline3"
            app:layout_constraintTop_toTopOf="@+id/textView5"
            tools:text="8" />

        <TextView
            android:id="@+id/textView5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{data.opreator}"
            android:textSize="@dimen/huge_font"
            app:layout_constraintBottom_toBottomOf="@+id/textView6"
            app:layout_constraintEnd_toStartOf="@+id/textView6"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/textView4"
            app:layout_constraintTop_toTopOf="@+id/textView6"
            tools:text="+" />

        <TextView
            android:id="@+id/textView6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{String.valueOf(safeUnbox(data.rightNumber))}"
            android:textSize="@dimen/huge_font"
            app:layout_constraintBottom_toBottomOf="@+id/textView7"
            app:layout_constraintEnd_toStartOf="@+id/textView7"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/textView5"
            app:layout_constraintTop_toTopOf="@+id/textView7"
            tools:text="9" />

        <TextView
            android:id="@+id/textView7"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/equal_symbol"
            android:textSize="@dimen/huge_font"
            app:layout_constraintBottom_toBottomOf="@+id/textView8"
            app:layout_constraintEnd_toStartOf="@+id/textView8"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/textView6"
            app:layout_constraintTop_toTopOf="@+id/textView8"
            tools:text="=" />

        <TextView
            android:id="@+id/textView8"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/question_mark"
            android:textSize="@dimen/huge_font"
            app:layout_constraintBottom_toTopOf="@+id/guideline6"
            app:layout_constraintEnd_toStartOf="@+id/guideline4"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/textView7"
            app:layout_constraintTop_toTopOf="@+id/guideline6"
            tools:text="\\?" />

        <TextView
            android:id="@+id/textView9"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/input_indicator"
            android:textSize="@dimen/mid_font"
            app:layout_constraintBottom_toTopOf="@+id/guideline7"
            app:layout_constraintEnd_toStartOf="@+id/guideline4"
            app:layout_constraintStart_toStartOf="@+id/guideline3"
            app:layout_constraintTop_toTopOf="@+id/guideline7" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline10"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.55" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline11"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.65" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline12"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.75" />

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button1"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toTopOf="@+id/guideline10"
            app:layout_constraintEnd_toStartOf="@+id/button2"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="@+id/guideline3"
            app:layout_constraintTop_toTopOf="@+id/guideline8" />

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button2"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button1"
            app:layout_constraintEnd_toStartOf="@+id/button3"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/button1"
            app:layout_constraintTop_toTopOf="@+id/button1" />

        <Button
            android:id="@+id/button3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button3"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button2"
            app:layout_constraintEnd_toStartOf="@+id/guideline4"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/button2"
            app:layout_constraintTop_toTopOf="@+id/button2" />

        <Button
            android:id="@+id/button4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button4"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toTopOf="@+id/guideline11"
            app:layout_constraintEnd_toStartOf="@+id/button5"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="@+id/guideline3"
            app:layout_constraintTop_toTopOf="@+id/guideline10" />

        <Button
            android:id="@+id/button6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button6"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button5"
            app:layout_constraintEnd_toStartOf="@+id/guideline4"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/button5"
            app:layout_constraintTop_toTopOf="@+id/button5"
            app:layout_constraintVertical_bias="0.0" />

        <Button
            android:id="@+id/button5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button5"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button4"
            app:layout_constraintEnd_toStartOf="@+id/button6"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/button4"
            app:layout_constraintTop_toTopOf="@+id/button4"
            app:layout_constraintVertical_bias="0.0" />

        <Button
            android:id="@+id/button7"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button7"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toTopOf="@+id/guideline12"
            app:layout_constraintEnd_toStartOf="@+id/button8"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="@+id/guideline3"
            app:layout_constraintTop_toTopOf="@+id/guideline11" />

        <Button
            android:id="@+id/button8"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button8"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button7"
            app:layout_constraintEnd_toStartOf="@+id/button9"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/button7"
            app:layout_constraintTop_toTopOf="@+id/button7" />

        <Button
            android:id="@+id/button9"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button9"
            android:textSize="@dimen/button_font"
            app:layout_constraintBottom_toBottomOf="@+id/button8"
            app:layout_constraintEnd_toStartOf="@+id/guideline4"以上是关于Android学习进度四的主要内容，如果未能解决你的问题，请参考以下文章 
 验证码逆向专栏某验四代文字点选验证码逆向分析
 Android学习进度四
 实验四代码评审
 如何在家庭活动android上显示进度对话框？
 更改片段时显示 ProgressBar - Android
 片段隐藏在Android中不起作用