Android如何通過(guò)ViewModel保存數(shù)據(jù)實(shí)現(xiàn)多頁(yè)面的數(shù)據(jù)共享功能

小編給大家分享一下Android如何通過(guò)ViewModel保存數(shù)據(jù)實(shí)現(xiàn)多頁(yè)面的數(shù)據(jù)共享功能，相信大部分人都還不怎么了解，因此分享這篇文章給大家參考一下，希望大家閱讀完這篇文章后大有收獲，下面讓我們一起去了解一下吧！

在海州等地區(qū)，都構(gòu)建了全面的區(qū)域性戰(zhàn)略布局，加強(qiáng)發(fā)展的系統(tǒng)性、市場(chǎng)前瞻性、產(chǎn)品創(chuàng)新能力，以專注、極致的服務(wù)理念，為客戶提供成都網(wǎng)站設(shè)計(jì)、成都網(wǎng)站制作、外貿(mào)網(wǎng)站建設(shè) 網(wǎng)站設(shè)計(jì)制作按需定制開(kāi)發(fā),公司網(wǎng)站建設(shè),企業(yè)網(wǎng)站建設(shè),品牌網(wǎng)站制作,營(yíng)銷(xiāo)型網(wǎng)站建設(shè),外貿(mào)網(wǎng)站建設(shè),海州網(wǎng)站建設(shè)費(fèi)用合理。

通過(guò)ViewModel實(shí)現(xiàn)的數(shù)據(jù)共享符合Android的MVC設(shè)計(jì)模式，將數(shù)據(jù)獨(dú)立出來(lái)

實(shí)現(xiàn)的Demo

1、主頁(yè)面通過(guò)SeekBar 來(lái)改變數(shù)字的值

2、點(diǎn)擊進(jìn)入就進(jìn)入第二個(gè)界面，但是數(shù)據(jù)還是共享的

3、隨便加兩個(gè)數(shù)字上去，再次切換

4、發(fā)現(xiàn)數(shù)據(jù)還是共享的

下面是具體實(shí)現(xiàn)步驟：

1、建立兩個(gè)Fragment（使用了Binding 和 Navigation）

一點(diǎn)要添加Binding 和 Navigation 不然做不了

2、建立一個(gè)繼承于ViewModel的類

3、分別在兩個(gè)Fragment的代碼中使用繼承于ViewModel的那個(gè)類，就可以實(shí)現(xiàn)數(shù)據(jù)共享

下面是具體代碼：

1、繼承于ViewModel的類

package com.example.naviation01;import androidx.lifecycle.MutableLiveData;import androidx.lifecycle.ViewModel;public class MyViewMode extends ViewModel { private MutableLiveData<Integer> number; public MutableLiveData<Integer> getNumber(){ if(this.number == null){ this.number = new MutableLiveData<>(); this.number.setValue(0); } return this.number; } public void add(int x){ this.number.setValue(this.number.getValue()+x); if(this.number.getValue() < 0){ this.number.setValue(0); } }}

2、Fragment 主頁(yè)

package com.example.naviation01;import android.os.Bundle;import androidx.databinding.DataBindingUtil;import androidx.fragment.app.Fragment;import androidx.fragment.app.FragmentController;import androidx.lifecycle.ViewModel;import androidx.lifecycle.ViewModelProvider;import androidx.lifecycle.ViewModelProviders;import androidx.navigation.NavController;import androidx.navigation.Navigation;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.SeekBar;import com.example.naviation01.databinding.FragmentHomeBinding;/** * A simple {@link Fragment} subclass. */public class HomeFragment extends Fragment { public HomeFragment() { // Required empty public constructor } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment final MyViewMode myViewMode; myViewMode = ViewModelProviders.of(getActivity()).get(MyViewMode.class); FragmentHomeBinding binding; binding = DataBindingUtil.inflate(inflater,R.layout.fragment_home,container,false); binding.setData(myViewMode); binding.setLifecycleOwner(getActivity()); binding.seekBar.setProgress(myViewMode.getNumber().getValue()); binding.seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() { @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { myViewMode.getNumber().setValue(progress); } @Override public void onStartTrackingTouch(SeekBar seekBar) { } @Override public void onStopTrackingTouch(SeekBar seekBar) { } }); binding.button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { NavController controller = Navigation.findNavController(v); controller.navigate(R.id.action_homeFragment_to_detailFragment); } }); return binding.getRoot(); //return inflater.inflate(R.layout.fragment_home, container, false); }}

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.naviation01.MyViewMode" /> </data> <FrameLayout android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".HomeFragment"> <androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="8dp" android:layout_marginEnd="8dp" android:layout_marginBottom="8dp" android:text="@{String.valueOf(data.number)}" android:textSize="30sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.255" /> <SeekBar android:id="@+id/seekBar" 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" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.456" /> <Button android:id="@+id/button" 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/function01" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.498" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.679" /> </androidx.constraintlayout.widget.ConstraintLayout> </FrameLayout></layout>

3、Fragment 副頁(yè)

package com.example.naviation01;import android.os.Bundle;import androidx.databinding.DataBindingUtil;import androidx.fragment.app.Fragment;import androidx.lifecycle.ViewModelProviders;import androidx.navigation.NavController;import androidx.navigation.Navigation;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import com.example.naviation01.databinding.FragmentDetailBinding;/** * A simple {@link Fragment} subclass. */public class DetailFragment extends Fragment { public DetailFragment() { // Required empty public constructor } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment MyViewMode myViewMode; myViewMode = ViewModelProviders.of(getActivity()).get(MyViewMode.class); FragmentDetailBinding binding; binding = DataBindingUtil.inflate(inflater,R.layout.fragment_detail,container,false); binding.setDate(myViewMode); binding.setLifecycleOwner(getActivity()); binding.button4.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { NavController controller = Navigation.findNavController(v); controller.navigate(R.id.action_detailFragment_to_homeFragment); } }); return binding.getRoot(); //return inflater.inflate(R.layout.fragment_detail, container, false); }}

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="date" type="com.example.naviation01.MyViewMode" /> </data> <FrameLayout android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".DetailFragment"> <androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/textView3" android:layout_width="131dp" android:layout_height="55dp" android:layout_marginStart="8dp" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:layout_marginBottom="8dp" android:text="@{String.valueOf(date.number)}" android:textSize="30sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.23" /> <Button android:id="@+id/button2" 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/function02" android:onClick="@{()->date.add(1)}" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.104" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.499" /> <Button android:id="@+id/button3" 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/function03" android:onClick="@{()->date.add(-1)}" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.899" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.499" /> <Button android:id="@+id/button4" 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/function04" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.498" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.664" /> </androidx.constraintlayout.widget.ConstraintLayout> </FrameLayout></layout>

4、xml Main_Activity

<?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"> <fragment android:id="@+id/fragment" android:name="androidx.navigation.fragment.NavHostFragment" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:layout_marginBottom="8dp" app:defaultNavHost="true" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:navGraph="@navigation/nav_graph" /></androidx.constraintlayout.widget.ConstraintLayout>

以上是“Android如何通過(guò)ViewModel保存數(shù)據(jù)實(shí)現(xiàn)多頁(yè)面的數(shù)據(jù)共享功能”這篇文章的所有內(nèi)容，感謝各位的閱讀！相信大家都有了一定的了解，希望分享的內(nèi)容對(duì)大家有所幫助，如果還想學(xué)習(xí)更多知識(shí)，歡迎關(guān)注創(chuàng)新互聯(lián)行業(yè)資訊頻道！

本文名稱：Android如何通過(guò)ViewModel保存數(shù)據(jù)實(shí)現(xiàn)多頁(yè)面的數(shù)據(jù)共享功能
網(wǎng)站地址：http://muchs.cn/article20/ipghjo.html

成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián)，為您提供網(wǎng)站排名、品牌網(wǎng)站制作、小程序開(kāi)發(fā)、動(dòng)態(tài)網(wǎng)站、搜索引擎優(yōu)化、App開(kāi)發(fā)

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請(qǐng)盡快告知，我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng)，如需處理請(qǐng)聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時(shí)需注明來(lái)源：創(chuàng)新互聯(lián)

猜你還喜歡下面的內(nèi)容