Android开发-Activity和Fragment传值相关(Activity传值给Fragment)

一时失言乱红尘 2024-05-03 14:38 78阅读 0赞

简介：

Activity经常需要向Fragment进行数据传递,推荐使用fragment.newInstance的方式进行数据传递，以保证界面切换的时候数据不会丢失。

参考阅读：Android开发-Fragment和Activity传值相关(Fragment传值给Activity)

步骤一：MainActivity.java文件

package com.huwan.activity2fragmentvaluedemo2;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

public class MainActivity extends AppCompatActivity \{

// 1.定义了几个字符串

private String aaaa = "字母a值";

private String bbbb = "字母b值";

private String cccc = "字母c值";

@Override

protected void onCreate(Bundle savedInstanceState) \{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity\_main);

// 4.点击进行fragment切换

Button btn1;

Button btn2;

Button btn3;

btn1 = findViewById(R.id.btn1);

btn1.setOnClickListener(new View.OnClickListener() \{

@Override

public void onClick(View v) \{

getSupportFragmentManager().beginTransaction().replace(R.id.content\_frame, Fragment1.newInstance(aaaa, bbbb)).commit();

\});

btn2 = findViewById(R.id.btn2);

btn2.setOnClickListener(new View.OnClickListener() \{

@Override

public void onClick(View v) \{

getSupportFragmentManager().beginTransaction().replace(R.id.content\_frame, Fragment1.newInstance(bbbb, cccc)).commit();

\});

btn3 = findViewById(R.id.btn3);

btn3.setOnClickListener(new View.OnClickListener() \{

@Override

public void onClick(View v) \{

getSupportFragmentManager().beginTransaction().replace(R.id.content\_frame, Fragment1.newInstance(aaaa, cccc)).commit();

\});

// 2.activity的数据可能是传递或者获取的，所以一定要进行判断

if (savedInstanceState != null) \{

aaaa = savedInstanceState.getString("字母a值");

bbbb = savedInstanceState.getString("字母b值");

cccc = savedInstanceState.getString("字母c值");

// 3.防止数据丢失，一定要进行保存

@Override

protected void onSaveInstanceState(Bundle outState) \{

super.onSaveInstanceState(outState);

outState.putString("字母a值", aaaa);

outState.putString("字母b值", bbbb);

outState.putString("字母c值", cccc);

步骤二：Fragment1.java文件

package com.huwan.activity2fragmentvaluedemo2;

import android.app.Activity;

import android.support.v4.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.TextView;

public class Fragment1 extends Fragment \{

//5.获取传递过来的值，并保存在bundle中

String zhi1;

String zhi2;

public static Fragment1 newInstance(String zhi1,String zhi2) \{

Fragment1 newFragment = new Fragment1();

Bundle bundle = new Bundle();

bundle.putString("zhi1", zhi1);

bundle.putString("zhi2", zhi2);

newFragment.setArguments(bundle);

return newFragment;

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) \{

View view = inflater.inflate(R.layout.fragment1, container, false);

//6.将保存的值取出，进行展示

Bundle args = getArguments();

if (args != null)\{

zhi1 = args.getString("zhi1");

zhi2 = args.getString("zhi2");

TextView text1 = view.findViewById(R.id.text1);

text1.setText(zhi1);

TextView text2 = view.findViewById(R.id.text2);

text2.setText(zhi2);

return view;

步骤三：其它相关文件

activity\_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout\_width="match\_parent"

android:layout\_height="match\_parent"

android:orientation="vertical">

<Button

android:id="@+id/btn1"

android:layout\_width="wrap\_content"

android:layout\_height="wrap\_content"

android:textColor="@color/colorAccent"

android:textSize="20dp"

android:text="切换一" />

<Button

android:id="@+id/btn2"

android:layout\_width="wrap\_content"

android:layout\_height="wrap\_content"

android:textColor="@color/colorAccent"

android:textSize="20dp"

android:text="切换二" />

<Button

android:id="@+id/btn3"

android:layout\_width="wrap\_content"

android:layout\_height="wrap\_content"

android:textColor="@color/colorAccent"

android:textSize="20dp"

android:text="切换三" />

<FrameLayout

android:id="@+id/content\_frame"

android:layout\_width="match\_parent"

android:layout\_height="match\_parent"

android:background="\#ff0000"

android:fitsSystemWindows="true" />

</LinearLayout>

\----------------------------------------------------------------

fragment1.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout\_width="match\_parent"

android:layout\_height="match\_parent"

android:orientation="vertical"

android:background="@color/colorAccent">

<TextView

android:id="@+id/text1"

android:layout\_width="wrap\_content"

android:layout\_height="wrap\_content"

android:textSize="20dp"

android:text="值一" />

<TextView

android:id="@+id/text2"

android:layout\_width="wrap\_content"

android:layout\_height="wrap\_content"

android:textSize="20dp"

android:text="值二"/>

</LinearLayout>

Demo样例下载：

[http://www.huwan.xin/Source/AppPackage/ZIP/Android/ Activity2FragmentValueDemo2.rar][http_www.huwan.xin_Source_AppPackage_ZIP_Android_ Activity2FragmentValueDemo2.rar]

更多内容请访问：[www.huwan.xin][]

[http_www.huwan.xin_Source_AppPackage_ZIP_Android_ Activity2FragmentValueDemo2.rar]: http://www.huwan.xin/Source/AppPackage/ZIP/Android/%20Activity2FragmentValueDemo2.rar
[www.huwan.xin]: http://www.huwan.xin