Android Them+SharedPreferences 修改程序全部view字體顏色、大小和頁面背景

有這麼一個需求，能夠對頁面的樣式進行選擇，而後根據選擇改變程序全部字體顏色和頁面背景。同時下一次啓動程序，當前設置依然有效。

根據需求，咱們須要一種快速，方便，有效的方式來實現需求，而後能夠經過Android Them + SharedPreferences 來實現需求。Them用於存放設置的每一種樣式，並應用於程序中，SharedPreferences用於記住程序當前的樣式，根據SharedPreferences的內容來設置程序的樣式，實現下次啓動可以oncreat當前的樣式設置。

這裏的Them比較簡單，只是定義了字體顏色和頁面背景顏色。在res/values/styles.xml 文件中增長Them主題

    <style name="FirstThem">
        <item name="android:textColor">@color/FirstThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/FirstThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>
    
    <style name="SecondThem">
        <item name="android:textColor">@color/SecondThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/SecondThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>
    
    <style name="ThirdThem">
        <item name="android:textColor">@color/ThirdThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/ThirdThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>

而後在MainActivity.java中建立SharedPreferences來記錄樣式的狀態

    private void SharePreference() {
        sharePrefences=this.getSharedPreferences("config",Context.MODE_WORLD_READABLE
                | Context.MODE_WORLD_WRITEABLE);
        editor=sharePrefences.edit();
        boolean isThem = sharePrefences.getBoolean("isThem", false);
        int Them = sharePrefences.getInt("Them",0);//config不存在時返回0
        if(isThem){
            if(Them==1){
                setTheme(R.style.FirstThem);
            }else if(Them==2){
                setTheme(R.style.SecondThem);
            }else if(Them==3){
                setTheme(R.style.ThirdThem);
            }
        }else{//sharePrefences不存在是使用默認主題
            setTheme(R.style.FirstThem);
        }
        }

有兩個比較值得注意的地方是：

一、設置主題時，setTheme(R.style.FirstThem);必定要放在setContentView(R.layout.activity_main);前，不然無效。

setTheme(R.style.FirstThem);
setContentView(R.layout.activity_main);

二、要全部頁面的字體顏色和背景可以根據Them去改變，那麼佈局文件中的目標控件都不能設置android:textcolor,以及android:background.不然控件的android:textcolor，android:background屬性會將Them的設置覆蓋。

 

下面是一個demo的完整代碼：

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/FirstThem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="樣式一"
    />

<Button 
    android:id="@+id/SecondThem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="樣式二"
    />

<Button 
    android:id="@+id/ThirdThem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="樣式三"
    />

<TextView 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="50dp"
    android:textSize="30sp"
    android:text="ABCDEFG"
    />

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity implements OnClickListener {
    private Button FirstThemButton;
    private Button SecondThemButton;
    private Button ThirdThemButton;
    private SharedPreferences sharePrefences;
    private Editor editor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SharePreference();
        setContentView(R.layout.activity_main);
        InitView();
        FirstThemButton=(Button) findViewById(R.id.FirstThem);
        SecondThemButton=(Button) findViewById(R.id.SecondThem);
        SecondThemButton=(Button) findViewById(R.id.ThirdThem);
    }

    private void SharePreference() {
        sharePrefences=this.getSharedPreferences("config",Context.MODE_WORLD_READABLE
                | Context.MODE_WORLD_WRITEABLE);
        editor=sharePrefences.edit();
        boolean isThem = sharePrefences.getBoolean("isThem", false);
        int Them = sharePrefences.getInt("Them",0);//config不存在時返回0
        if(isThem){
            if(Them==1){
                setTheme(R.style.FirstThem);
            }else if(Them==2){
                setTheme(R.style.SecondThem);
            }else if(Them==3){
                setTheme(R.style.ThirdThem);
            }
        }else{//sharePrefences不存在是使用默認主題
            setTheme(R.style.FirstThem);
        }
        }

    private void InitView() {
        FirstThemButton=(Button) findViewById(R.id.FirstThem);
        SecondThemButton=(Button) findViewById(R.id.SecondThem);
        ThirdThemButton=(Button) findViewById(R.id.ThirdThem);
        FirstThemButton.setOnClickListener(this);
        SecondThemButton.setOnClickListener(this);
        ThirdThemButton.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.FirstThem:
            editor.putBoolean("isThem", true);
            editor.putInt("Them", 1);
            editor.commit();
            Intent intent1=new Intent(this,MainActivity.class);
            startActivity(intent1);
            break;
        case R.id.SecondThem:
            editor.putBoolean("isThem", true);
            editor.putInt("Them",2);
            editor.commit();
            Intent intent2=new Intent(this,MainActivity.class);
            startActivity(intent2);
            break;
        case R.id.ThirdThem:
            editor.putBoolean("isThem", true);
            editor.putInt("Them", 3);
            editor.commit();
            Intent intent3=new Intent(this,MainActivity.class);
            startActivity(intent3);
            break;
        default:
            break;
        }
        
    }
    
    
}

styles.xml

<resources>

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    </style>
    
    <style name="FirstThem">
        <item name="android:textColor">@color/FirstThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/FirstThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>
    
    <style name="SecondThem">
        <item name="android:textColor">@color/SecondThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/SecondThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>
    
    <style name="ThirdThem">
        <item name="android:textColor">@color/ThirdThemTextColor</item> <!-- 字體顏色  -->
        <item name="android:windowBackground">@color/ThirdThemBackgroundColor</item> <!-- 窗口背景 -->
    </style>

</resources>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="FirstThemTextColor">#000000</color>
    <color name="FirstThemBackgroundColor">#FFFFFF</color>
    <color name="SecondThemTextColor">#AAAAAA</color>
    <color name="SecondThemBackgroundColor">#EEBBEE</color>
    <color name="ThirdThemTextColor">#CCCCCC</color>
    <color name="ThirdThemBackgroundColor">#AAAADD</color>
</resources>