Android事件处理之三 响应的系统设置的事件

应用程序随系统设置进行调整，如屏幕方向、判断系统方向的导航设备。有时也需让应用监听系统的动态配置

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3.4.1 Configuration 简介

调用如下方法获取系统的Configuration对象：

Configuration cfg = getResource().getConfiguration();

获得系统Configuration对象后，有如下常用属性配置：

public float fontScale	获取当前用户设置的字体缩放因子
public int keyboard	获取当前设置所关联的键盘类型 KEYBOARD_NOKEYS KEYBOARD_QWERTY（普通电脑键盘） KEYBOARD_12KEY（只有12个键的小键盘）
public int keyboardHidden	返回一个boolean值标识当前键盘是否可用（软键盘也在检测范围之内）
public Locale locale	获取当前的Locale
public int mcc	获取移动信号的国家码
public int mnc	网络码
public int navigation	判断系统上方向导航的类型 NAVIGATION_NONAV NAVIGATION_DPAD NAVIGATION_TRACKBALL NAVIGATION_WHEEL
public int orientation	获取屏幕方向 ORIENTATION_LANDSCAPE ORIENTATION_PORTRAIT ORIENTATION_SQUARE
public int touchscreen	获取系统触摸屏方式 TOUCHSCREEN_NOTOUCH TOUCHSCREEN_STYLUS TOUCHSCREEN_FINGER

获取手机信息示例代码：

xml

    <EditText
        android:id="@+id/ori"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:editable="false"
        android:cursorVisible="false"

        android:hint="display screen orientation" />

java代码：

public class MainActivity extends ActionBarActivity {

EditText ori;
EditText navigation;
EditText touch;
EditText mnc;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ori = (EditText) findViewById(R.id.ori);
        navigation = (EditText) findViewById(R.id.navigation);
        touch = (EditText) findViewById(R.id.touch);
        mnc = (EditText) findViewById(R.id.mnc);
        Button bn = (Button) findViewById(R.id.bn);
        bn.setOnClickListener( new OnClickListener()
        {
        @Override
        public void onClick(View source)
        {
        Configuration cfg = getResources().getConfiguration();
        String screen = cfg.orientation ==
        Configuration.ORIENTATION_LANDSCAPE?
        "LANDSCAPE SCREEN":"PORTRAINT SCREEN";
        String mncCode = cfg.mnc + "";
        String naviName = cfg.orientation ==
        Configuration.NAVIGATION_NONAV?
        "no navigation control":
        cfg.orientation ==
        Configuration.NAVIGATION_WHEEL?
        "滚轮控制":
                cfg.orientation ==
                Configuration.NAVIGATION_DPAD?
                "no orientation control":
                "DPAD control orientation";
        navigation.setText(naviName);
        String touchName = cfg.touchscreen ==
        Configuration.TOUCHSCREEN_NOTOUCH?
        "no touch screen":"support bar";
        ori.setText(screen);
        mnc.setText(mncCode);
       
        }
        });

    }

}

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3.4.2 重写onConfigurationChanged响应系统设置更改

监听系统设置的更改——重写Activity的onConfigurationChanged(Configuration newConfig)方法，该方法是一个基于回调的事件处理方法：当系统设置更改时，该方法会自动触发。

为了在程序中动态地更改系统设置，可以调用Activity的setRequestedOrientation(int)方法来修改屏幕方向

示例代码：

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bn = (Button) findViewById(R.id.bn);
        bn.setOnClickListener(new OnClickListener()
        {
        @Override
        public void onClick(View source)
        {
        Configuration config =getResources().getConfiguration();
        if(config.orientation == Configuration.ORIENTATION_LANDSCAPE)
        {
        MainActivity.this.setRequestedOrientation(
        ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        }
        if(config.orientation == Configuration.ORIENTATION_PORTRAIT)
        {
        MainActivity.this.setRequestedOrientation(
        ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        }
        }
        });

    }

若想监听系统设置关于屏幕更改的设置，需重写onConfigurationChanged（Configuration newConfig）方法，另外，还需更改配置文件内设置：

        <activity

            android:configChanges="orientation"

main.java内重写代码：

 @Override

    public void onConfigurationChanged(Configuration newConfig)
    {
    super.onConfigurationChanged(newConfig);
    String screen = newConfig.orientation ==
    Configuration.ORIENTATION_LANDSCAPE?
    "landscape screen":"portrait screen";
    Toast.makeText(this, "screen orientation change to " + screen, Toast.LENGTH_LONG).show();
    }