Android中系統設定參數改變監聽（以時間同步為例）

 

import java.text.SimpleDateFormat;import java.util.Date;import android.app.Activity;import android.database.ContentObserver;import android.os.Bundle;import android.os.Handler;import android.provider.Settings;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;public class MainActivity extends Activity {    private static final String TAG = "MainActivity";    private static final int ON = 1;    private static final int OFF = 0;    private Button mbtnGetStatus;    private Button mbtnAutoTime;    private Button mbtnAutoTimeListen;    private TextView mtvInfo;    /**     * 是否開啟時間同步監聽     */    private boolean isListening = false;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        mtvInfo = (TextView) findViewById(R.id.multiAutoCompleteTextView1);        mtvInfo.setText("");        mbtnGetStatus = (Button) findViewById(R.id.button1);        mbtnGetStatus.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                int nAutoTimeStatus = Settings.System.getInt(                        getContentResolver(), Settings.System.AUTO_TIME, OFF);                OutPrintLog("目前時間同步狀態：" + nAutoTimeStatus);            }        });        mbtnAutoTime = (Button) findViewById(R.id.button2);        mbtnAutoTime.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                int nAutoTimeStatus = Settings.System.getInt(                        getContentResolver(), Settings.System.AUTO_TIME, OFF);                Settings.System.putInt(getContentResolver(),                        Settings.System.AUTO_TIME, nAutoTimeStatus == OFF ? ON                                : OFF);                Refresh();            }        });        mbtnAutoTimeListen = (Button) findViewById(R.id.button3);        mbtnAutoTimeListen.setOnClickListener(new OnClickListener() {            private ContentObserver mAutoTimeObserver = new ContentObserver(                    new Handler()) {                @Override                public void onChange(boolean selfChange) {                    Log.i(TAG, "Auto time state changed");                    int nAutoTimeStatus = Settings.System.getInt(                            getContentResolver(), Settings.System.AUTO_TIME,                            OFF);                    OutPrintLog("目前時間同步狀態：" + nAutoTimeStatus);                }            };            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                if (!isListening) {                    getApplication()                            .getContentResolver()                            .registerContentObserver(                                    Settings.System                                            .getUriFor(Settings.System.AUTO_TIME),                                    true, mAutoTimeObserver);                } else {                    getApplicationContext().getContentResolver()                            .unregisterContentObserver(this.mAutoTimeObserver);                }                isListening = !isListening;                Refresh();            }        });        Refresh();    }    private void Refresh() {        int nAutoTimeStatus = Settings.System.getInt(getContentResolver(),                Settings.System.AUTO_TIME, OFF);        mbtnAutoTime                .setText(nAutoTimeStatus == OFF ? R.string.app_autotime_start                        : R.string.app_autotime_end);        mbtnAutoTimeListen                .setText(isListening ? R.string.app_autotimelisten_end                        : R.string.app_autotimelisten_start);    }    private void OutPrintLog(CharSequence text) {        mtvInfo.setText((mtvInfo.getText()).toString()                + new SimpleDateFormat("\n mm:ss").format(new Date())                + text.toString());    }