// 设置为无标题栏
requestWindowFeature(Window.FEATURE_NO_TITLE);
// 设置为全屏模式
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); 

//获取屏幕的高度和宽度用到WindowManager这个类
WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);

int width = wm.getDefaultDisplay().getWidth();
int height = wm.getDefaultDisplay().getHeight();

TelephonyManager tm = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);

String imei = tm.getDeviceId();//移动设备国际辨识码
String imsi = tm.getSubscriberId();//国际移动用户识别码
String tel = tm.getLine1Number();//电话号码

String model =  android.os.Build.MODEL;//手机型号
String sdk = android.os.Build.VERSION.SDK;//SDK版本
String release = android.os.Build.VERSION.RELEASE;//系统版本

//根据IMSI号码识别移动供应商
public String getProvidersName(String IMSI) {
    String ProvidersName = null;
    // IMSI号前面3位460是国家，紧接着后面2位00 02是中国移动，01是中国联通，03是中国电信。
    if (IMSI.startsWith("46000") || IMSI.startsWith("46002")) {
        ProvidersName = "中国移动";
    } else if (IMSI.startsWith("46001")) {
        ProvidersName = "中国联通";
    } else if (IMSI.startsWith("46003")) {
        ProvidersName = "中国电信";
    }
    return ProvidersName;
}

public void showToast(String text){
    Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
}

//把一个字符串写进文件
public void writeFile(String str,String path){
    File file;
    FileOutputStream out;
    try{
        //创建文件
        file = new File(path);
        file.createNewFile();
        //打开文件file的输出流
        out = new FileOutputStream(file);
        //将字符串转换成byte数组写入文件
        out.write(str.getBytes());
        out.close();
    }catch(IOException e){

    }
}

//把文件内容读出到字符串
public String getFileInfo(String path){
    File file;
    String str = "";
    FileInputStream in;
    try{
        //打开文件的inputStream
        file  new File(path);
        in = new FileInputStream(file);
        //将文件内容读入byte数组
        int length = (int)file.length();
        byte [] temp = new byte[length];
        in.read(temp,0,length);
        str = EncodingUtils.getString(temp, "utf-8");
        in.close();
    }catch(IOException e){

    }
    return str;
}

//调出系统安装应用
String fileName = Environment.getExternalStorageDirectory() + apkName;
Uri uri = Uri.fromFile(new File(fileName));
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(uri, "application/vnd.android.package-archive");
this.startActivity(intent);

//调出系统卸载应用
Uri packageURI = Uri.parse("package: your.app.id");
Intent intent = new Intent(Intent.ACTION_DELETE,packageURI);
startActivity(intent);

//第一步，定义一个变量，用于标识是否退出

boolean isExit;

//第二步，重写Activity中onKeyDown方法

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        exit();
        return false;
    } else {
        return super.onKeyDown(keyCode, event);
    }
}

//第三步，写一个退出方法
public void exit(){
    if (!isExit) {
        isExit = true;
        Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show();
        mHandler.sendEmptyMessageDelayed(0, 2000);
    } else {
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);
        startActivity(intent);
        System.exit(0);
    }
}

//第四步，根据exit()方法中的的消息，写一个Handler
Handler mHandler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
        // TODO Auto-generated method stub
        super.handleMessage(msg);
        isExit = false;
    }

};