android app中如何获取电源锁保持屏幕常亮

android app中如何获取电源锁保持屏幕常亮

protected void screen_on() {

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

}

protected void screen_off() {

getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

}

Java Timer

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
    public static int x;
    public static void main(String[] args) throws Exception {
        x = 30 * 60 + 9;
        System.out.println(x);
        while(x != 0){
            x = x -1;
            show();
        }    
    }
   
    public static void show(){
        int hh = x /60;
        int ss = x - hh * 60;
        int hht1 = hh % 100 /10;
        int hht2 = hh % 10;
        int sst1 = ss % 100 /10;
        int sst2 = ss % 10;
        System.out.println("--------------");
        System.out.print(hht1);
        System.out.print(hht2);
        System.out.print(sst1);
        System.out.println(sst2);
        System.out.println("--------------");
    }
}

https://paiza.io/projects/FJ_pxjUT07pv51Ab7TWA4w

android 屏幕旋转

android 屏幕旋转

<activity android:name=".MainActivity"
android:screenOrientation="portrait">

纵向方向（显示的高度大于宽度）。

https://developer.android.com/guide/topics/manifest/activity-element.html

android Bitmap to File

android Bitmap to File


    case REQUEST_IMAGE_CAPTURE:
        File f = getFilesDir();
        Bitmap bit = data.getExtras().getParcelable("data");
        ImageView imageView = (ImageView) findViewById(R.id.bit);
        imageView.setImageBitmap(bit);

        try {
            FileOutputStream fileOutputStream = new FileOutputStream(f.getPath() + "/xxx.jpg");
            bit.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream);
            fileOutputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        break;