Question

我正在尝试实施一个应用程序，在用户按下按钮后每5秒继续拍照。这是我的完整代码：

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.os.CountDownTimer;
import android.os.Environment;
import android.view.SurfaceView;
import android.view.View;
import android.widget.TextView;

public class MyAutoCamera extends Activity {
    private Camera camera; // camera object
    private TextView textTimeLeft; // time left field
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textTimeLeft=(TextView)findViewById(R.id.textTimeLeft); //make time left object
        camera = Camera.open();
        SurfaceView view = new SurfaceView(this);

        try {
            camera.setPreviewDisplay(view.getHolder()); // feed dummy surface to surface
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        camera.startPreview(); 
    }


    Camera.PictureCallback jpegCallBack=new Camera.PictureCallback() {      
        public void onPictureTaken(byte[] data, Camera camera) {
            // set file destination and file name
            String path = Environment.getExternalStorageDirectory().getAbsolutePath();
            path += "/AutoPictures/myPicture.jpg";//***
            File file = new File(path);//***

            //File destination=new File(Environment.getExternalStorageDirectory(),"myPicture.jpg");
            try {
                Bitmap userImage = BitmapFactory.decodeByteArray(data, 0, data.length);
                // set file out stream
                FileOutputStream out = new FileOutputStream(file);//**
                //FileOutputStream out = new FileOutputStream(destination);
                // set compress format quality and stream
                userImage.compress(Bitmap.CompressFormat.JPEG, 90, out);        

            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    };

    public void startTimer(View v){

        // 5000ms=5s at intervals of 1000ms=1s so that means it lasts 5 seconds
        new CountDownTimer(5000,1000){

            @Override
            public void onFinish() {
                // count finished
                textTimeLeft.setText("Picture Taken");
                camera.takePicture(null, null, null, jpegCallBack);
            }

            @Override
            public void onTick(long millisUntilFinished) {
                // every time 1 second passes
                textTimeLeft.setText("Seconds Left: "+millisUntilFinished/1000);
            }

        }.start();
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.my_auto_camera, menu);
        return true;
    }

}

main.xml中：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MyAutoCamera" >


    <Button 
        android:id ="@+id/buttonStartTimer"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"
        android:text= "Start Timer"
        android:onClick="startTimer"/>

    <TextView
        android:id ="@+id/textTimeLeft"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="" />

</LinearLayout>

和权限：

<uses-feature android:name="android.hardware.camera" />
    <uses-feature
        android:name="android.hardware.camera.front"
        android:required="false" />

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

我的问题是：

在应用程序显示拍摄照片后，我无法在存储空间中找到该照片。我在我的设备上创建了一个名为AutoPictures的文件夹。
如何修改上面的代码，每隔5秒继续拍照，而不只是一张照片？

非常感谢任何帮助。

Answer 1

将文件添加到文件系统后，为了使其在连接到存储时可见，请运行以下代码：

Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri uri = Uri.fromFile(exportFile);
intent.setData(uri);
ctx.sendBroadcast(intent);

至于继续拍照，还有很多方法可以做，Handler，Timer，ScheduledThreadPoolExecutor，AsyncTask等...... http://developer.android.com/reference/java/util/Timer.html http://developer.android.com/reference/android/os/AsyncTask.html

你应该生成文件名（基于时间？），这样他们就不会超过写作。

基于计时器的Android Camera App

1 个答案: