代碼與範例:
首先需要在Manifest檔案中添加以下內容:
以使程式擷取網路攝影機使用以及自動對焦功能的使用許可權。
CameraTestActivity.java
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;
public class CameraTestActivity extends Activity {
@Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
requestWindowFeature(Window.FEATURE_NO_TITLE);// 設定橫屏模式以及全螢幕模式
setContentView(new CameraView(this)); //設定View
}
}
CameraView.java
import java.io.FileOutputStream;
import android.content.Context;
import android.hardware.Camera;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraView extends SurfaceView implements SurfaceHolder.Callback, Camera.PictureCallback {
private SurfaceHolder holder;
private Camera camera;
private boolean af;
public CameraView(Context context) {//建構函式
super(context);
holder = getHolder();//產生Surface Holder
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//指定Push Buffer
}
public void surfaceCreated(SurfaceHolder holder) {//Surface建置事件的處理
try {
camera = Camera.open();//網路攝影機的初始化
camera.setPreviewDisplay(holder);
} catch (Exception e) {
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {//Surface改變事件的處理
Camera.Parameters parameters = camera.getParameters();
parameters.setPreviewSize(width, height);
camera.setParameters(parameters);//設定參數
camera.startPreview();//開始預覽
}
public void surfaceDestroyed(SurfaceHolder holder) {//Surface銷毀時的處理
camera.setPreviewCallback(null);
camera.stopPreview();
camera.release();
camera =null;
}
@Override
public boolean onTouchEvent(MotionEvent event) {//螢幕觸摸事件
if (event.getAction() == MotionEvent.ACTION_DOWN) {//按下時自動對焦
camera.autoFocus(null);
af =true;
}
if (event.getAction() == MotionEvent.ACTION_UP && af ==true) {//放開後拍照
camera.takePicture(null, null, this);
af =false;
}
returntrue;
}
public void onPictureTaken(byte[] data, Camera camera) {//拍攝完成後儲存照片
try {
String path = Environment.getExternalStorageDirectory() +"/test.jpg";
data2file(data, path);
} catch (Exception e) {
}
camera.startPreview();
}
private void data2file(byte[] w, String fileName) throws Exception {//將位元據轉換為檔案的函數
FileOutputStream out =null;
try {
out =new FileOutputStream(fileName);
out.write(w);
out.close();
} catch (Exception e) {
if (out !=null)
out.close();
throw e;
}
}
}
說明:這是一個簡單的樣本程式。功能是使用自動對焦功能拍攝一張照片儲存於SD卡根目錄下。需要注意的是要在manifest檔案中聲明相關的許可。本例中許多參數都沒有設定,可以根據具體需要進行適當的修改以滿足特定要求。