Question

以下代码在冰淇淋三明治上完美运行，但它在Jelly Bean和Kitkat上强制关闭。请帮帮我。

MainActivity.java

package com.example.final_cam;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {
final static String DEBUG_TAG = "MainActivity";
  private Camera camera;
  private int cameraId = 0;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

     // do we have a camera?
    if (!getPackageManager()
        .hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
      Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG)
          .show();
    } else {
      cameraId = findFrontFacingCamera();
      if (cameraId < 0) {
        Toast.makeText(this, "No front facing camera found.",
            Toast.LENGTH_LONG).show();
      } else {
        camera = Camera.open(cameraId);
      }
    }
}

 public void onClick(View view) {
        camera.takePicture(null, null,
            new PhotoHandler(getApplicationContext()));
      }
  private int findFrontFacingCamera() {
        int cameraId = -1;
        // Search for the front facing camera
        int numberOfCameras = Camera.getNumberOfCameras();
        for (int i = 0; i < numberOfCameras; i++) {
          CameraInfo info = new CameraInfo();
          Camera.getCameraInfo(i, info);
          if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
            Log.d(DEBUG_TAG, "Camera found");
            cameraId = i;
            break;
          }
        }
        return cameraId;
      }
  @Override
  protected void onPause() {
    if (camera != null) {
      camera.release();
      camera = null;
    }
    super.onPause();
  }
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

PhotoHandler.java

package com.example.final_cam;

import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.annotation.SuppressLint;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Environment;
import android.util.Log;
import android.widget.Toast;

public class PhotoHandler implements PictureCallback {
private final Context context;
 public PhotoHandler(Context context) {
        this.context = context;
      }
@SuppressLint("SimpleDateFormat")
@Override
public void onPictureTaken(byte[] data, Camera camera) {
    // TODO Auto-generated method stub
    File pictureFileDir = getDir();

    if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {

      Log.d(MainActivity.DEBUG_TAG, "Can't create directory to save image.");
      Toast.makeText(context, "Can't create directory to save image.",
          Toast.LENGTH_LONG).show();
      return;       
}
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
    String date = dateFormat.format(new Date());
    String photoFile = "Picture_" + date + ".jpg";

    String filename = pictureFileDir.getPath() + File.separator + photoFile;

    File pictureFile = new File(filename);  

try {
      FileOutputStream fos = new FileOutputStream(pictureFile);
      fos.write(data);
      fos.close();
      Toast.makeText(context, "New Image saved:" + photoFile,
          Toast.LENGTH_LONG).show();
    } catch (Exception error) {
      Log.d(MainActivity.DEBUG_TAG, "File" + filename + "not saved: "
          + error.getMessage());
      Toast.makeText(context, "Image could not be saved.",
          Toast.LENGTH_LONG).show();
    }

}

 private File getDir() {
        File sdDir = Environment
          .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        return new File(sdDir, "CameraAPIDemo");
      }
    }

我使用了链接中给出的代码...... http://www.vogella.com/tutorials/AndroidCamera/article.html 它在我的Galaxy Tab（冰淇淋三明治）中成功运行，但是当我点击Jelly Bean和Kitkat的Make Photo按钮时强制关闭。请指导我哪里出错......以及要做出的所有改变...... ??

Answer 1

您应该发布您在日志中看到的实际错误（异常/堆栈跟踪）。

然而，看起来你永远不会开始相机预览。虽然它可能适用于某些制造商的设备，但您需要先启动相机预览才能拍照。这意味着您需要预览目标（SurfaceView或SurfaceTexture），并且需要在Surface生效后开始预览。

有关详细信息，请查看Android开发者网站上的示例相机应用： Building a camera app

Android相机API App力在Jelly Bean中单击按钮时关闭

1 个答案: