android实现简单拍照功能

拍照可以调用系统的相机进行拍照，拍完保存到相应的SD卡目录。最近要用到拍照这个功能，首先试了下调用相机拍照，保存到相应目录，然后用imageview显示的时候感觉，很模糊。可能是图片被压缩的太狠了。所以自己使用Camera写了一个拍照的功能，拍出来的还挺清晰的，不过文件有点大一张图片差不多1.7M。如果想拍高清图可以使用下面的代码。

代码很简单，我就不做过多解释了。

package com.example.testsimple;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.text.format.DateFormat;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

 private SurfaceView surfaceView;
  private SurfaceHolder surfaceHolder;
  private Camera camera;
  private File picture;
  private Button btnSave;
  private final static String TAG = "CameraActivity";
  private ImageView open_picIcon;

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

    /* Intent intent=new Intent(MainActivity.this,MyCameraActivity.class);
    startActivity(intent);
    finish();*/
    setupViews();
  }

  private void setupViews(){
    surfaceView = (SurfaceView) findViewById(R.id.camera_preview); // Camera interface to instantiate components
    surfaceHolder = surfaceView.getHolder(); // Camera interface to instantiate components
    surfaceHolder.addCallback(surfaceCallback); // Add a callback for the SurfaceHolder
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 

    btnSave = (Button) findViewById(R.id.save_pic);
    open_picIcon=(ImageView) findViewById(R.id.open_picIcon);

    btnSave.setOnClickListener(new OnClickListener() { 

      @Override
      public void onClick(View v) {
       surfaceView.setVisibility(View.VISIBLE);
       open_picIcon.setVisibility(View.GONE);
        takePic();
      }
    });
  } 

  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_CAMERA
        || keyCode == KeyEvent.KEYCODE_SEARCH) {
      takePic();
      return true;
    }
    return super.onKeyDown(keyCode, event);
  } 

  private void takePic() { 

    camera.stopPreview();// stop the preview 

    camera.takePicture(null, null, pictureCallback); // picture
  } 

  // Photo call back
  Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {
    //@Override
    public void onPictureTaken(byte[] data, Camera camera) {
      new SavePictureTask().execute(data);
      camera.startPreview();
    }
  }; 

  // save pic
  class SavePictureTask extends AsyncTask<byte[], String, String> {
    @Override
    protected String doInBackground(byte[]... params) {
      String fname = DateFormat.format("yyyyMMddhhmmss", new Date()).toString()+".jpg"; 

      Log.i(TAG, "fname="+fname+";dir="+Environment.getExternalStorageDirectory());
      //picture = new File(Environment.getExternalStorageDirectory(),fname);// create file 

      picture = new File(Environment.getExternalStorageDirectory()+"/images/"+fname);
      File file= picture.getParentFile();
      if(!file.exists())
           file.mkdir();
      try {
        FileOutputStream fos = new FileOutputStream(picture.getPath()); // Get file output stream
        fos.write(params[0]); // Written to the file
        fos.close();
      } catch (Exception e) {
        e.printStackTrace();
      }
      return null;
    }
    @Override
    protected void onPostExecute(String result) {
     // TODO Auto-generated method stub
     super.onPostExecute(result);

     Bitmap bitmap=getDiskBitmap(picture.getPath());
     surfaceView.setVisibility(View.GONE);
     open_picIcon.setVisibility(View.VISIBLE);
     open_picIcon.setImageBitmap(bitmap);
    }

  }
  private Bitmap getDiskBitmap(String pathString)
  {
    Bitmap bitmap = null;
    try
    {
      File file = new File(pathString);
      if(file.exists())
      {
        bitmap = BitmapFactory.decodeFile(pathString);
      }
    } catch (Exception e)
    {
      // TODO: handle exception
    } 

    return bitmap;
  }
  // SurfaceHodler Callback handle to open the camera, off camera and photo size changes
  SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() { 

    public void surfaceCreated(SurfaceHolder holder) {
      Log.i(TAG, "surfaceCallback====");
      camera = Camera.open(); // Turn on the camera
      try {
        camera.setPreviewDisplay(holder); // Set Preview
      } catch (IOException e) {
        camera.release();// release camera
        camera = null;
      }
    } 

    public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
      Log.i(TAG,"====surfaceChanged");
      Camera.Parameters parameters = camera.getParameters(); // Camera parameters to obtain
      parameters.setPictureFormat(PixelFormat.JPEG);// Setting Picture Format
//     parameters.set("rotation", 180); // Arbitrary rotation
      camera.setDisplayOrientation(0);
      parameters.setPreviewSize(400, 300); // Set Photo Size
      camera.setParameters(parameters); // Setting camera parameters
      camera.startPreview(); // Start Preview
    } 

    public void surfaceDestroyed(SurfaceHolder holder) {
      Log.i(TAG,"====surfaceDestroyed");
      camera.stopPreview();// stop preview
      camera.release(); // Release camera resources
      camera = null;
    }
  };
}

拍完以后自动保存到SD卡中的images目录下

下面是图片存放路径

1.8M 确实有点大，不过是高清图片

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