android平台拍照后先剪裁再显示图片实现方法

package cn.testcamera;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {
	private Button mButton;
	private ImageView mImageView;
	private File mPhotoFile;
	private String mPhotoPath;
	private Uri mPhotoOnSDCardUri;
    public final static int CAMERA_RESULT=777;
    public final static int CAMERA_RESULT_CUT=888;
    public final static int CAMERA_RESULT_CUT_OVER=999;
    public final static String TAG="xx";
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		mButton = (Button) findViewById(R.id.button);
		mButton.setOnClickListener(new ButtonOnClickListener());
		mImageView = (ImageView) findViewById(R.id.imageView);

	}

	private class ButtonOnClickListener implements View.OnClickListener {
		public void onClick(View v) {
			try {
				Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
				mPhotoPath="mnt/sdcard/DCIM/Camera/"+getPhotoFileName();
				mPhotoFile = new File(mPhotoPath);
				if (!mPhotoFile.exists()) {
					mPhotoFile.createNewFile();
				}
				mPhotoOnSDCardUri=Uri.fromFile(mPhotoFile);
			    intent.putExtra(MediaStore.EXTRA_OUTPUT, mPhotoOnSDCardUri);
			    //拍照后显示此图片
		        //startActivityForResult(intent,CAMERA_RESULT);
		        //拍照后先修改再显示此图片
		        startActivityForResult(intent,CAMERA_RESULT_CUT);
			} catch (Exception e) {
			}
		}
	}
	
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		super.onActivityResult(requestCode, resultCode, data);
		//1   拍照后显示照片
		if (requestCode==CAMERA_RESULT) {
			 Bitmap bitmap = BitmapFactory.decodeFile(mPhotoPath, null);  
			 mImageView.setImageBitmap(bitmap);
		}
		//2   拍照后剪切照片,然后显示
		//2.1拍照且剪裁
		if (requestCode == CAMERA_RESULT_CUT) {
			Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,mPhotoOnSDCardUri);
			sendBroadcast(intent);
			try {
				Thread.sleep(2000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			Uri systemImageUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
			ContentResolver contentResolver = getContentResolver();
			Cursor cursor = contentResolver.query(systemImageUri, null,
					MediaStore.Images.Media.DISPLAY_NAME + "='"
							+ mPhotoFile.getName() + "'", null, null);
			Uri photoUriInMedia = null;
			if (cursor != null && cursor.getCount() > 0) {
				cursor.moveToLast();
				long id = cursor.getLong(0);
				photoUriInMedia = ContentUris.withAppendedId(systemImageUri, id);
			}
			cursor.close();
			Intent in = new Intent("com.android.camera.action.CROP");
			//需要裁减的图片格式
			in.setDataAndType(photoUriInMedia, "image/*");
			//允许裁减
			in.putExtra("crop", "true");
			//剪裁后ImageView显时图片的宽
			in.putExtra("outputX", 250);
			//剪裁后ImageView显时图片的高
			in.putExtra("outputY", 250);
			//设置剪裁框的宽高比例
			in.putExtra("aspectX", 1);
			in.putExtra("aspectY", 1);
			in.putExtra("return-data", true);
			startActivityForResult(in, CAMERA_RESULT_CUT_OVER);
		}
		//2.2显示
		if (requestCode==CAMERA_RESULT_CUT_OVER) {
			//剪切图片的时候,若"放弃"则回答的data为null
			if (data!=null) {
				Bitmap bitmap = (Bitmap) data.getExtras().get("data");
				mImageView.setImageBitmap(bitmap);
			}
		}
	}
	
	private String getPhotoFileName() {
		Date date = new Date(System.currentTimeMillis());
		SimpleDateFormat dateFormat = new SimpleDateFormat("'IMG'_yyyyMMdd_HHmmss");
		return dateFormat.format(date) + ".jpg";
	}
}