android调用系统相机拍照后对相片进行裁剪

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

if(FileUtil.isExists(FileUtil.PATH)){
fileName = System.currentTimeMillis()+".jpg";
//设置照相返回图片保存路径
mPhotoFileUri = Uri.fromFile(new File(FileUtil.SDPATH+File.separator+FileUtil.PATH+File.separator+fileName));
intent.putExtra(MediaStore.EXTRA_OUTPUT,mPhotoFileUri);
startActivityForResult(intent,REQUEST_CODE_CAMERA);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == REQUEST_CODE_CAMERA && resultCode == RESULT_OK){
filePath = mPhotoFileUri.getPath();
Log.e(TAG, "onActivityResult: "+filePath);
rotateImageIdNeed(filePath);
}else if(requestCode == PHOTO_REQUEST_CUT && resultCode == RESULT_OK && data != null){
 //imagview来显示裁剪后的图片

mCarPhoto.setImageBitmap(BitmapFactory
.decodeFile(smallFilePath));
if (mPhotoFileUri != null) {
File file = new File(mPhotoFileUri.getPath());
if (file != null && file.exists()) {
file.delete();
}
}
mPhotoFileUri = null;
}

/**旋转图片*/
private void rotateImageIdNeed(String filePath) {
try {
int degree = 0;
ExifInterface exifInterface = new ExifInterface(filePath);//获得图片的前缀
int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION,ExifInterface.ORIENTATION_NORMAL);
switch (orientation){
case ExifInterface.ORIENTATION_ROTATE_90:
degree = 90;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
degree = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_270:
degree = 270;
break;
}
if(degree!=0){
BitmapFactory.Options options = new BitmapFactory.Options();
                    options.inJustDecodeBounds = true;
                    Bitmap bitmap = BitmapFactory.decodeFile(path, options);
                    int width = options.outWidth;
                    int height = options.outHeight;
                    float hh = 360.0f;
                    float ww = 360.0f;
                    int be = 1;// be=1表示不缩放
                    if (width > height && width > ww) {// 如果 宽度大于高度并且
                                                        // 宽度大于固定宽度时缩放
                        be = (int) (width / ww) + 1;
                    }
                    if (height > width && height > hh) {// 如果 高度大于宽度并且
                                                        // 高度大于国定高度时缩放
                        be = (int) (height / hh) + 1;
                    }
                    if (be <= 0) {
                        be = 1;
                    }
                    options.inSampleSize = be;
                    options.inJustDecodeBounds = false;
                 
bitmap = BitmapFactory.decodeFile(filePath,options);
//旋转图片动作
Matrix matrix = new Matrix();
matrix.postRotate(degree);
//创建新图片
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix,true);
FileUtil.saveBitmap2File(resizedBitmap,filePath,100);
if (mHandler != null) {
mHandler.sendEmptyMessage(MSG_TO_CROP_IMAGE);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
这里用到了handler发送一个裁剪意图，在handler里去处理裁剪，这里用到WeakReference弱引用，来防止内存溢出。想了解
弱引用的使用，请看我下一篇博客。

private class InnerHandler extends Handler{
private WeakReference<HeadActivity> mRef;
public InnerHandler(HeadActivity obj){
mRef = new WeakReference<HeadActivity>(obj);
}

@Override
public void handleMessage(Message msg) {
if(mRef == null || mRef.get() == null){
return ;
}
if(msg.what == PHOTO_REQUEST_CUT){
mRef.get().cropPhoto();
}
}
}
public void cropPhoto(){
startPhotoZoom(mPhotoFileUri);
}
下面开始真正的图片的裁剪

/**开始剪切图片*/
private void startPhotoZoom(Uri uri) {
Intent intent= new Intent("com.android.camera.action.CROP");
intent.setDataAndType(uri,"image/*");
//下面这个crop=true是设置在开启的Intent中设置显示的view可裁剪
intent.putExtra("crop","true");
// aspectX aspectY 是宽高的比例
intent.putExtra("aspectX",1);
intent.putExtra("aspectY",1);
// outputX outputY 是裁剪图片宽高
intent.putExtra("outputX", 800);
intent.putExtra("outputY", 800);
//是否将数据保留在Bitmap中返回
intent.putExtra("return-data", false);
// 当图片的宽高不足时，会出现黑边，去除黑边
intent.putExtra("scale", true);
intent.putExtra("scaleUpIfNeeded", true);
smallFilePath = FileUtil.SDPATH + File.separator + FileUtil.PATH
+ File.separator + System.currentTimeMillis() + ".jpg";
intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(new File(smallFilePath)));
intent.putExtra("outputFormat", "JPEG");// 返回格式
startActivityForResult(intent,PHOTO_REQUEST_CUT);
}

public class FileUtil {
public static final String SDPATH = Environment.getExternalStorageDirectory().getAbsolutePath();
public static final String PATH = "congmingtou";

/**
* 是否支持SDCard
*/
public static boolean isSupportSDCard() {
return Environment.getExternalStorageDirectory().exists();
}

/**
* 检测文件或者路径是否存在
* <p>
* 可以给值为Null，如果给值null,判断路径是否存在
*/

public static boolean isExists(String path, String fileName) {
if (null == path && null == fileName) {
return false;
}
String name;
name = SDPATH + File.separator + path;
File file = new File(name);
if (!file.exists()) {
file.mkdirs();
}
File fileNmae = new File(name, fileName);
return fileNmae.exists();
}

public static boolean isExists(String path) {
if (null == path) {
return false;
}
String name;

name = SDPATH + File.separator + path;

File file = new File(name);
if (!file.exists()) {
file.mkdirs();
}
return file.exists();
}

/**
* 检查SD卡是否可用
*/
public static boolean isAvailable() {
return Environment.MEDIA_MOUNTED.equals(Environment
.getExternalStorageState());
}

/***
*保存bitmap对象到文件中
* @param bm
* @param path
* @param quality
* @return
*/
public static boolean saveBitmap2File(Bitmap bm, String path, int quality) {
if (null == bm || bm.isRecycled()) {
return false;
}
try {
File file = new File(path);
if (file.exists()) {
file.delete();
}
BufferedOutputStream bos = new BufferedOutputStream(
new FileOutputStream(file));
bm.compress(Bitmap.CompressFormat.JPEG, quality, bos);
bos.flush();
bos.close();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
} finally {
if (null != bm) {
if (!bm.isRecycled()) {
bm.recycle();
}
bm = null;
}
}
}
}