參考:
- Taking Photos Simply
- FileProvider
- 項目地址(好多人找我要,我傳到百度云啦,大家自取):鏈接:https://pan.baidu.com/s/1nWsoE0eSXCRP4CqPWAg7Zg 密碼:d865
一. 步驟簡介
要說拍照,如果只是調用系統相機的話,步驟比較簡單,就是利用隱式Intent打開相機,然后會相機會傳回來排好的圖片,傳回來的圖片分為比較小的縮略圖和比較大的原圖,縮略圖的話可以直接進行展示,而原圖的話就要輸出到文件中,因此簡單的拍照分以下步驟:
- 使用隱式Intent打開相機
- 在onActivityResult回調中對圖片進行處理
二. 詳解
-
拍照并獲取縮略圖
??拍照并獲取縮略圖不需要任何權限,只需要調用相機然后獲取結果即可- 調用相機
Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//用來打開相機的Intent
if(takePhotoIntent.resolveActivity(getPackageManager())!=null){//這句作用是如果沒有相機則該應用不會閃退,要是不加這句則當系統沒有相機應用的時候該應用會閃退
startActivityForResult(takePhotoIntent,REQ_CODE);//啟動相機
}
- 獲取結果
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==REQ_CODE&&resultCode==RESULT_OK){
/*縮略圖信息是儲存在返回的intent中的Bundle中的,
* 對應Bundle中的鍵為data,因此從Intent中取出
* Bundle再根據data取出來Bitmap即可*/
Bundle extras = data.getExtras();
Bitmap bitmap = (Bitmap) extras.get("data");
mPicture.setImageBitmap(bitmap);
}
}
-
拍照并獲取完整圖片
??因為完整圖片較大,所以需要將其存儲到文件中,因此需要創建用來存儲圖片的文件,其次又因為存儲圖片需要訪問外存,因此可能需要申請讀寫權限。- 調用相機
private void takePhoto(){
Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//打開相機的Intent
if(takePhotoIntent.resolveActivity(getPackageManager())!=null){//這句作用是如果沒有相機則該應用不會閃退,要是不加這句則當系統沒有相機應用的時候該應用會閃退
File imageFile = createImageFile();//創建用來保存照片的文件
if(imageFile!=null){
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.N){
/*7.0以上要通過FileProvider將File轉化為Uri*/
mImageUri = FileProvider.getUriForFile(this,FILE_PROVIDER_AUTHORITY,imageFile);
}else {
/*7.0以下則直接使用Uri的fromFile方法將File轉化為Uri*/
mImageUri = Uri.fromFile(imageFile);
}
takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT,mImageUri);//將用于輸出的文件Uri傳遞給相機
startActivityForResult(takePhotoIntent, REQUEST_TAKE_PHOTO_CODE);//打開相機
}
}
}
/**
* 創建用來存儲圖片的文件,以時間來命名就不會產生命名沖突
* @return 創建的圖片文件
*/
private File createImageFile() {
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_"+timeStamp+"_";
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File imageFile = null;
try {
imageFile = File.createTempFile(imageFileName,".jpg",storageDir);
} catch (IOException e) {
e.printStackTrace();
}
return imageFile;
}
- 獲取結果
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode== REQUEST_TAKE_PHOTO_CODE &&resultCode==RESULT_OK){
try {
/*如果拍照成功,將Uri用BitmapFactory的decodeStream方法轉為Bitmap*/
Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(mImageUri));
mPicture.setImageBitmap(bitmap);//顯示到ImageView上
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
- 將拍的照片添加到媒體庫以便相冊可以掃描到(當照片存儲在應用目錄下的時候會掃描不到)
- 其實就是發送一條掃描文件的廣播
/**
* 將拍的照片添加到相冊
* @param uri 拍的照片的Uri
*/
private void galleryAddPic(Uri uri){
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
mediaScanIntent.setData(uri);
sendBroadcast(mediaScanIntent);
}
三. 有關7.0以上FileProvider的使用
- 注冊FileProvider
<provider
android:authorities="cn.fonxnickel.officialcamerademo.fileprovider"http://自己定義的authority
android:name="android.support.v4.content.FileProvider"
android:exported="false"
android:grantUriPermissions="true">//獲取臨時讀取存儲的權限
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>
- 新建路徑文件(xml/file_paths)
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path
name="my_images"
path="."/>
</paths>
四. 對拍好的照片進行剪裁
五. 從相冊選取圖片
- 相冊選取圖片和拍照步驟差不多,都是打開應用程序,然后返回Uri,然后進行處理
- 步驟如下:
- 打開相冊
/**
* 打開相冊
*/
private void openAlbum() {
Intent openAlbumIntent = new Intent(Intent.ACTION_GET_CONTENT);
openAlbumIntent.setType("image/*");
startActivityForResult(openAlbumIntent, CHOOSE_PHOTO);//打開相冊
}
- 處理返回的Uri
/*相機或者相冊返回來的數據*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case TAKE_PHOTO:
if (resultCode == RESULT_OK) {
try {
/*如果拍照成功,將Uri用BitmapFactory的decodeStream方法轉為Bitmap*/
Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(mImageUri));
Log.i(TAG, "onActivityResult: imageUri " + mImageUri);
galleryAddPic(mImageUriFromFile);
mPicture.setImageBitmap(bitmap);//顯示到ImageView上
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
break;
case CHOOSE_PHOTO:
Log.i(TAG, "onActivityResult: ImageUriFromAlbum: "+data.getData());
if (resultCode == RESULT_OK) {
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.KITKAT){
handleImageOnKitKat(data);//4.4之后圖片解析
}else {
handleImageBeforeKitKat(data);//4.4之前圖片解析
}
}
break;
default:
break;
}
}
/**
* 4.4版本以下對返回的圖片Uri的處理:
* 就是從返回的Intent中取出圖片Uri,直接顯示就好
* @param data 調用系統相冊之后返回的Uri
*/
private void handleImageBeforeKitKat(Intent data) {
Uri uri = data.getData();
String imagePath = getImagePath(uri,null);
displayImage(imagePath);
}
/**
* 4.4版本以上對返回的圖片Uri的處理:
* 返回的Uri是經過封裝的,要進行處理才能得到真實路徑
* @param data 調用系統相冊之后返回的Uri
*/
@TargetApi(19)
private void handleImageOnKitKat(Intent data) {
String imagePath = null;
Uri uri = data.getData();
if (DocumentsContract.isDocumentUri(this, uri)) {
//如果是document類型的Uri,則提供document id處理
String docId = DocumentsContract.getDocumentId(uri);
if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
String id = docId.split(":")[1];//解析出數字格式的id
String selection = MediaStore.Images.Media._ID + "=" + id;
imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);
} else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {
Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
imagePath = getImagePath(contentUri, null);
}
} else if ("content".equalsIgnoreCase(uri.getScheme())) {
//如果是content類型的uri,則進行普通處理
imagePath = getImagePath(uri, null);
} else if ("file".equalsIgnoreCase(uri.getScheme())) {
//如果是file類型的uri,則直接獲取路徑
imagePath = uri.getPath();
}
displayImage(imagePath);
}
/**
* 將imagePath指定的圖片顯示到ImageView上
*/
private void displayImage(String imagePath) {
if (imagePath != null) {
Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
mPicture.setImageBitmap(bitmap);
} else {
Toast.makeText(this, "failed to get image", Toast.LENGTH_SHORT).show();
}
}
/**
* 將Uri轉化為路徑
* @param uri 要轉化的Uri
* @param selection 4.4之后需要解析Uri,因此需要該參數
* @return 轉化之后的路徑
*/
private String getImagePath(Uri uri, String selection) {
String path = null;
Cursor cursor = getContentResolver().query(uri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
}
cursor.close();
}
return path;
}
六. 源碼
- 布局
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="cn.foxnickel.officialcamerademo.MainActivity">
<Button
android:id="@+id/bt_take_photo"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="@string/take_photo"
android:layout_marginTop="8dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp"/>
<ImageView
android:id="@+id/iv_picture"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:srcCompat="@mipmap/ic_launcher"
android:layout_marginTop="8dp"
app:layout_constraintTop_toBottomOf="@+id/bt_choose_from_album"/>
<Button
android:id="@+id/bt_choose_from_album"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="@string/choose_from_album"
android:layout_marginTop="8dp"
app:layout_constraintTop_toBottomOf="@+id/bt_take_photo"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"/>
</android.support.constraint.ConstraintLayout>
- 主要邏輯
public class MainActivity extends AppCompatActivity {
private final String TAG = getClass().getSimpleName();
private Button mTakePhoto, mChooseFromAlbum;
private ImageView mPicture;
private static final String PERMISSION_WRITE_STORAGE = Manifest.permission.WRITE_EXTERNAL_STORAGE;
private static final int REQUEST_PERMISSION_CODE = 267;
private static final int TAKE_PHOTO = 189;
private static final int CHOOSE_PHOTO = 385;
private static final String FILE_PROVIDER_AUTHORITY = "cn.fonxnickel.officialcamerademo.fileprovider";
private Uri mImageUri, mImageUriFromFile;
private File imageFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/*申請讀取存儲的權限*/
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(PERMISSION_WRITE_STORAGE) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{PERMISSION_WRITE_STORAGE}, REQUEST_PERMISSION_CODE);
}
}
mPicture = (ImageView) findViewById(R.id.iv_picture);
mTakePhoto = (Button) findViewById(R.id.bt_take_photo);
mChooseFromAlbum = (Button) findViewById(R.id.bt_choose_from_album);
mTakePhoto.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
takePhoto();
}
});
mChooseFromAlbum.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openAlbum();
}
});
}
/**
* 打開相冊
*/
private void openAlbum() {
Intent openAlbumIntent = new Intent(Intent.ACTION_GET_CONTENT);
openAlbumIntent.setType("image/*");
startActivityForResult(openAlbumIntent, CHOOSE_PHOTO);//打開相冊
}
/**
* 拍照
*/
private void takePhoto() {
Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//打開相機的Intent
if (takePhotoIntent.resolveActivity(getPackageManager()) != null) {//這句作用是如果沒有相機則該應用不會閃退,要是不加這句則當系統沒有相機應用的時候該應用會閃退
imageFile = createImageFile();//創建用來保存照片的文件
mImageUriFromFile = Uri.fromFile(imageFile);
Log.i(TAG, "takePhoto: uriFromFile " + mImageUriFromFile);
if (imageFile != null) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
/*7.0以上要通過FileProvider將File轉化為Uri*/
mImageUri = FileProvider.getUriForFile(this, FILE_PROVIDER_AUTHORITY, imageFile);
} else {
/*7.0以下則直接使用Uri的fromFile方法將File轉化為Uri*/
mImageUri = Uri.fromFile(imageFile);
}
takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, mImageUri);//將用于輸出的文件Uri傳遞給相機
startActivityForResult(takePhotoIntent, TAKE_PHOTO);//打開相機
}
}
}
/**
* 創建用來存儲圖片的文件,以時間來命名就不會產生命名沖突
*
* @return 創建的圖片文件
*/
private File createImageFile() {
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File imageFile = null;
try {
imageFile = File.createTempFile(imageFileName, ".jpg", storageDir);
} catch (IOException e) {
e.printStackTrace();
}
return imageFile;
}
/*申請權限的回調*/
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.i(TAG, "onRequestPermissionsResult: permission granted");
} else {
Log.i(TAG, "onRequestPermissionsResult: permission denied");
Toast.makeText(this, "You Denied Permission", Toast.LENGTH_SHORT).show();
}
}
/*相機或者相冊返回來的數據*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case TAKE_PHOTO:
if (resultCode == RESULT_OK) {
try {
/*如果拍照成功,將Uri用BitmapFactory的decodeStream方法轉為Bitmap*/
Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(mImageUri));
Log.i(TAG, "onActivityResult: imageUri " + mImageUri);
galleryAddPic(mImageUriFromFile);
mPicture.setImageBitmap(bitmap);//顯示到ImageView上
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
break;
case CHOOSE_PHOTO:
if (data == null) {//如果沒有選取照片,則直接返回
return;
}
Log.i(TAG, "onActivityResult: ImageUriFromAlbum: " + data.getData());
if (resultCode == RESULT_OK) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
handleImageOnKitKat(data);//4.4之后圖片解析
} else {
handleImageBeforeKitKat(data);//4.4之前圖片解析
}
}
break;
default:
break;
}
}
/**
* 4.4版本以下對返回的圖片Uri的處理:
* 就是從返回的Intent中取出圖片Uri,直接顯示就好
* @param data 調用系統相冊之后返回的Uri
*/
private void handleImageBeforeKitKat(Intent data) {
Uri uri = data.getData();
String imagePath = getImagePath(uri, null);
displayImage(imagePath);
}
/**
* 4.4版本以上對返回的圖片Uri的處理:
* 返回的Uri是經過封裝的,要進行處理才能得到真實路徑
* @param data 調用系統相冊之后返回的Uri
*/
@TargetApi(19)
private void handleImageOnKitKat(Intent data) {
String imagePath = null;
Uri uri = data.getData();
if (DocumentsContract.isDocumentUri(this, uri)) {
//如果是document類型的Uri,則提供document id處理
String docId = DocumentsContract.getDocumentId(uri);
if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
String id = docId.split(":")[1];//解析出數字格式的id
String selection = MediaStore.Images.Media._ID + "=" + id;
imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);
} else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {
Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
imagePath = getImagePath(contentUri, null);
}
} else if ("content".equalsIgnoreCase(uri.getScheme())) {
//如果是content類型的uri,則進行普通處理
imagePath = getImagePath(uri, null);
} else if ("file".equalsIgnoreCase(uri.getScheme())) {
//如果是file類型的uri,則直接獲取路徑
imagePath = uri.getPath();
}
displayImage(imagePath);
}
/**
* 將imagePath指定的圖片顯示到ImageView上
*/
private void displayImage(String imagePath) {
if (imagePath != null) {
Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
mPicture.setImageBitmap(bitmap);
} else {
Toast.makeText(this, "failed to get image", Toast.LENGTH_SHORT).show();
}
}
/**
* 將Uri轉化為路徑
* @param uri 要轉化的Uri
* @param selection 4.4之后需要解析Uri,因此需要該參數
* @return 轉化之后的路徑
*/
private String getImagePath(Uri uri, String selection) {
String path = null;
Cursor cursor = getContentResolver().query(uri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
}
cursor.close();
}
return path;
}
/**
* 將拍的照片添加到相冊
*
* @param uri 拍的照片的Uri
*/
private void galleryAddPic(Uri uri) {
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
mediaScanIntent.setData(uri);
sendBroadcast(mediaScanIntent);
}
}