效果图
现在很多应用中都会要求用户上传一张图片来作为头像，首先我在这接收使用相机拍照和在相册中选择图片。接下来先上效果图：
实现代码
1. 布局文件：
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"tools:context="com.gyq.cameraalbumtest.MainActivity"><Buttonandroid:id="@+id/btn_take_photo"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="take photo"/><Buttonandroid:id="@+id/choose_from_album"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="choose from album"/><ImageViewandroid:id="@+id/iv_picture"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center_horizontal"/></LinearLayout>
2. MainActivity.java逻辑代码：
public class MainActivity extends AppCompatActivity {public static final int TAKE_PHOTO = 1;public static final int CHOOSE_PHOTO = 2;private Button mTakePhoto, mChoosePhoto;private ImageView picture;private Uri imageUri;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mTakePhoto = (Button) findViewById(R.id.btn_take_photo);mChoosePhoto = (Button) findViewById(R.id.choose_from_album);picture = (ImageView) findViewById(R.id.iv_picture);mTakePhoto.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//创建file对象，用于存储拍照后的图片；File outputImage = new File(getExternalCacheDir(), "output_image.jpg");try {if (outputImage.exists()) {outputImage.delete();}outputImage.createNewFile();} catch (Exception e) {e.printStackTrace();}if (Build.VERSION.SDK_INT >= 24) {imageUri = FileProvider.getUriForFile(MainActivity.this,"com.gyq.cameraalbumtest.fileprovider", outputImage);} else {imageUri = Uri.fromFile(outputImage);}//启动相机程序Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);startActivityForResult(intent, TAKE_PHOTO);}});mChoosePhoto.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);} else {openAlbum();}}});}//打开相册private void openAlbum() {Intent intent = new Intent("android.intent.action.GET_CONTENT");intent.setType("image/*");startActivityForResult(intent, CHOOSE_PHOTO);}@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {switch (requestCode) {case 1:if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {openAlbum();} else {Toast.makeText(this, "you denied the permission", Toast.LENGTH_SHORT).show();}break;}}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {switch (requestCode) {case TAKE_PHOTO:if (resultCode == RESULT_OK) {try {Bitmap bm = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));picture.setImageBitmap(bm);} catch (Exception e) {e.printStackTrace();}}break;case CHOOSE_PHOTO:if (resultCode == RESULT_OK) {if (Build.VERSION.SDK_INT >= 19) {//4.4及以上的系统使用这个方法处理图片；handleImageOnKitKat(data);} else {handleImageBeforeKitKat(data); //4.4及以下的系统使用这个方法处理图片}}default:break;}}private void handleImageBeforeKitKat(Intent data) {Uri uri = data.getData();String imagePath = getImagePath(uri, null);displayImage(imagePath);}private String getImagePath(Uri uri, String selection) {String path = null;//通过Uri和selection来获取真实的图片路径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;}private void displayImage(String imagePath) {if (imagePath != null) {Bitmap bitmap = BitmapFactory.decodeFile(imagePath);picture.setImageBitmap(bitmap);} else {Toast.makeText(this, "failed to get image", Toast.LENGTH_SHORT).show();}}/*** 4.4及以上的系统使用这个方法处理图片** @param data*/@TargetApi(19)private void handleImageOnKitKat(Intent data) {String imagePath = null;Uri uri = data.getData();if (DocumentsContract.isDocumentUri(this, uri)) {//如果document类型的Uri,则通过document来处理String docID = DocumentsContract.getDocumentId(uri);if ("com.android.providers.media.documents".equals(uri.getAuthority())) {String id = docID.split(":")[1];//解析出数字格式的idString 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/piblic_downloads"), Long.valueOf(docID));imagePath = getImagePath(contentUri, null);}} else if ("content".equalsIgnoreCase(uri.getScheme())) {//如果是content类型的uri，则使用普通方式使用imagePath = getImagePath(uri, null);} else if ("file".equalsIgnoreCase(uri.getScheme())) {//如果是file类型的uri，直接获取路径即可imagePath = uri.getPath();}displayImage(imagePath);}}
3. 清单文件：
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="/apk/res/android"package="com.gyq.cameraalbumtest"><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/><applicationandroid:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:supportsRtl="true"android:theme="@style/AppTheme"><activity android:name=".MainActivity"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><providerandroid:authorities="com.gyq.cameraalbumtest.fileprovider"android:name="android.support.v4.content.FileProvider"android:exported="false"android:grantUriPermissions="true"><meta-data android:name="android.support.FILE_PROVIDER_PATHS"android:resource="@xml/file_paths"/></provider></application></manifest>
4. xml 文件夹中的文件
<?xml version = "1.0" encoding = "utf-8"?><paths xmlns:android = "/apk/res/android"><external-path name = "my_images" path = ""></external-path></paths>
OK，完成收工。请继续关注我的博客。谢谢！
