做過Android換頭像的都知道如何使用系統的方法選圖片或者拍照換頭像。有幾個intent可以使用:
拍照: new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
選取相冊圖片: new Intent(Intent.ACTION_GET_CONTENT, null);
new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
通常4.4得到的uri,需要以下方法來獲取文件的路徑
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}上面代碼看起來很麻煩。下面介紹個簡單的方法處理不同版本的選擇圖庫bug。
在onActivityResult裏面打個斷點看下返回的數據。首先是4.4系統以下，可以直接從extra中獲得圖片。：
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (data != null) { Bundle extra = data.getExtras(); if (extra != null) { Bitmap photo = null; photo = (Bitmap) extra.get("data"); }
但是在4.4以上系統中，extra爲空，返回圖片的uri在data中。
既然這個時候獲得了圖片uri，我們可以使用系統的方法從uri直接獲取bitmap，不需要先把uri轉化成path，然後獲取文件然後解壓。代碼長這樣：
photo = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data.getData());這個時候獲取的圖片還沒有剪裁，需要像拍照一樣繼續剪裁。
大功告成，這樣不同版本的系統就可以使用相同的選取圖片的代碼了。
完整代碼在這裏:
public class ProfileActivity extends BaseActivity implements OnClickListener { private final static int REQ_CAP_AVATAR = 1;//拍照 private final static int REQ_GET_AVATAR = 2;//選取照片 private final static int REQ_CROP = 3;//剪裁 private final static int REQ_UPDATE = 10;//上傳 @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == RESULT_OK) { Intent result = getIntent(); if (requestCode == REQ_GET_AVATAR || requestCode == REQ_CROP) { if (data != null) { Bitmap photo = null; Bundle extra = data.getExtras(); if (extra != null) { photo = (Bitmap) extra.get("data"); } if (photo == null && data.getData() != null) { try { photo = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data.getData());//這個時候圖片沒有進入剪裁，需要再次建材圖片 if (photo != null) { Intent intent = new Intent("com.android.camera.action.CROP"); photo.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(MyApp.getMyCacheDir() + "avatar.jpg")); intent.setDataAndType(Uri.fromFile(new File(MyApp.getMyCacheDir() + "avatar.jpg")), "image/*"); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); intent.putExtra("outputX", 100); intent.putExtra("outputY", 100); intent.putExtra("return-data", true); startActivityForResult(intent, REQ_CROP); return; } } catch (IOException e) { e.printStackTrace(); } } if (photo != null) { try { photo.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(MyApp.getMyCacheDir() + "avatar.jpg")); } catch (FileNotFoundException e) { e.printStackTrace(); } } mMasterIconView.setImageBitmap(photo); result.putExtra("photo", photo); doUpload(); } } else if (requestCode == REQ_CAP_AVATAR) { Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(Uri.fromFile(new File(MyApp.getMyCacheDir() + "avatar.jpg")), "image/*"); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); intent.putExtra("outputX", 100); intent.putExtra("outputY", 100); intent.putExtra("return-data", true); startActivityForResult(intent, REQ_CROP); } setResult(RESULT_OK, result); } } @Override public void onClick(View v) { Intent intent; switch (v.getId()) { case R.id.pic_capture://拍照 if (ViewHelper.getAlpha(mPicPickMain) == 1f && mDetail != null) { Uri fileUri = Uri.fromFile(new File(MyApp.getMyCacheDir() + "avatar.jpg")); intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); startActivityForResult(intent, REQ_CAP_AVATAR); dismissPicPick(); } break; case R.id.pic_get://選擇相冊 if (ViewHelper.getAlpha(mPicPickMain) == 1f && mDetail != null) { intent = new Intent(Intent.ACTION_GET_CONTENT, null); new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); intent.setType("image/*"); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); intent.putExtra("outputX", 100); intent.putExtra("outputY", 100); intent.putExtra("return-data", true); startActivityForResult(intent, REQ_GET_AVATAR); dismissPicPick(); } break; } } //上傳圖片 private void doUpload() {} }