我有开发应用程序，从SD卡获取所有类型的路径（图像，音频，视频）... 它适用于打开默认Android浏览器（图库）。但是当我在其他应用程序中打开SD卡时，它会抛出NullPointer。例如，我通过我的应用程序打开SD卡使用资源管理器应用程序显示空指针异常... 我将保存图像路径到SQlite并从另一个活动中获取SQLite的内容。但是此Explorer应用程序显示所有类型，不仅适用于指定类型。 （示例i选择图像按钮，但它显示所有类型）。
radio_group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup rd_group, int checked_id) {
checking = null;
switch(checked_id) {
case R.id.radio_image:
checking = "image";
break;
case R.id.radio_audio:
checking = "audio";
break;
case R.id.radio_video:
checking = "video";
break;
}
}
});
// I have a radio button for type of content will shown only
select_content.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if(checking.equals("")) {
Toast.makeText(getApplicationContext(), "Please select the content type", Toast.LENGTH_SHORT).show();
return;
}
// when i select image, show image content only in SDcard.
// When i select audio, show only audio contents.
// when i select video, show only video contents.
if(checking.equals("image")) {
Intent intent_image = new Intent();
intent_image.setType("image/*");
intent_image.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent_image, "Select Image"), SELECT_IMAGE_DIALOG);
}
if(checking.equals("audio")) {
Intent intent_audio = new Intent();
intent_audio.setType("audio/*");
intent_audio.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent_audio, "Select Audio"), SELECT_AUDIO_DIALOG);
}
if(checking.equals("video")) {
Intent intent_video = new Intent();
intent_video.setType("video/*");
intent_video.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent_video, "Select Video"), SELECT_VIDEO_DIALOG);
}
}
});
public void onActivityResult(int requestCode, int resultCode, Intent result) {
// imagePath = null;
if (requestCode == SELECT_IMAGE_DIALOG) {
if (resultCode == Activity.RESULT_OK) {
Uri data = result.getData();
Log.d("DATA", data.toString());
selected_Path = getPath(data);
final_path.getBytes();
selected_path_text.setText(final_path);
Log.d("Image Path", final_path);
}
}
if (requestCode == SELECT_AUDIO_DIALOG) {
if (resultCode == RESULT_OK) {
Uri data = result.getData();
Log.d("DATA", data.toString());
selected_Path = getPath(data);
final_path.getBytes();
selected_path_text.setText(final_path);
Log.d("Audio Path", final_path);
}
}
if (requestCode == SELECT_VIDEO_DIALOG) {
if (resultCode == RESULT_OK) {
Uri data = result.getData();
Log.d("DATA", data.toString());
selected_Path = getPath(data);
final_path.getBytes();
selected_path_text.setText(final_path);
Log.d("Video Path", final_path);
}
}
}
private String getPath(Uri data) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(data, projection, null, null, null);
column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
final_path = cursor.getString(column_index);
Log.d("Image Path", final_path);
return cursor.getString(column_index);
}
答案 0 :(得分：3)
试试这个：
Intent i = new Intent(Intent.android.provider.MediaStore.{File type for getting path }.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_CODE);
if (requestCode == RESULT_CODE && resultCode == RESULT_OK && null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.{FILETYPE }.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
path = cursor.getString(columnIndex);
cursor.close();
}
答案 1 :(得分：0)
我们也可以在ContentProviders中使用：
private Cursor mCursor;
if (audio) {
mUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
mCursor = mContentResolver.query(mUri, null, null, null, null);
if (mCursor != null && mCursor.moveToFirst()) {
do {
mFileName = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
mFilePath = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Audio.Media.DATA));
} while (mCursor.moveToNext());
}
}
if (video) {
mUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
mCursor = mContentResolver.query(mUri, null, null, null, null);
if (mCursor != null && mCursor.moveToFirst()) {
do {
mFileName = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Video.Media.DISPLAY_NAME));
mFilePath = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Video.Media.DATA));
} while (mCursor.moveToNext());
}
}
if (image) {
mUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
mCursor = mContentResolver.query(mUri, null, null, null, null);
if (mCursor != null && mCursor.moveToFirst()) {
do {
mFileName = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Images.Media.DISPLAY_NAME));
mFilePath = mCursor
.getString(mCursor
.getColumnIndex(MediaStore.Images.Media.DATA));
} while (mCursor.moveToNext());
}
}
mCursor.close();