android pdf生成 路径 android – 如何从指向PDF文档的URI获取文件路径？

现在我的代码打开了默认下载视图,它只显示我下载的PDF.我选择了一个PDF文件,我得到了这个：

content://com.android.providers.downloads.documents/document/1171

我想得到这个：

/storage/emulated/0/Download/ch22Databases.pdf

我的问题是如何在Android中执行此操作？

我的代码：

public void PDF() {

PDF = (Button) findViewById(R.id.FindPDFBtn);//Finds the button in design and put it into a button variable.

PDF.setOnClickListener(//Listens for a button click.

new View.OnClickListener() {//Creates a new click listener.

@Override

public void onClick(View v) {//does what ever code is in here when the button is clicked

Intent intent = new Intent();

intent.setType("application/pdf");

intent.setAction(Intent.ACTION_GET_CONTENT);

startActivityForResult(Intent.createChooser(intent, "Select a PDF "), SELECT_PDF);

}

}

);

}

@Override

public void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);

//PDF

if (resultCode == RESULT_OK) {

if (requestCode == SELECT_PDF) {

Uri selectedUri_PDF = data.getData();

SelectedPDF = getPDFPath(selectedUri_PDF);

}

}

}

public String getPDFPath(Uri uri) {

String[] projection = { MediaStore.Images.Media.DATA };

Cursor cursor = getContentResolver().query(uri, projection, null, null, null);

int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

cursor.moveToFirst();

return cursor.getString(column_index);

}