无法附加Android应用文件并通过电子邮件发送

Question

"File could not be attached" I am trying to attach an image from my app and send it as an attachment over email. But as soon as I select the image from Gallery, the app crashes. It used to work the first time I executed the app, but now it does not seem to work for some reason. But later I fixed it by updating the line of code to:

        attachmentFile = cursor.getString(columnIndex);
        Log.d("Attachment Path: "," " + attachmentFile);

From my Logcat, I cannot find which statement is causing this issue.

Initially, I was referring to this qeuestion and tried the answers given in this.
" java.lang.NullPointerException: println needs a message ".

"My DespatchActivity"

package com.example.despatch4.resiscafftest;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.net.Uri;
import android.widget.Button;
import android.provider.MediaStore;
import android.database.Cursor;
import android.util.Log;
import android.widget.EditText;

import android.widget.CheckBox;
import android.widget.Toast;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class DespatchActivity extends AppCompatActivity {
private Activity activity;

Button Attachment;
String attachmentFile;
Uri URI = null;
int columnIndex;
private static final int PICK_FROM_GALLERY = 101;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_despatch);
    this.setTitle("Residential Scaffold - Despatch");


    final EditText your_name = (EditText) findViewById(R.id.your_name);
    final EditText company_name = (EditText) findViewById(R.id.company_name);
    final EditText your_phone = (EditText) findViewById(R.id.your_ph);
    final EditText your_jobno = (EditText) findViewById(R.id.your_jobno);
    final EditText your_e_d =   (EditText) findViewById(R.id.your_e_d);
    final EditText job_details = (EditText) findViewById(R.id.job_details);
    final EditText your_date = (EditText) findViewById(R.id.your_date);

    Button email = (Button) findViewById(R.id.post_desp_message);
    Attachment = (Button) findViewById(R.id.bt_attach);

    email.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String name = your_name.getText().toString();
            String companyname = company_name.getText().toString();
            String phone = your_phone.getText().toString();
            String jobno = your_jobno.getText().toString();
            String ed = your_e_d.getText().toString();
            String jobdetails = job_details.getText().toString();
            String date = your_date.getText().toString();

            Intent sendEmail = new Intent(Intent.ACTION_SEND);



            sendEmail.setType("plain/text");
            sendEmail.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{"Zamil@residentialscaffold.com.au"});

            sendEmail.putExtra(android.content.Intent.EXTRA_TEXT, "Name: " + name + '\n' + '\n'  + "Company Name: " + companyname + '\n' + '\n'
                    + '\n' + "Contact Number: " + phone + '\n' + '\n'  + "Job Number: " + jobno + '\n' + '\n'  +  "Erect/Dismantle: " + ed + '\n' + '\n'  + "Job Details: "
                    + jobdetails + '\n' + '\n'  + "Date Required: " + date);
                if (URI != null) {
                sendEmail.putExtra(Intent.EXTRA_STREAM, selectedImage);
            }
            startActivity(Intent.createChooser(sendEmail, "Send mail..."));

        }
    });


    //attach images
    Attachment.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            openFolder();
        }
    });

}

protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
Uri selectedImage = null;    
if (requestCode == PICK_FROM_GALLERY && resultCode == RESULT_OK) {
        selectedImage = data.getData();
        String[] filePathColumn = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
        cursor.moveToFirst();
        columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        attachmentFile = cursor.getString(columnIndex);
        //Log.e("Attachment Path:", " " , attachmentFile);
        Log.d("Attachment Path: ","null" attachmentFile);
        URI = Uri.parse("file://" + attachmentFile);
        cursor.close();
    }
}

@Override
public void onResume() {
    super.onResume();
}

@Override
protected void onStart() {
    super.onStart();

}

@Override
protected void onStop() {
    super.onStop();

}

private boolean isValidEmail(String email) {
    String EMAIL_PATTERN = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
            + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";

    Pattern pattern = Pattern.compile(EMAIL_PATTERN);
    Matcher matcher = pattern.matcher(email);
    return matcher.matches();
}

public void openFolder()
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    intent.putExtra("return-data", true);
    startActivityForResult(Intent.createChooser(intent, "Complete action using"), PICK_FROM_GALLERY);
}

}

As soon as I try to attach a file this is what happens in my Logcat:

 01-23 10:23:48.123 4334-4334/com.example.despatch4.resiscafftest 
 D/Attachment Path:: nullnull

The email client is successfully launched with a toast message "Couldn't attach file".

Thanks in Advance.

Answer 1

sendEmail.putExtra(Intent.EXTRA_STREAM, URI);

change that line to

sendEmail.putExtra(Intent.EXTRA_STREAM, data.getData());

With data.getData() the one you got in onActivityResult() .`

Dont mess around with trying to obtain a path.

Instead use the uri directly.

Much less code too ;-).