Android 对发送邮件感到困惑吗

我正试图发送一封附有文件的电子邮件，因此我下载了示例项目并正在处理它。问题是每次我收到相同的邮件时都无法附上文件。对不起，我的英语太差了 到目前为止，我有这个

public class MainActivity extends Activity implements OnClickListener {

EditText et_address, et_subject, et_message;
String address, subject, message, file_path;
Button bt_send, bt_attach;
TextView tv_attach;

private static final int PICK_IMAGE = 100;
Uri URI = null;
int columnindex;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initializeViews();
    bt_send.setOnClickListener(this);
    bt_attach.setOnClickListener(this);

}

private void initializeViews() {
    et_address = (EditText) findViewById(R.id.et_address_id);
    et_subject = (EditText) findViewById(R.id.et_subject_id);
    et_message = (EditText) findViewById(R.id.et_message_id);
    bt_send = (Button) findViewById(R.id.bt_send_id);
    bt_attach = (Button) findViewById(R.id.bt_attach_id);
    tv_attach = (TextView) findViewById(R.id.tv_attach_id);

}

@Override
public void onClick(View v) {
    switch (v.getId()) {

    case R.id.bt_attach_id:
        openGallery();
        break;

    case R.id.bt_send_id:

        try {
            address = et_address.getText().toString();
            subject = et_subject.getText().toString();
            message = et_message.getText().toString();

            String emailAddresses[] = { address };

            Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);

            emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL,
                    emailAddresses);
            emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, subject);
            emailIntent.setType("plain/text");
            emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, message);
            if (URI != null)
                emailIntent.putExtra(Intent.EXTRA_STREAM, URI);

            startActivity(emailIntent);
        } catch (Exception e) {
            e.printStackTrace();
        }

        break;

    }

}

private void openGallery() {
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"),
            PICK_IMAGE);
}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == PICK_IMAGE && resultCode == RESULT_OK) {

        Uri 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]);
        file_path = cursor.getString(columnindex);
        // Log.e("Attachment Path:", attachmentFile);
        tv_attach.setText(file_path);
        URI = Uri.parse("file://" + file_path);
        cursor.close();
    }
}

您对从库返回的Uri的处理看起来过于复杂。您正在获取一个Uri并对其进行处理以生成一个Uri

我认为您的onActivityResult方法应该更像：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == PICK_IMAGE && resultCode == RESULT_OK) {

        URI = data.getData();
    }
}

---

这更好，因为如果外部电子邮件应用程序无法访问文件，将文件：//Uri传递给外部应用程序也不是一种好做法。

错误消息来自哪里？启动了哪个电子邮件应用程序？您是否检查了提供的URI是否为空？如果显示任何错误，则共享堆栈跟踪。Log.dPath control-->，file://+file_path；这是回报file://nullI 不理解您的评论，因为它似乎与我给您的修复无关。您是否尝试将活动结果更改为我上面所写的内容？