这是代码：

final ProgressDialog dlg = new ProgressDialog(this);
    dlg.setTitle("Please wait.");
    dlg.setMessage("Signing up.  Please wait.");
    dlg.show();

    String username_str = username.getText().toString();
    String password_str = password.getText().toString();
    String re_password_str = re_password.getText().toString();
    String email_str = email.getText().toString();
    String phone_str = phone.getText().toString();

    if(!re_password_str.equals(password_str)){
        dlg.dismiss();
        Toast.makeText(this,"Passwords does not match!!",Toast.LENGTH_SHORT).show();
        password.setText("");
        re_password.setText("");
    }else if(email_str.isEmpty()|| phone_str.isEmpty()){
        dlg.dismiss();
        Toast.makeText(this,"email or phone cannot be empty!!",Toast.LENGTH_SHORT).show();

    }else {
        ParseUser new_user = new ParseUser();
        new_user.setUsername(username_str);
        new_user.setPassword(password_str);
        new_user.setEmail(email_str);
        new_user.put("phone",phone_str);
        new_user.signUpInBackground(new SignUpCallback() {
            @Override
            public void done(ParseException e) {
                dlg.dismiss();
                if(e == null){
                    Intent i = new Intent(SignupActivity.this,MainActivity.class);
                    startActivity(i);
                }else{
                    Log.d("signup error",e.toString());
                    Toast.makeText(SignupActivity.this,e.toString(),Toast.LENGTH_SHORT).show();
                }
            }
        });

我已经花了两天时间找到问题,但没有成功……