解决在转发一条内容为满的彩信，删除主题FWD，发送的时候提示转化为短信。

问题描述：

1.长按一条输入内容为满的彩信，选择转发

2.输入联系人-删除主题FWD-发送

测试结果为：提示正转化为短信（见附件）

预期结果为：不应该有提示，应该还是彩信

测试结果图为：

根据提示的Toast内容“Converting to text message...”进行代码最终进行代码定位到ComposeMessageActivity类的showConvertToSmsToast（）方法，并打印堆栈：

private void showConvertToSmsToast() {

        Log.d("bill",Log.getStackTraceString(new Throwable()));

        Toast.makeText(this, R.string.converting_to_text_message, Toast.LENGTH_SHORT).show();

    }

通过打印堆栈我们可以看出方法的调用流程，我们从下往上来分析到底是哪一个环节除了问题，首先分析ComposeMessageActivity类的onProtocolChanged（）方法：

@Override

    public void onProtocolChanged(final boolean convertToMms) {<TAG 1-1>

        // Have to make sure we're on the UI thread. This function can be called off of the UI

        // thread when we're adding multi-attachments

        runOnUiThread(new Runnable() {

            @Override

            public void run() {

                if (mShowTwoButtons) {

                    showTwoSmsOrMmsSendButton(convertToMms);

                } else {

                    showSmsOrMmsSendButton(convertToMms);

                }





                if (convertToMms) {

                    // In the case we went from a long sms with a counter to an mms because

                    // the user added an attachment or a subject, hide the counter --

                    // it doesn't apply to mms.

                    mTextCounter.setVisibility(View.GONE);



                    if (mShowTwoButtons) {

                        mTextCounterSec.setVisibility(View.GONE);

                    }

                    showConvertToMmsToast();

                } else {

                    mTextCounter.setVisibility(View.VISIBLE);

                    showConvertToSmsToast();

                }

            }

        });

   

从上面代码我们分析，当彩信已经发送的时候，该方法不应该在调用，而是应该在输入短息内容的时候进行调用。那我们接着分析WorkingMessage类的updateState（）方法，setSubject（）方法，removeSubjectIfEmpty（）方法，send（）方法和sendMessage（）方法。

   private void updateState(int state, boolean on, boolean notify) {<TAG1-2>

        if (!sMmsEnabled) {

            // If Mms isn't enabled, the rest of the Messaging UI should not be using any

            // feature that would cause us to to turn on any Mms flag and show the

            // "Converting to multimedia..." message.

            return;

        }

        int oldState = mMmsState;

        if (on) {

            mMmsState |= state;

        } else {

            mMmsState &= ~state;

        }



        // If we are clearing the last bit that is not FORCE_MMS,

        // expire the FORCE_MMS bit.

        if (mMmsState == FORCE_MMS && ((oldState & ~FORCE_MMS) > 0)) {

            mMmsState = 0;

        }



        // Notify the listener if we are moving from SMS to MMS

        // or vice versa.

        if (notify) {

            if (oldState == 0 && mMmsState != 0) {

                mStatusListener.onProtocolChanged(true);

            } else if (oldState != 0 && mMmsState == 0) {

                mStatusListener.onProtocolChanged(false);

            }

        }



        if (oldState != mMmsState) {

            if (Log.isLoggable(LogTag.APP, Log.VERBOSE)) LogTag.debug("updateState: %s%s = %s",

                    on ? "+" : "-",

                    stateString(state), stateString(mMmsState));

        }

    }

    public void setSubject(CharSequence s, boolean notify) {<TAG 1-3>

        mSubject = s;

        updateState(HAS_SUBJECT, (s != null), notify);

        if (mSlideshow != null) {

            mSlideshow.setSubjectSize((s == null) ? 0 : s.toString().getBytes().length);

        }

    }



    private void removeSubjectIfEmpty(boolean notify) {<TAG1-4>

        if (!hasSubject()) {

            setSubject(null, notify);

        }

    }

    public void send(final String recipientsInUI) {<TAG1-5>

        long origThreadId = mConversation.getThreadId();



        if (Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE)) {

            LogTag.debug("send origThreadId: " + origThreadId);

        }



        removeSubjectIfEmpty(true /* notify */);



        // Get ready to write to disk.

        prepareForSave(true /* notify */);



        // We need the recipient list for both SMS and MMS.

        final Conversation conv = mConversation;

        String msgTxt = mText.toString();



        if (requiresMms() || addressContainsEmailToMms(conv, msgTxt)) {

            // uaProfUrl setting in mms_config.xml must be present to send an MMS.

            // However, SMS service will still work in the absence of a uaProfUrl address.

            if (MmsConfig.getUaProfUrl() == null) {

                String err = "WorkingMessage.send MMS sending failure. mms_config.xml is " +

                        "missing uaProfUrl setting.  uaProfUrl is required for MMS service, " +

                        "but can be absent for SMS.";

                RuntimeException ex = new NullPointerException(err);

                Log.e(TAG, err, ex);

                // now, let's just crash.

                throw ex;

            }



            // Make local copies of the bits we need for sending a message,

            // because we will be doing it off of the main thread, which will

            // immediately continue on to resetting some of this state.

            final Uri mmsUri = mMessageUri;

            final PduPersister persister = PduPersister.getPduPersister(mActivity);



            final SlideshowModel slideshow = mSlideshow;

            final CharSequence subject = mSubject;

            final boolean textOnly = mAttachmentType == TEXT;



            if (Log.isLoggable(LogTag.TRANSACTION, Log.VERBOSE)) {

                LogTag.debug("Send mmsUri: " + mmsUri);

            }



            // Do the dirty work of sending the message off of the main UI thread.

            new Thread(new Runnable() {

                @Override

                public void run() {

                    final SendReq sendReq = makeSendReq(conv, subject);



                    // Make sure the text in slide 0 is no longer holding onto a reference to

                    // the text in the message text box.

                    slideshow.prepareForSend();

                    sendMmsWorker(conv, mmsUri, persister, slideshow, sendReq, textOnly);



                    updateSendStats(conv);

                }

            }, "WorkingMessage.send MMS").start();

        } else {

            // Same rules apply as above.

            // add user's signature first if this feature is enabled.

            String text = mText.toString();

            SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mActivity);

            if (sp.getBoolean("pref_key_enable_signature", false)) {

                String signature = (sp.getString("pref_key_edit_signature", "")).trim();

                if (signature.length() > 0) {

                    String sigBlock = "\n" + signature;

                    if (!text.endsWith(sigBlock)) {

                        // Signature should be written behind the text in a

                        // newline while the signature has changed.

                        text += sigBlock;

                    }

                }

            }

            final String msgText = text;

            new Thread(new Runnable() {

                @Override

                public void run() {

                    preSendSmsWorker(conv, msgText, recipientsInUI);



                    updateSendStats(conv);

                }

            }, "WorkingMessage.send SMS").start();

        }



        // update the Recipient cache with the new to address, if it's different

        RecipientIdCache.updateNumbers(conv.getThreadId(), conv.getRecipients());



        // Mark the message as discarded because it is "off the market" after being sent.

        mDiscarded = true;

    }

通过对上述代码<TAG 1-3>的方法分析发现，将<TAG 1-3>进行如下修改，问题得到解决。

    public void setSubject(CharSequence s, boolean notify) {<TAG 1-3 MOD>

        mSubject = s;

        if (mSlideshow != null) {

  updateState(HAS_SUBJECT, (s != null), false);

            mSlideshow.setSubjectSize((s == null) ? 0 : s.toString().getBytes().length);

        }else

        updateState(HAS_SUBJECT, (s != null), notify);

}

这里的解决思路为：根据当前幻灯片对象是否为空来判断是否有必要更新状态。