解決MainActivity.onCreate(Unknown Source)的混淆錯誤

將D:\Work\FWatch\forwatch\build\outputs\mapping\release\mapping.txt複製到D:\Android\SDK\tools\proguard\bin，
然後將崩潰的crash.log也複製到這個目錄下，用如下命令，可以查看具體的崩潰點：
retrace.bat mapping.txt crash.log

也可以執行如下腳本（auto.bat）：for %%s in (*.log) do retrace mapping.txt %%s > %%s.txt

我寫了個DOS批處理的腳本：retrace.bat，把它丟到crash.log文件夾下，雙擊即可。

@echo off&setlocal enabledelayedexpansion
set RETRACE_PATH=D:\Android\SDK\tools\proguard\bin
set MAPPING_PATH=D:\Work\FWatch\forwatch\build\outputs\mapping\release
set CURRENT_PATH=%cd%
echo RETRACE_PATH: %RETRACE_PATH%
echo MAPPING_PATH: %MAPPING_PATH%
echo CURRENT_PATH: %CURRENT_PATH%

set retrace=retrace.bat
set mapping=%MAPPING_PATH%\mapping.txt
echo retrace: %retrace%
echo mapping: %mapping%

@echo 轉換開始
@for %%s in (*.log) do (
@cd /d %RETRACE_PATH%
retrace %mapping% "%cd%\%%s" > "%cd%\%%s.txt"
@cd /d %cd%
)

pause