昨天升級了Xcode8beta版，興高采烈的打開工程啓動模擬器後發現自己的NSLog輸出在console中看不到了，查閱Xcode8 release note後發現官方的中有這麼一段
When debugging an app running on Simulator, logs may not be visible in the console.
Workaround: Use command + / in Simulator.app to open the system log in the Console app to view NSLogs. (26457535)
那麼官方的方案是推薦我們使用系統的控制檯來看日誌：開着模擬器，按下“Command”和“/”鍵調出來，混雜着各種亂七八糟的日誌，閱讀起來很不爽。。。
有沒有辦法恢復以前console中顯示我們日誌呢？
好消息是printf()函數經過測試還是可以用的，那麼我們可以通過宏定義來替換原來的NSLog
<code class="hljs lasso has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">#define</span> NSLog(<span class="hljs-attribute" style="box-sizing: border-box;">...</span>) printf(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%f %s\n"</span>,<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">[</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">[</span>NSDate <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">date</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">]</span><span class="hljs-markup" style="box-sizing: border-box;">timeIntervalSince1970],</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">[</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">[</span>NSString stringWithFormat:__VA_ARGS__<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">]</span><span class="hljs-markup" style="box-sizing: border-box;">UTF8String]);</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
如果希望該修改僅針對開發模式生效，可以添加
<code class="hljs vala has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#ifndef __OPTIMIZE__</span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#define NSLog(...) printf("%f %s\n",[[NSDate date]timeIntervalSince1970],[[NSString stringWithFormat:__VA_ARGS__]UTF8String]);</span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#endif</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
好了，把這個宏丟到你的項目中比如Debug.h文件中，在全局引用中或各個文件自己引用即可