小编Pra*_*kar的帖子

我是android的新手,我正在关注Material Design Toolbar的以下教程:

http://www.android4devs.com/2014/12/how-to-make-material-design-app.html

但是在执行代码之后.logcat中显示以下错误:

04-01 19:16:10.214    2246-2253/com.example.bhaskar.ddit_results E/art? Failed sending reply to debugger: Broken pipe
04-01 19:16:11.985    2246-2246/com.example.bhaskar.ddit_results E/AndroidRuntime? FATAL EXCEPTION: main
Process: com.example.bhaskar.ddit_results, PID: 2246
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bhaskar.ddit_results/com.example.bhaskar.ddit_results.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
        at android.app.ActivityThread.access$800(ActivityThread.java:144)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5221)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on …

我是GNU autotools的新手，在我尝试的项目中，./configure它会产生以下错误：

./configure: line 9852: syntax error near unexpected token `luajit,'
./configure: line 9852: `    PKG_CHECK_MODULES(luajit, luajit,LLUAJIT="yes",LLUAJIT="no")'

在Configure.in中：

 PKG_CHECK_MODULES(luajit, luajit,LLUAJIT="yes",LLUAJIT="no")
    if test "x$LLUAJIT" = "xyes"; then
        CONFIGFLAGS="$CONFIGFLAGS -DHAVE_LIBLUAJIT"
        LUA_CFLAGS="$luajit_CFLAGS"
        LUA_LIBS="$luajit_LIBS"
        AC_SUBST(LUA_CFLAGS)
        AC_SUBST(LUA_LIBS)
        if test "x$macos" != "xno"; then
            LDFLAGS="${LDFLAGS} -pagezero_size 10000 -image_base 100000000"
        fi

    else
        echo
        echo "   ERROR!  LuaJIT library not found. For better performance, go get it from"
        echo "   http://www.luajit.org/."
        AC_MSG_ERROR("Fatal!")
    fi

似乎autoconf（也许）无法找到PKG_CHECK_MODULES宏。我在Internet上搜索了解决方案，发现这是因为libtool未安装。重新安装后libtool，错误仍然存​​在。

希望有人认识到问题并迅速解决，希望能得到您的帮助。