我正在使用此处找到的代码： https://github.com/codepath/android_guides/wiki/Basic-Painting-with-Views
我已经复制并粘贴了活动xml文件和java文件中的所有内容。当我尝试运行它时，应用程序立即崩溃。
<_>在activity_simple_drawing_view.xml中 第6行：工具：context =“。MainActivity”＆gt; .MainActivity是红色的，这让我觉得作者忘了在教程中包含一个主要的活动。android monitor：
06-24 14:41:29.140 1981-1981/? I/art: Late-enabling -Xcheck:jni
[ 06-24 14:41:29.140 135: 375 I/ ]
HWComposer -> eventControl
06-24 14:41:29.451 1981-1981/com.codepath.example.simpledrawapp D/ActivityThread: installProvider: context.getPackageName()=com.codepath.example.simpledrawapp
06-24 14:41:29.457 1981-1981/com.codepath.example.simpledrawapp I/InstantRun: starting instant run server: is main process
06-24 14:41:29.462 1981-1981/com.codepath.example.simpledrawapp D/ActivityThread: BIND_APPLICATION handled : 0 / AppBindData{appInfo=ApplicationInfo{191fcf34 com.codepath.example.simpledrawapp}}
06-24 14:41:29.465 1981-1981/com.codepath.example.simpledrawapp D/AndroidRuntime: Shutting down VM
06-24 14:41:29.466 1981-1981/com.codepath.example.simpledrawapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.codepath.example.simpledrawapp, PID: 1981
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.codepath.example.simpledrawapp/com.codepath.example.simpledrawapp.SimpleDrawingView}: java.lang.InstantiationException: class com.codepath.example.simpledrawapp.SimpleDrawingView has no zero argument constructor
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2366)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2519)
at android.app.ActivityThread.access$800(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:189)
at android.app.ActivityThread.main(ActivityThread.java:5532)
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:950)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)
Caused by: java.lang.InstantiationException: class com.codepath.example.simpledrawapp.SimpleDrawingView has no zero argument constructor
at java.lang.Class.newInstance(Class.java:1563)
at android.app.Instrumentation.newActivity(Instrumentation.java:1065)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2356)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2519)
at android.app.ActivityThread.access$800(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:189)
at android.app.ActivityThread.main(ActivityThread.java:5532)
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:950)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)
Caused by: java.lang.NoSuchMethodException: <init> []
at java.lang.Class.getConstructor(Class.java:531)
at java.lang.Class.getDeclaredConstructor(Class.java:510)
at java.lang.Class.newInstance(Class.java:1561)
at android.app.Instrumentation.newActivity(Instrumentation.java:1065)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2356)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2519)
at android.app.ActivityThread.access$800(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:189)
at android.app.ActivityThread.main(ActivityThread.java:5532)
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:950)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)
06-24 14:41:46.418 1981-1981/? I/Process: Sending signal. PID: 1981 SIG: 9