将click Listener设置为markushi/android圆形按钮

我想将单击侦听器设置为

我使用的是Android Studio 1.1.0，应用程序运行，但在模拟器和Nexus 5（使用API 21）上都会引发异常和崩溃

你知道这是什么原因吗

按钮位于一个框架内，整个屏幕是一个片段

活动\u main.xml:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container"
android:layout_width="match_parent" android:layout_height="match_parent"
tools:context=".MainActivity" tools:ignore="MergeRootFrame"    />

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity$PlaceholderFragment"
android:id="@+id/fra">

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/infoButton"
    android:clickable="true"
    android:src="@drawable/info_button_image"
    android:contentDescription="@string/desc"
    android:adjustViewBounds="false"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<Chronometer
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/chronometer1"
    android:layout_alignBottom="@+id/infoButton"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true">

    </Chronometer>


<FrameLayout
    android:layout_width="90dp"
    android:layout_height="84dp"
    android:id="@+id/start_timing_frame"
    android:layout_gravity="center_horizontal|top"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true">

    <at.markushi.ui.CircleButton
        android:layout_width="90dp"
        android:layout_height="84dp"
        android:clickable="true"
        app:cb_color="#ff99cc00"
        app:cb_pressedRingWidth="5dip"
        android:id="@+id/circleButton"
        android:layout_gravity="right|top"
        android:layout_alignBottom="@+id/infoButton"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <TextView
        android:layout_width="90dp"
        android:layout_height="45dp"
        android:text="@string/start_timing"
        android:id="@+id/startTimingTextView"
        android:layout_gravity="center"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
</FrameLayout>

java.lang.RuntimeException: Unable to start activity ComponentInfo{MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void at.markushi.ui.CircleButton.setOnClickListener(android.view.View$OnClickListener)' 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$MethodAndArgsCaller.run(ZygoteInit.java:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void at.markushi.ui.CircleButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at MainActivity.onCreate(MainActivity.java:39)
        at android.app.Activity.performCreate(Activity.java:5933)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)

}

日志猫：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container"
android:layout_width="match_parent" android:layout_height="match_parent"
tools:context=".MainActivity" tools:ignore="MergeRootFrame"    />

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity$PlaceholderFragment"
android:id="@+id/fra">

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/infoButton"
    android:clickable="true"
    android:src="@drawable/info_button_image"
    android:contentDescription="@string/desc"
    android:adjustViewBounds="false"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<Chronometer
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/chronometer1"
    android:layout_alignBottom="@+id/infoButton"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true">

    </Chronometer>


<FrameLayout
    android:layout_width="90dp"
    android:layout_height="84dp"
    android:id="@+id/start_timing_frame"
    android:layout_gravity="center_horizontal|top"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true">

    <at.markushi.ui.CircleButton
        android:layout_width="90dp"
        android:layout_height="84dp"
        android:clickable="true"
        app:cb_color="#ff99cc00"
        app:cb_pressedRingWidth="5dip"
        android:id="@+id/circleButton"
        android:layout_gravity="right|top"
        android:layout_alignBottom="@+id/infoButton"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <TextView
        android:layout_width="90dp"
        android:layout_height="45dp"
        android:text="@string/start_timing"
        android:id="@+id/startTimingTextView"
        android:layout_gravity="center"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
</FrameLayout>

java.lang.RuntimeException: Unable to start activity ComponentInfo{MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void at.markushi.ui.CircleButton.setOnClickListener(android.view.View$OnClickListener)' 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$MethodAndArgsCaller.run(ZygoteInit.java:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void at.markushi.ui.CircleButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at MainActivity.onCreate(MainActivity.java:39)
        at android.app.Activity.performCreate(Activity.java:5933)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)

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您的按钮位于一个片段中，因此当您尝试findById（…）时，将得到空指针。碎片不是在这一刻产生的

试一试

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在onCreateView（）中

谢谢，对我来说非常有效！尽管我需要删除rootView才能让它为我工作。