Android 自定义控件时出现: Caused by: java.lang.NoSuchMethodException

Caused by: android.view.InflateException: Binary XML file line #20: Error inflating class sourceforge.titlelan.VisualizerView
at android.view.LayoutInflater.createView(LayoutInflater.java:606)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:699)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:758)
at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
at android.view.LayoutInflater.inflate(LayoutInflater.java:400)
at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
at android.app.Activity.setContentView(Activity.java:1943)
at sourceforge.titlelan.MainActivity.onCreate(MainActivity.java:31)
at android.app.Activity.performCreate(Activity.java:5245)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2164)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2249)
at android.app.ActivityThread.access$800(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1212)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5052)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NoSuchMethodException: <init> [class android.content.Context, interface android.util.AttributeSet]
at java.lang.Class.getConstructorOrMethod(Class.java:472)
at java.lang.Class.getConstructor(Class.java:446)
at android.view.LayoutInflater.createView(LayoutInflater.java:571)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:699)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:758)
at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
at android.view.LayoutInflater.inflate(LayoutInflater.java:400)
at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
at android.app.Activity.setContentView(Activity.java:1943)
at sourceforge.titlelan.MainActivity.onCreate(MainActivity.java:31)
at android.app.Activity.performCreate(Activity.java:5245)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2164)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2249)
at android.app.ActivityThread.access$800(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1212)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5052)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
at dalvik.system.NativeStart.main(Native Method)

public VisualizerView(Context context) {
super(context);
init();
}

public VisualizerView(Context context) {
this(context, null);
}

public VisualizerView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}