android - 如何避免android View 膨胀异常？

Question

我创建了一个扩展表面 View 的类，并也在 XML 中声明。但在执行时抛出错误

这是我的 XML 声明

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.canvassurfaceview.MainActivity" >    
        <com.example.canvasballsmoving.surfaceviewclass
        android:id="@+id/surfaceView_mine"
        android:layout_width="fill_parent"
        android:layout_height="100dp"
        android:layout_marginTop="20dp" />  
</RelativeLayout>

这是主要 Activity

> public class MainActivity extends Activity {
> 
>     @Override
>     protected void onCreate(Bundle savedInstanceState) 
>     {
>         super.onCreate(savedInstanceState);
>         setContentView(R.layout.activity_main);
>         //setContentView( new CanvasSurfaceView(this));
>     } 

}

这就是类(class)

public class surfaceviewclass extends SurfaceView implements SurfaceHolder.Callback
{

    private static final String TAG = "NEW";

    public surfaceviewclass(Context context) 
    {
        super(context);
        Log.e ( TAG, " Surfacevie class constructor called ");
        getHolder().addCallback(this);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder)
    {
         Log.e ( TAG, "MY surface is created ");
        // TODO Auto-generated method stub
            Log.e ( TAG, " Height of new surface "+         getHeight());
            Log.e ( TAG, " widthof new surface  "+          getWidth());

    }
/* All overrided functions */

}

这是错误

09-28 21:12:31.169: W/dalvikvm(1975): threadid=1: thread exiting with uncaught exception (group=0x40018578)
09-28 21:12:31.179: E/AndroidRuntime(1975): FATAL EXCEPTION: main
09-28 21:12:31.179: E/AndroidRuntime(1975): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.canvasballsmoving/com.example.canvasballsmoving.MainActivity}: android.view.InflateException: Binary XML file line #11: Error inflating class com.example.canvasballsmoving.surfaceviewclass
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.os.Looper.loop(Looper.java:130)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread.main(ActivityThread.java:3687)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at java.lang.reflect.Method.invokeNative(Native Method)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at java.lang.reflect.Method.invoke(Method.java:507)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at dalvik.system.NativeStart.main(Native Method)
09-28 21:12:31.179: E/AndroidRuntime(1975): Caused by: android.view.InflateException: Binary XML file line #11: Error inflating class com.example.canvasballsmoving.surfaceviewclass
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.createView(LayoutInflater.java:508)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:209)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.Activity.setContentView(Activity.java:1657)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at com.example.canvasballsmoving.MainActivity.onCreate(MainActivity.java:24)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
09-28 21:12:31.179: E/AndroidRuntime(1975):     ... 11 more
09-28 21:12:31.179: E/AndroidRuntime(1975): Caused by: java.lang.NoSuchMethodException: surfaceviewclass(Context,AttributeSet)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at java.lang.Class.getMatchingConstructor(Class.java:643)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at java.lang.Class.getConstructor(Class.java:472)
09-28 21:12:31.179: E/AndroidRuntime(1975):     at android.view.LayoutInflater.createView(LayoutInflater.java:480)
09-28 21:12:31.179: E/AndroidRuntime(1975):     ... 21 more

非常感谢您的建议

Answer 1

你错过了一个构造函数，

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

编辑:

这是从 xml 扩充(构造) View 时调用的构造函数。您声明的属性由第二个参数提供