android - 在 Eclipse 设计器中投射异常

Question

如何解决将自定义视图放置在另一个中时我在 Eclipse 设计器中遇到的异常。

java.lang.ClassCastException: com.fitness.app.Stopper cannot be cast to android.widget.Button at com.fitness.app.Stopper.<init>(Stopper.java:25).

com.fitness.app.Stopper XML：

<merge xmlns:android="http://schemas.android.com/apk/res/android" >

<Button
    android:id="@+id/btnStartStopper"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginTop="25dp"
    android:text="Start" 
    />

<Chronometer
    android:id="@+id/chronometer1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@+id/btnStartStopper"
    android:layout_marginLeft="18dp"
    android:layout_toRightOf="@+id/btnStartStopper"
    android:text="Chronometer"
    android:textSize="45sp" />

</merge>

和 com.fitness.app.Stopper 第 25 行来自错误： Button btnStart = (Button) findViewById(R.id.btnStartStopper);

    public class Stopper extends LinearLayout {

private Chronometer stopper;
private boolean stopper_started = false;

public Stopper(Context context)
{
    super(context);
}

public Stopper(Context context, AttributeSet attrs) {
    super(context, attrs);
    initializeLayoutBasics(context);        
    this.stopper = (Chronometer) findViewById(R.id.chronometer1);
    Button btnStart = (Button) findViewById(R.id.btnStartStopper);
    btnStart.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            startOrStopStopper(arg0);
        }
    });
}

private void initializeLayoutBasics(Context context) {
    setOrientation(HORIZONTAL);
    final LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    inflater.inflate(R.layout.fragment_stopper, this, true);//TODO change name fragment to different
}

public void startOrStopStopper(View v)
{
    if(!stopper_started)
        stopper.start();
    else
        stopper.stop();

    stopper_started = !stopper_started;
}

}