DraweLayout事件分发兄弟拦截为什么拦截不住而且只能拉出一半

[FlyPanda_若曦]

XML文件
<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.pro.MainActivity"
>

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginRight="46dp"
android:layout_marginTop="66dp"
android:text="Button"
android:onClick="click"/>
<com.example.pro.Layout
android:id="@+id/drawlayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
></FrameLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_gravity="left" >

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
</com.example.pro.Layout>

</RelativeLayout>


自定义DrawerLayout
package com.example.pro;

import android.content.Context;
import android.support.v4.widget.DrawerLayout;
import android.util.AttributeSet;
import android.view.MotionEvent;

public class Layout extends DrawerLayout {
private int gravity;
public Layout(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}

public void setGravity(int g){
gravity =g;
}

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
super.dispatchTouchEvent(ev);
return isDrawerOpen(gravity);
}
}

Main

package com.example.pro;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.GravityCompat;
import android.view.View;


public class MainActivity extends Activity {
Layout lay;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lay=(Layout) findViewById(R.id.drawlayout);
lay.setGravity(GravityCompat.START);
}
public void click(View v) {
lay.setGravity(GravityCompat.START);
}

}