Android编程出现Button点击事件无效的解决方法示例

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:gravity="center_vertical" >
  <LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="<span style="font-family: Arial, Helvetica, sans-serif;">fill_parent</span><span style="font-family: Arial, Helvetica, sans-serif;">"</span>
    android:orientation="horizontal" >
    <Button
      android:id="@+id/canshusback"
      android:layout_width="25dp"
      android:layout_height="25dp"
      android:layout_marginLeft="5dp"
      android:layout_marginTop="5dp"
      android:background="@drawable/last" />
  </LinearLayout>
  <ScrollView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <RelativeLayout
      android:id="@+id/allti"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center_vertical" >