Android 为什么我的panel类为null public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.main); _panel=(panel)findviewbyd(R.id.panel); _panel.setOnTouchListener(此); } main.xml
启动应用程序时,在Oncreat()中,我无法从R.id.panel获取_面板,是否缺少任何内容?是否定义了com.android.demo.panel类?是的,我定义了。如果我自己新建面板,则设置ContentView(mypanel)。这样就行了Android 为什么我的panel类为null public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.main); _panel=(panel)findviewbyd(R.id.panel); _panel.setOnTouchListener(此); } main.xml,android,Android,启动应用程序时,在Oncreat()中,我无法从R.id.panel获取_面板,是否缺少任何内容?是否定义了com.android.demo.panel类?是的,我定义了。如果我自己新建面板,则设置ContentView(mypanel)。这样就行了 public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main)
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
_panel = (Panel) findViewById(R.id.panel);
_panel.setOnTouchListener(this);
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/Xiaohua_Demo"
/>
<com.android.demo.Panel
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/panel"
/>
</LinearLayout>