如何在Android中操纵另一个类的视图?
我有一个在单独的类中接收SMS的处理程序。如何使其在执行处理程序时更改视图元素 这是我的密码:如何在Android中操纵另一个类的视图?,android,android-layout,android-view,Android,Android Layout,Android View,我有一个在单独的类中接收SMS的处理程序。如何使其在执行处理程序时更改视图元素 这是我的密码: public class MainActivity extends MapActivity { MapView mapView; MapController mc; GeoPoint p; private int carNumber; private String langt; private String longt; CheckedTextV
public class MainActivity extends MapActivity {
MapView mapView;
MapController mc;
GeoPoint p;
private int carNumber;
private String langt;
private String longt;
CheckedTextView text;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SmsReceiver smsreceiver = new SmsReceiver();
draw();
}
public void draw() {
mapView = (MapView) findViewById(R.id.mapView);
LinearLayout zoomLayout = (LinearLayout) findViewById(R.id.zoom);
@SuppressWarnings("deprecation")
View zoomView = mapView.getZoomControls();
zoomLayout.addView(zoomView, new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
mapView.displayZoomControls(true);
mc = mapView.getController();
double lat = Double.parseDouble("31.977185185185185");
double lng = Double.parseDouble("35.205925925925925");
p = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
mc.animateTo(p);
mc.setZoom(17);
MapOverlay mapOverlay = new MapOverlay();
List<Overlay> listOfOverlays = mapView.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
mapView.invalidate();
}
}
}
我想在SmsReceiver
类中修改MapView
谢谢。将此添加到onReceive()方法中:
定义接口并使用回调让活动知道已收到SMS
public Interface SmsReceivedListener {
void onSmsReceived(int arg1, string arg2); ..<----add arguments you want to pass back
}
在您的活动中:
public class MainActivity extends MapActivity implements SmsReceivedListener {
...
@Override
public void onCreate(Bundle savedInstanceState)
{
...
smsReceiver.setSmsReceivedistener(this);
...
}
public void onSmsReceived(int arg1, string arg2){
// do whatever you need to do
}
所有这些都来自内存,因此请原谅输入错误,您应该通过添加RemoveSMReceiveDistener并检查是否在SetSMReceiveDistener中两次添加相同的侦听器来改进SMS类
注意。因为你使用一个接口,所以任何类(不仅仅是一个活动)都可以实现它,这样你就可以在应用程序中的任何地方进行更新。smsReceiver类不知道也不关心。它只调用已注册的侦听器。试试这个
TextView bt1 =m_activity.findViewById(R.id.textview1);
在上面的示例中,视图bt1来自另一个类。您可以通过使用类实例访问bt1并获取id。现在,对bt1实例执行您想要执行的操作
注意:确保bt1在另一个类中是公共的听起来不错,但我有一个问题,当我第一次传递侦听器时,它不是空的,但是当调用Onreceive处理程序时,侦听器结果是空的,这怎么可能呢?亲爱的Simon,代码在这个链接中
ArrayList<SmsReceivedistener> listeners = new ArrayList<SmsReceivedistener>();
...
public void setSmsReceivedistener(SmsReceivedistenerlistener){
listeners.add(listener);
}
for (SmsReceivedistener listener:listeners){
listener.onSmsReceived(arg1, arg2);
}
public class MainActivity extends MapActivity implements SmsReceivedListener {
...
@Override
public void onCreate(Bundle savedInstanceState)
{
...
smsReceiver.setSmsReceivedistener(this);
...
}
public void onSmsReceived(int arg1, string arg2){
// do whatever you need to do
}
TextView bt1 =m_activity.findViewById(R.id.textview1);