小编Use*_*218的帖子

我的logcat中的错误是这样的

logcat的

08-29 08:20:57.961: ERROR/AndroidRuntime(1766): java.lang.RuntimeException: Unable to start activity ComponentInfo{one.two/one.two.Booking}: java.lang.IllegalArgumentException: column '_id' does not exist
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2268)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2284)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.app.ActivityThread.access$1800(ActivityThread.java:112)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.os.Looper.loop(Looper.java:123)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at android.app.ActivityThread.main(ActivityThread.java:3948)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at java.lang.reflect.Method.invokeNative(Native Method)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at java.lang.reflect.Method.invoke(Method.java:521)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
08-29 08:20:57.961: ERROR/AndroidRuntime(1766):     at dalvik.system.NativeStart.main(Native Method)
08-29 …

嗨,我想让我的地图放大到我当前的位置.当前通过向仿真器发送lat和long来定义当前位置.我该怎么做呢？

我目前的mapactivity.java

public class MapsActivity extends MapActivity {

    private MapView mapView;
    private MyLocationOverlay myLocOverlay;
    MapController mc;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mapactivity);
        initMap();
        initMyLocation();


    }

    /**
     * Initialise the map and adds the zoomcontrols to the LinearLayout.
     */
    private void initMap() {
        mapView = (MapView) findViewById(R.id.mapView);

        View zoomView = mapView.getZoomControls();
        LinearLayout myzoom = (LinearLayout) findViewById(R.id.zoom);
        myzoom.addView(zoomView);
        mapView.displayZoomControls(true);
        mapView.getController().setZoom(17);
    }

    /**
     * Initialises the MyLocationOverlay and adds it to the …

我想用谷歌地图显示我在Android手机上的当前位置.以下代码是否能够在谷歌地图上显示我当前的位置？

MapsActivity.java

package log1.log2;

import log1.log2.MyLocation.LocationResult;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.MapView.LayoutParams;

import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;

public class MapsActivity extends MapActivity 
{    
    MapView mapView; 
    MapController mc;
    GeoPoint p;

    /** Called when the activity is first created. */
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mapactivity);

        mapView = (MapView) findViewById(R.id.mapView);
        LinearLayout zoomLayout = (LinearLayout)findViewById(R.id.zoom);  
        View zoomView = mapView.getZoomControls(); 
        zoomLayout.addView(zoomView, 
            new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, 
                LayoutParams.WRAP_CONTENT)); 
        mapView.displayZoomControls(true);
    }
    MyLocation myLocation = …

logcat的

08-17 06:37:22.264: ERROR/AndroidRuntime(1090): java.lang.RuntimeException: Unable to start activity ComponentInfo{one.two/one.two.Booking}: java.lang.NullPointerException
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2268)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2284)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.app.ActivityThread.access$1800(ActivityThread.java:112)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.os.Looper.loop(Looper.java:123)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at android.app.ActivityThread.main(ActivityThread.java:3948)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at java.lang.reflect.Method.invokeNative(Native Method)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at java.lang.reflect.Method.invoke(Method.java:521)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090):     at dalvik.system.NativeStart.main(Native Method)
08-17 06:37:22.264: ERROR/AndroidRuntime(1090): Caused by: java.lang.NullPointerException
08-17 …

有什么办法可以为我的计时器添加毫秒数吗？

我目前正在使用这个计时器,但它只能在几秒钟内完成.

var count=99;
    var counter=setInterval(timer, 1000); //1000 will  run it every 1 second

    function timer(){
      count=count-1;

      if (count <= 0){
        clearInterval(counter);
        return;
      }
      document.getElementById("timer").innerHTML=count + " seconds"; // watch for spelling
    }

谢谢