Question

如何启动活动并从对话框按钮发送值？

这就是我现在所拥有的。尝试了许多变化，但按下按钮时应用程序崩溃：

dialog.setPositiveButton("View Profile", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int which) {
        Intent intent = new Intent();
        intent.setClass(context, Profile.class);
        intent.putExtra("profileID",  "8");            
        startActivity(intent);
        dialog.cancel();
        return;
    } 
});

全班：

public class PlacesItemizedOverlay extends ItemizedOverlay {
    private Context context;
    private ArrayList<OverlayItem> items = new ArrayList<OverlayItem>();
    private Activity aClass;

    public PlacesItemizedOverlay(Context aContext, Drawable marker) {
        super(boundCenterBottom(marker));
        context = aContext;
    }

    public void addOverlayItem(OverlayItem item) {
        items.add(item); 
        populate();
    }

    @Override
    protected OverlayItem createItem(int i) {
        return (OverlayItem) items.get(i);
    }

    @Override
    public int size() {
        return items.size();
    }

    @Override
    protected boolean onTap(int index) {
        aClass = new Activity();
        OverlayItem item = (OverlayItem) items.get(index);
        if(item.getTitle() != null)
            {
            AlertDialog.Builder dialog = new AlertDialog.Builder(context);
            dialog.setTitle(item.getTitle());
            dialog.setPositiveButton("View Profile",
                    new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    Intent intent = new Intent();
                    intent.setClass(context, Profile.class);
                    intent.putExtra("profileID",  "8");            
                    aClass.startActivity(intent);
                    dialog.cancel();
                    return;
                } 
            });
            dialog.show();
        }
        return true;
    }
}

logcat的：

06-24 10:35:31.253: WARN/dalvikvm(30118): threadid=1: thread exiting with uncaught exception (group=0x4001d5a0)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118): FATAL EXCEPTION: main
06-24 10:35:31.283: ERROR/AndroidRuntime(30118): java.lang.NullPointerException
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.Activity.startActivityForResult(Activity.java:2901)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.Activity.startActivity(Activity.java:3007)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.example.android.test.PlacesItemizedOverlay$1.onClick(PlacesItemizedOverlay.java:57)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:159)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.os.Looper.loop(Looper.java:143)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.ActivityThread.main(ActivityThread.java:4196)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at java.lang.reflect.Method.invokeNative(Native Method)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at java.lang.reflect.Method.invoke(Method.java:507)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at dalvik.system.NativeStart.main(Native Method)
06-24 10:35:31.293: WARN/ActivityManager(1344):   Force finishing activity com.example.android.test/.SearchActivity

Answer 1

您是否检查过您已在清单文件中添加了Profile.class，如下所示：

 <activity android:name=".Profile" />

Answer 2

在按钮的onClick上，我相信您需要启动活动并使用新活动设置意图，并在AndroidManifest.xml中引用它

Answer 3

我最终不得不重新构建代码，以下是最终的工作：

AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
builder.setTitle(item.getTitle())
.setCancelable(true)
.setPositiveButton("View Details", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int id) {
        Intent intent = new Intent(mContext, Profile.class);
        intent.putExtra("id", item.getSnippet());
        mContext.startActivity(intent);
        }
    });
AlertDialog alert = builder.create();
alert.show();
return true;

如何从对话框中启动活动？

3 个答案: