我为表面视图创建了一个 TapGestureDetector 类。在那里我捕捉到了长触摸事件,我想开始一个新的活动。但它不起作用。Intent 没有启动。有一个空指针异常。我已经在清单中定义了动作以及意图。但是有一个我无法识别的错误。
public class TapGestureDetector extends GestureDetector.SimpleOnGestureListener {
int touchX;
int touchY;
public static String block_name;
Context ctx = custom.ctx;
ArrayList<Rect> rectangles = storeMap.GetArrayList();
@Override
public void onLongPress(MotionEvent event) {
//Detect touched X.Y
touchX = (int) event.getX();
touchY = (int) event.getY();
//Go through a set of rectangles and identify the touched rectangle
for (int i = 0; i < rectangles.size(); i++) {
if (rectangles.get(i).contains(touchX, touchY)) {
rectangles.get(i).describeContents();
String Selected_rect = String.valueOf(rectangles.get(i));
Store_Identified_Block.Store(Selected_rect);
getSelectedCoordinates();
//Start a new intent
Intent myIntent = new Intent("android.intent.action.zoomlevel");
myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//This is not working
try {
ctx.startActivity(myIntent);
} catch (Exception e) {
Log.d("onLongPress(MotionEvent event)", e.toString());
e.printStackTrace();
}
break;
}
}
super.onLongPress(event);
}