[UIMenuController locationInView:]:发送到实例0x7f41ca0的无法识别的选择器

Question

当长按UIWebView时，我正在显示UIMenuController菜单项以进行单击操作。我有一个关于UIMenuItem的说明。当我单击注释时，我需要将位置坐标存储到数据库中。在我使用UILongPressGesture将坐标值存储到数据库之前。但它正在起作用。为什么 UIMenuItem 操作不起作用？

- (void)note:(id)sender   {
    NSLog(@"Note");

  //  UILongPressGestureRecognizer *sn=(UILongPressGestureRecognizer *)sender;
    xcor = [sender locationInView:wbCont.scrollView].x;
    ycor = [sender locationInView:wbCont.scrollView].y;

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"db.sqlite"];
    NSLog(@"filepath %@",path);

    if (sqlite3_open([path UTF8String], &database) == SQLITE_OK) {

        const char *sql = [[NSString stringWithFormat:@"SELECT xcoor FROM touch where xcoor = '%f' AND ycoor = '%f' AND artt_id='%@'",xcor,ycor,artID] cStringUsingEncoding:NSUTF8StringEncoding];

        NSLog(@"sql is %s",sql);
        BOOL favExist = false;
        sqlite3_stmt *statement, *addStmt;
        if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) == SQLITE_OK) {
            // We "step" through the results - once for each row.
            while (sqlite3_step(statement) == SQLITE_ROW) {

                favExist = true;
            }
        }

        if(!favExist){

            //Changes
            universal_button_tag = arc4random() % 99;
            NSLog(@"Universal Button tag: %d",universal_button_tag);
            const char *sqlInsert = [[NSString stringWithFormat:@"insert into touch (xcoor,ycoor,artt_id,button_tag) values ('%f','%f','%@','%d')", xcor,ycor,artID,universal_button_tag] cStringUsingEncoding:NSUTF8StringEncoding];
            //----
            NSLog(@"sql insert is %s",sqlInsert);

            // [catID release];
            if(sqlite3_prepare_v2(database, sqlInsert, -1, &addStmt, NULL) != SQLITE_OK)
                NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));
            NSLog(@"error is %s",sqlite3_errmsg(database));
            if(SQLITE_DONE != sqlite3_step(addStmt))
                NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));

        }
    }

Answer 1

如果我

理解正确，您使用的是 NSObject 的子类 https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIMenuItem_Class/Reference/MenuItem.html 并且没有方法 locationInView（手势具有该方法），因此您得到了无法识别的选择器