mauricio's questions

You will see what I want is to call the variable of my provider, which in this case is:

Icon _hearticon = const Icon(
    Icons.favorite_border,
  );

and also the method that changes the shape of the icon when pressed.

void changeHeart() {
    if (_hearticon.icon == Icons.favorite_border) {
      _hearticon = const Icon(
        Icons.favorite,
      );
    } else {
      _hearticon = const Icon(
        Icons.favorite_border,
      );
    }
    notifyListeners();
  }

here the complete provider

import 'package:flutter/material.dart';

class HeartIconState with ChangeNotifier {
  Icon _hearticon = const Icon(
    Icons.favorite_border,
  );
  void changeHeart() {
    if (_hearticon.icon == Icons.favorite_border) {
      _hearticon = const Icon(
        Icons.favorite,
      );
    } else {
      _hearticon = const Icon(
        Icons.favorite_border,
      );
    }
    notifyListeners();
  }

  Icon get hearticon => _hearticon;

  set hearticon(Icon value) {
    _hearticon = value;
    notifyListeners();
  }
}

and the way I'm calling them:

IconButton(
   icon: Heart.hearticon,
   color: Colors.red,
   iconSize: 25.0,
  onPressed: Heart.changeHeart,
           ),

I had already done it like this when I was manipulating the state of a color to change from black to white and vice versa. I add the errors here. I uploaded a photograph because there are many.

I work with this api https://api.jikan.moe/v4/anime , what I don't know is how to show it inside my app.

as it appears in the api ("url": "https://www.youtube.com/watch?v=bJVyIXeUznY",) at first I tried to show it inside a text widget, then I realized that it didn't make sense.

   Text(
    widget.recibirdatos.urlyoutube ?? 'no hay url',
           style: const TextStyle(
           fontSize: 20, color: Colors.black),
Text),

I am displaying images as a response from an API inside a Gridview.builder, when I wrap it inside a center everything works fine.

the problem arises when what I want is to add a sizebox to move the gridview away from the appbar and put content in between them. the center only has child so I can't put more elements. but I want to replace it with a listview or a column that receives childrens. and it does not throw me any error by console. the app just goes blank.

gridview code

Widget build(BuildContext context) {
    return FutureBuilder<List<Dogdata>>(
      future: fetchDogdata(),
      builder: (BuildContext context, AsyncSnapshot<List<Dogdata>> snapshot) {
        if (snapshot.hasData) {
          final lista = snapshot.data!;
          return GridView.builder(
            shrinkWrap: true,
            gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
              crossAxisCount: 2,
              crossAxisSpacing: 10.0,
              mainAxisSpacing: 10.0,
              
            ),
            itemCount: lista.length,
            itemBuilder: (BuildContext context, int index) {
              return Container(
                decoration: BoxDecoration(
                  //border: Border.all(),
                  borderRadius: BorderRadius.circular(20),
                  shape: BoxShape.rectangle,

                ),
                child: Image.network(
                  lista[index].imagen,
                  fit: BoxFit.cover,
                  width: double.infinity,
                  height: double.infinity,
                ),
              );
            },
          );
        } else {
          return const CircularProgressIndicator();
        }
      },
    );
  }
}

and the main screen that when putting the column or listview gives an error.

body: Center(
          child: Column(
            children: [
              Api(),
            ],
          )),

I am relying on the flutter documentation for this api call. but I am not rendering the images from the url on the screen, it keeps loading infinitely.

 import 'package:apidog/models/dogdata.dart';
import 'package:flutter/material.dart';
// ignore: unused_import
import 'package:http/http.dart' as http;
import 'dart:convert';

class Api extends StatefulWidget {
  //se convierte en un objeto dart
  Future<Dogdata> fetchDogdata() async {
    final response =
        await http.get(Uri.parse('https://dog.ceo/api/breed/hound/images'));

    if (response.statusCode == 200) {
      // If the server did return a 200 OK response,
      // then parse the JSON.
      return Dogdata.fromJson(jsonDecode(response.body));
    } else {
      // If the server did not return a 200 OK response,
      // then throw an exception.
      throw Exception('Failed to load album');
    }
  }

  //Api({Key? key}) : super(key: key);

  @override
  State<Api> createState() => _ApiState();
}

class _ApiState extends State<Api> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: FutureBuilder(
          future: widget.fetchDogdata(),
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.hasData) {
              final lista = (snapshot.data["message"] as List);
              return ListView.builder(
                itemCount: lista.length,
                itemBuilder: (BuildContext context, int index) {
                  return Image.network(lista[index]);
                },
              );
            } else {
              return CircularProgressIndicator();
            }
          },
        ),
      ),
    );
  }
}

here the external code of the model.

class Dogdata {
  final String imagen;

  const Dogdata({
    required this.imagen,
  });

//crea un archivo json
  factory Dogdata.fromJson(Map<String, dynamic> json) {
    return Dogdata(
      imagen: json['message'],
    );
  }
}

This is the api where I want to fetch the images. I copied that url in the request part and when trying to render them on the screen it tells me that it expected a string but it found a dynamic list. I tried a tostring() but I really don't know.

    import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';

class Api extends StatefulWidget {
  var url = Uri.parse("https://dog.ceo/api/breed/hound/images");

  Future<dynamic> getdogs() async {
    final respuesta = await http.get(url);

    if (respuesta.statusCode == 200) {
      //print(jsonDecode(respuesta.body));
      return (jsonDecode(respuesta.body));
    } else {
      print("Error con la respusta");
    }
  }

  //Api({Key? key}) : super(key: key);

  @override
  State<Api> createState() => _ApiState();
}

class _ApiState extends State<Api> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: FutureBuilder(
          future: widget.getdogs(),
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.hasData) {
              return Column(
                children: [
                  Image.network(snapshot.data["message"]
                  ),
                  //Text("${snapshot.data["status"]}"),
                ],
              );
              
            } else {
              return CircularProgressIndicator();
            }
          },
        ),
      ),
    );
  }
}

When compiling my app, this warning appears inside the container. I've been told to use the expanded widget by wrapping the container and it doesn't work.

 return Container(
  width: 500.0,
  height: 600.0,
  margin: const EdgeInsets.symmetric(horizontal: 5.0),
  decoration: BoxDecoration(
    borderRadius: const BorderRadius.all(Radius.circular(8.0)),
    color: color,
    boxShadow: const [
      BoxShadow(
        color: Colors.black,
        blurRadius: 0.0,
        spreadRadius: 0.0,
        offset: Offset(0.0, 0.0), // shadow direction: bottom right
      )
    ],
  ),
  child: Container(
    margin: const EdgeInsets.symmetric(horizontal: 15.0, vertical: 20.0),
    child: Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Container(
          margin: const EdgeInsets.only(top: 11.0),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Image.asset(
                logo,
                width: 50,
                height: 50,
              ),
              const Icon(Icons.favorite, color: Colors.red),
            ],
          ),
        ),
        const SizedBox(
          height: 10,
        ),
        Text(
          companyname,
          style: const TextStyle(
              fontSize: 12,
              fontWeight: FontWeight.bold,
              color: Colors.white),
        ),
        Text(
          role,
          style: const TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.bold,
              color: Colors.white),
        ),
        Row(
          mainAxisAlignment: MainAxisAlignment.start,
          children: [
            const Icon(
              Icons.location_on,
              color: Colors.white,
              size: 15,
            ),
            Text(
              region,
              style: const TextStyle(
                  fontSize: 12,
                  fontWeight: FontWeight.bold,
                  color: Colors.white),
            ),
          ],
        ),
      ],
    ),
  ),
);

} }

I'm new to sql, the strange thing is that I use the alter table command to create a column called "height" when I insert his height look what happened.

It is a lack of control that alter table only creates columns with null and when inserting data they run.

I am trying to connect my app to firebase and when I get to the fourth step,(here is the link) https://console.firebase.google.com/u/0/project/delete123-30fd2/overview

It keeps loading infinitely, I check the Logcat part and find this error.

E/ActivityThread: Failed to find provider info for com.google.android.gms.phenotype

I've been with this error for days, could you please help me.

When I am going to execute the script (in this case with c# mono version) and I get this error (the one in the title) it doesn't even compile to tell me if I have errors or anything. this was the only thing i found

C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(1177,5): error MSB3644: No se encuentran los ensamblados de referencia para .NETFramework,Version=v4.7. Para resolver este problema, instale el Paquete de desarrollador (SDK o Paquete de compatibilidad) de esta versión de .NET Framework o redestine la aplicación. Para descargar los paquetes de desarrollador de .NET Framework, vaya a https://aka.ms/msbuild/developerpacks [E:\Proyectogodot\tutorial\tutorial.csproj]

I have an array of classes, in this case ProductsA. I am going through it with the for each,

Products []productsA = new Products[3];
productsA[0] = new Products("perfum",50);
productsA[1] = new Perishable("tv",400,2);
productsA[2] = new Nonperishable("phone",
            200,"electrodomestico");

for(Products i:productsA) {
        int totalPrice = i.getPrice()*5;
        array = {totalPrice};

that last line marks an error (Array constants can only be initializers). I want that in each return to save that result in the array to later add it and go through it. By the way, I have it globally.

int array[];

also try with the normal for loop and mark more errors I could only with this

Hello, I want to do this procedure but I don't know how. this is python:

num = 7
for i in range(1,num+1):
numbers = []
numbers.append(i)

for x in numbers:

    print(x,end = " ")

here the code in java but it doesn't work for me

int num = 5;
    for(int i = 0; i < num; i++) {
        int array[] = {};
        array.append[i]

As you can see, I can't fill that array like I did with python.

I want to convert this int variable to string.

number = int(input("type one number :"))
parseo = number.ToString();

to later convert that "parse" variable into a list like this.

lista = list(parseo)

I do it because I can't convert a data int to a list directly.

here the error.

AttributeError: 'int' object has no attribute 'ToString'

I don't know the syntax for python.

I'm doing OOP exercises with python and checking code I found this zip()

class pedido:
def __init__(self,productos,cantidades):
    self.__productos = productos
    self.__cantidades = cantidades

def total_pedido(self):
    total = 0

    for(p,c) in zip(self.__productos,self.__cantidades):
        total = total + p.calcular_Total(c) 

here the method that shows the data

def mostrar_pedido(self):
    for(p,c) in zip(self.__productos,self.__cantidades):
        print("producto",p.nombre,"cantidad"+str(c))"""

I wanted to do it like in java but Python doesn't have do while, so I came up with a function:

class trys:

    def menu():
      print("welcome to your soccer team")
      print("1 team trip")
      print("2 training")
      print("3 football game")
      print("4 plan training")
      print("5 interview")
      print("6 heal lesson")

    menu()

the method:

    def method(self):
        option = int(input("type your option :"))
        while option <0 or option >6:
          menu()

p = trys()
p.method() 

I want the function to be called if the user types a different number than the ones on the screen so I don't have to paste the code again. but I get this:

NameError: name 'menu' is not defined

I have a class that is inheriting from another:

class business2(business):
  steps()

The business class has a method from which I want to inherit all that procedure so as not to write the same thing again.

def steps(self):
    i = 0
    while i < self.quantityY:
        years = int(input("year :"))
        sales = int(input(str(years)
            +" sales value :"))
        #we create a list without discount
        self.allyears.append(years)
        self.witOdiscounts.append(sales)

        i+=1
        if i == self.quantityY:
            for x in self.witOdiscounts:
                print(x)

When I run I get this:

steps()
NameError: name 'steps' is not defined

The instance of course:

from exercise6 import *

instance = business2(2)
instance.steps()

What I want is to reuse that method to add more stuff to it and not have to copy and paste it.

I want to multiply these values.

int result,quantity = 10;
double quantity_col = 3.500;
result = quantity*quantity_col;

but the eclipse ide underlines it and gives me an error.

java.lang.Error cannot convert from double to int

It happens that when I add an image using Imageview then the app crashes.

as you can see that cross is the imageview, and when compiling it gives this error.

04-06 23:16:12.117 408-453/system_process E/InputDispatcher: channel '53750588 com.example.fruttyappnew/com.example.fruttyappnew.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!

There is also a line that is underlined in blue. I click on it and it points to this line.

setContentView(R.layout.activity_main2__nivel1);

note (I have tried with the images that come in android by default those gray ones, and it works perfectly.)

Here I add the image in xml mode.

<?xml version="1.0" encoding="utf-8"?>

<ImageView
    android:id="@+id/imageView"
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:layout_marginTop="116dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.27"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/adicion" />

This line is the one I always find in the LogCat when I have this error with the images.

04-07 15:39:08.489 1183-1183/com.example.fruttyappnew A/libc: Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1), thread 1183 (le.fruttyappnew)

It happens that I want to print this data on the screen, which is found in the tostring method.

public String tostring() {
    return "the weight is :"+ this.getWeight() +" and my age is :"+ this.getAge();
}

but it prints it this way

ejercicio2.Ejercicio2@15db9742

here the code with the set and get

public class Ejercicio2 {
private int weight;
private int age;

public int getWeight() {
    return weight;
}
public void setWeight(int weight) {
    this.weight = weight;
}
public int getAge() {
    return age;
}
public void setAge(int age) {
    this.age = age;
}

and the main class

public class Usoejercicio2 {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Ejercicio2 ob1 = new Ejercicio2();

    ob1.setAge(21);
    ob1.setWeight(55);

    System.out.println(ob1);

what am I doing wrong? yes please correct me

I want that when the user types a phone number by keyboard it is saved in this variable (number)

number = input(int("digite un numero teléfono :"))

and then return if those numbers that are stored in the variable have more than 9 characters. I did it this way but I couldn't.

if number.len > 9:
  print("introduciste mas de 9 numeros")

I am learning Python I hope they are flexible. I want to check whether multiple inheritance worked or not, so I want this class to dog:

class dog(animal,to_jump):
    def __init__(self,name):
        self.name = name
    print(f"my dog {self.name} is barking and he is {self.var}")

also inherit the method from this:

class to_jump:
    #this is a method
    def jump(self):
        self.var = "jumping"

to check it I want to print what is in the class variable to_jump (self.var) but in another class, I want it to do this printing correctly.

print(f"my dog {self.name} is barking and he is {self.var}")

and it throws me this error.

File "herencia.py", line 18, in __init__
    print(f"my dog {self.name} is barking and he is {self.var}"
AttributeError: 'dog' object has no attribute 'var'

this is the instance of the dog class.

instancia = dog("bruno")