Kotlin- When

NOTE :1) Whenever we have more then on condition that condition use "when" its a enhance version of switch condition

fun main(){

val userType = "admin"

when(userType){

"admin"->{

println("You'r admin")

}

"editor"->{

println("You'r editor")

}

"author"->{

println("You'r author")

}

else->{

println("You'r Other")

}

}

}

Output: You'r admin

Kotlin - Null Safty

 note : 1) Bydefault All variable non-null 

   2) For Accecpting this null value we have to put '?' with string. 

   3) If variable is null and want to access the properties of variable in that case use 'varible?.' 

   4) if confirm varible is not null then we can use '!!' but if not sure dont use it trow null pointer exception.

var name:String? = null

val Lname:String = "Nishad"

firstname

println("Hello${name?.length}")

Kotlin First Program 'Hello word'

1. Kotlin code is usually defined in packages. Package specification is optional: If you don't specify a package in a source file, its content goes to the default package.
2. An entry point to a Kotlin application is the main function. Since Kotlin 1.3, you can declare main without any parameters. The return type is not specified, which means that the function returns nothing.
3. println writes a line to the standard output. It is imported implicitly. Also note that semicolons are optional.

Example:

val name:String="Kamal"

val Lname:String="Nishad"

fun main(){

println("Hello $name $Lname")

}

OUTPUT: Hello Kamal Nishad

React Native Login Screen

import React, { Component } from 'react';

import { StyleSheet,Text, View, TextInput, Button ,TouchableOpacity} from 'react-native';

import { Image } from 'react-native';

export default class Bananas extends Component {

  render() {

    let pic = {

      uri: 'http://3.6.64.197/pluginfile.php?file=%2F1%2Ftheme_lambda%2Flogo%2F1584095532%2Fcoco.jpg'

    };

    return (   

        <View>

              <Image source={pic} style={{width: 140, height: 50,marginTop:100,alignContent:"center",alignItems:"center",alignSelf:"center"}}/>

              <View>

                  <Text style={style.logo}>Login</Text>

              </View>

              <View>

                  <TextInput style={style.inputView}

                              placeholder="Username" 

                              placeholderTextColor="#000">

                  </TextInput>

              </View>

              <View>

                  <TextInput style={style.inputView}

                              secureTextEntry

                              placeholder="Password"

                              placeholderTextColor="#000"

                              onChangeText={text => this.setState({password:text})}>

                  </TextInput>

              </View>

              <View>

              <TouchableOpacity style={style.loginBtn}>

                  <Text style={style.loginText}>LOGIN</Text>

              </TouchableOpacity>

              </View>

        </View>

    );

  }

}

const style = StyleSheet.create({

  logo:{

    fontWeight:"bold",

    fontSize:20,

    alignSelf:"center",

    color:"#fb5b5a",

    marginTop:50,

  },

  inputView:{

    alignSelf:"center",

    width:"80%",

    backgroundColor:"#C0C0C0",

    borderRadius:5,

    height:50,

    marginTop:10,

    color:"#000",

    marginBottom:20,

    justifyContent:"center",

    padding:10

  },

  loginBtn:{

    width:"80%",

    backgroundColor:"#fb5b5a",

    borderRadius:5,

    height:50,

    alignSelf:"center",

    alignItems:"center",

    justifyContent:"center",

    marginTop:10,

    marginBottom:10

  },

  loginText:{

    color:"white"

  },

  inputIcon:{

    width:30,

    height:30,

    marginLeft:15,

    justifyContent: 'center'

  },

});

Xamarin Emulator Black Screen Problem

Hello,

            My another  blog is there, so today we are discussion about xamarin black screen problem. When I am a beginner that kinds of problems i am also faced. After searching the solution of an problem I get some solution which'r we discussion here so lets start now..


  >> Our Problem...

Step.1) Create a new project.

Step.2) Here the MainActivity where the actual solution this problem.

Step.3) Here is the actual problem. Now remove SetContentView from comment section. 

Step.4) Now Deploy the project.

Here Finally the problem is solved now run project efficiently.

If you Like my blogs please comment below.😉

Intent Activity in xamarin.

✋
Hello Friends,

                 I am kamal and today I will show you about xamarin programming. Its my first blog today hope Its helpfull for you.


😊k Today we are know about intent activity in xamarin.which is very helpful for all the dovelopers lets start.

Step:1)  We need to make a new  android project.

Step:2) There is a MainActivity. which having OnCreate bundle....

Step:3) We need to make a new activity for intent procedure.Create a new activity which is called MainActivity2.

Step:4) We have a resource folder which having Resource->layout->Main.xml
click.and code for simple a button if you don't know about that you can simply drag and drop also.

Step:6) Now go through MainActivity.cs and code for Activity2.

Step:7) Now Deploy MainActivity.cs. 

Step:8) Finally the out is...........

      Thanks for being here If you like plaese comment.it will helpful for us.