Crear una aplicación en Android Studio que crea un código QR | Operating systems, scripting, PowerShell and security

Android

Contenidos

Asegúrate de tener las dependencias necesarias en tu archivo build.gradle
MainActivity.kt

Asegúrate de tener las dependencias necesarias en tu archivo build.gradle

implementation("com.google.zxing:core:3.4.1")

1	implementation("com.google.zxing:core:3.4.1")

MainActivity.kt

package com.example.myapplication

import android.graphics.Bitmap
import android.graphics.Color
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.Image
import androidx.compose.foundation.layout.*
import androidx.compose.material3.Button
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.Text
import androidx.compose.material3.TextField
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.asImageBitmap
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.google.zxing.BarcodeFormat
import com.google.zxing.WriterException
import com.google.zxing.common.BitMatrix
import com.google.zxing.qrcode.QRCodeWriter
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyApp()
        }
    }
}

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun MyApp() {
    val context = LocalContext.current
    var text by remember { mutableStateOf("") }
    var bitmap by remember { mutableStateOf<Bitmap?>(null) }
    val coroutineScope = rememberCoroutineScope()

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp),
        verticalArrangement = Arrangement.Center,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        TextField(
            value = text,
            onValueChange = { text = it },
            label = { Text("Enter text for QR code") },
            modifier = Modifier.fillMaxWidth()
        )

        Spacer(modifier = Modifier.height(16.dp))

        DisposableEffect(Unit) {
            onDispose {
                bitmap = null // Limpiamos el bitmap existente
            }
        }

        Button(
            onClick = {
                if (text.isNotEmpty()) {
                    bitmap = null // Limpiamos el bitmap existente
                    coroutineScope.launch {
                        val generatedBitmap = generateQRCode(context, text)
                        bitmap = generatedBitmap
                    }
                }
            }
        ) {
            Text("Generate QR Code")
        }

        Spacer(modifier = Modifier.height(16.dp))

        if (bitmap != null) {
            Image(
                bitmap = bitmap!!.asImageBitmap(),
                contentDescription = "QR Code",
                modifier = Modifier.size(200.dp),
                contentScale = ContentScale.Fit
            )
        }
    }
}

suspend fun generateQRCode(
    context: android.content.Context,
    text: String
): Bitmap? {
    return withContext(Dispatchers.Default) {
        val qrCodeWriter = QRCodeWriter()
        try {
            val bitMatrix: BitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, 512, 512)
            val width: Int = bitMatrix.width
            val height: Int = bitMatrix.height
            val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565)
            for (x in 0 until width) {
                for (y in 0 until height) {
                    bitmap.setPixel(
                        x,
                        y,
                        if (bitMatrix[x, y]) Color.BLACK else Color.WHITE
                    )
                }
            }
            bitmap
        } catch (e: WriterException) {
            e.printStackTrace()
            null
        }
    }
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    MyApp()
}

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package com.example.myapplication

import android.graphics.Bitmap

import android.graphics.Color

import android.os.Bundle

import androidx.activity.ComponentActivity

import androidx.activity.compose.setContent

import androidx.compose.foundation.Image

import androidx.compose.foundation.layout.*

import androidx.compose.material3.Button

import androidx.compose.material3.ExperimentalMaterial3Api

import androidx.compose.material3.Text

import androidx.compose.material3.TextField

import androidx.compose.runtime.*

import androidx.compose.ui.Alignment

import androidx.compose.ui.Modifier

import androidx.compose.ui.graphics.asImageBitmap

import androidx.compose.ui.layout.ContentScale

import androidx.compose.ui.platform.LocalContext

import androidx.compose.ui.tooling.preview.Preview

import androidx.compose.ui.unit.dp

import com.google.zxing.BarcodeFormat

import com.google.zxing.WriterException

import com.google.zxing.common.BitMatrix

import com.google.zxing.qrcode.QRCodeWriter

import kotlinx.coroutines.Dispatchers

import kotlinx.coroutines.launch

import kotlinx.coroutines.withContext

class MainActivity : ComponentActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContent {

MyApp()

}

@OptIn(ExperimentalMaterial3Api::class)

@Composable

fun MyApp() {

val context = LocalContext.current

var text by remember { mutableStateOf("") }

var bitmap by remember { mutableStateOf<Bitmap?>(null) }

val coroutineScope = rememberCoroutineScope()

Column(

modifier = Modifier

.fillMaxSize()

.padding(16.dp),

verticalArrangement = Arrangement.Center,

horizontalAlignment = Alignment.CenterHorizontally

) {

TextField(

value = text,

onValueChange = { text = it },

label = { Text("Enter text for QR code") },

modifier = Modifier.fillMaxWidth()

)

Spacer(modifier = Modifier.height(16.dp))

DisposableEffect(Unit) {

onDispose {

bitmap = null // Limpiamos el bitmap existente

}

Button(

onClick = {

if (text.isNotEmpty()) {

bitmap = null // Limpiamos el bitmap existente

coroutineScope.launch {

val generatedBitmap = generateQRCode(context, text)

bitmap = generatedBitmap

}

) {

Text("Generate QR Code")

}

Spacer(modifier = Modifier.height(16.dp))

if (bitmap != null) {

Image(

bitmap = bitmap!!.asImageBitmap(),

contentDescription = "QR Code",

modifier = Modifier.size(200.dp),

contentScale = ContentScale.Fit

)

}

suspend fun generateQRCode(

context: android.content.Context,

text: String

): Bitmap? {

return withContext(Dispatchers.Default) {

val qrCodeWriter = QRCodeWriter()

try {

val bitMatrix: BitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, 512, 512)

val width: Int = bitMatrix.width

val height: Int = bitMatrix.height

val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565)

for (x in 0 until width) {

for (y in 0 until height) {

bitmap.setPixel(

if (bitMatrix[x, y]) Color.BLACK else Color.WHITE

)

}

bitmap

} catch (e: WriterException) {

e.printStackTrace()

null

}

@Preview(showBackground = true)

@Composable

fun DefaultPreview() {

MyApp()

}

Crear una aplicación en Android Studio que crea un código QR (Android)

Asegúrate de tener las dependencias necesarias en tu archivo build.gradle

MainActivity.kt

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