Question

我是Android和Kotlin的新手。

任何人都可以帮我在webView

中加载网址

我只是想在应用程序打开时加载URL并查看网页。

Answer 1

1.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.kotlinwebview.MainActivity">


<WebView
    android:id="@+id/webview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:ignore="MissingConstraints"
    tools:layout_editor_absoluteX="8dp"
    tools:layout_editor_absoluteY="8dp" />

2.MainActivity.kt

class MainActivity : AppCompatActivity() {
    var mywebview: WebView? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        mywebview = findViewById<WebView>(R.id.webview)
        mywebview!!.webViewClient = object : WebViewClient() {
            override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
                view?.loadUrl(url)
                return true
            }
        }
        mywebview!!.loadUrl("https://www.google.co.in/")
    }
}

Answer 2

使用Android Kotlin Extension插件。如果您使用的是Android Studio 3.0及更高版本，请不必担心。该项目已安装在您的项目中。

在布局中使用WebView的ID，然后调用loadUrl（）方法。

Android WebView Example - Kotlin & Java

此处是WebView的ID：webview

webview.loadUrl("https://www.androidride.com")

别忘了添加

<uses-permission android:name="android.permission.INTERNET"/>

如果您打开的第三方浏览器使用WebView中加载的任何URL，请提供WebViewClient。

webview.webViewClient = WebViewClient()

如果要在WebView中播放youtube视频，则必须在WebView中启用JavaScript。

webview.settings.javaScriptEnabled = true

如果您是Android应用程序开发的初学者，那么本教程将帮助您清除几乎所有对WebView的疑问。

click here

Answer 3

将此添加到您的活动中：

@SuppressLint("SetJavaScriptEnabled")
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    setContentView(R.layout.activity_webview)

    val mWebView = findViewById<WebView>(R.id.webview)

    val webSettings = mWebView.settings
    webSettings.javaScriptEnabled = true
    mWebView.loadUrl(getString(R.string.website_url))
    mWebView.webViewClient = HelloWebViewClient()
    WebView.setWebContentsDebuggingEnabled(false)

}

并将以下内容添加到HelloWebViewClient()类，以便允许后退按钮导航和出站外部链接：

    override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
        if (Uri.parse(url).host == getString(R.string.website_domain)) {
            return false
        }
        val intent = Intent(Intent.ACTION_VIEW, Uri.parse(url))
        startActivity(intent)
        return true
    }

    override fun onPageFinished(view: WebView, url: String) {
        // TODO Auto-generated method stub
        super.onPageFinished(view, url)
    }

}

override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
    if (keyCode == KeyEvent.KEYCODE_BACK && webview.canGoBack()) {
        webview.goBack()
        return true
    }
    return super.onKeyDown(keyCode, event)
}

添加定义website_domain（https://stackoverflow.com/）和website_host（stackoverflow.com）的字符串。

如果您为了实现目标而遇到困难，请尝试this full sample并按照说明进行操作，这样您只需编辑网站的网址和干净的域名即可。< / p>

Answer 4

这是在Android webView中加载网站的完整工作代码。只需从android studio创建一个新项目，然后使用以下代码加载网络视图即可。只需更改要在网络视图中加载的URL。

它将在webview中加载网站
它将检查互联网连接可用性
如果没有互联网，请要求用户从小吃店消息中启用WiFi
加载进度，直到网站加载
如果在加载网站时出现问题，则处理错误
处理后退按钮的情况下
句柄从吐司中退出应用确认

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rootView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <WebView
        android:id="@+id/webView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/infoTV"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.kt：

import android.annotation.SuppressLint
import android.content.Context
import android.content.Intent
import android.graphics.Bitmap
import android.net.ConnectivityManager
import android.net.NetworkCapabilities
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.provider.Settings
import android.util.Log
import android.view.KeyEvent
import android.webkit.WebResourceError
import android.webkit.WebResourceRequest
import android.webkit.WebView
import android.webkit.WebViewClient
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.google.android.material.snackbar.Snackbar
import kotlinx.android.synthetic.main.activity_main.*


class MainActivity : AppCompatActivity() {

    private var progress: Progress? = null
    private var isLoaded: Boolean = false
    private var doubleBackToExitPressedOnce = false
    private var webURL = "https://www.geeklabs.co.in/" // Change it with your URL

    @SuppressLint("SetJavaScriptEnabled")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        webView.settings.javaScriptEnabled = true
        if (!isOnline()) {
            showToast(getString(R.string.no_internet))
            infoTV.text = getString(R.string.no_internet)
            showNoNetSnackBar()
            return
        }
    }

    override fun onResume() {
        if (isOnline() && !isLoaded) loadWebView()
        super.onResume()
    }

    private fun loadWebView() {
        infoTV.text = ""
        webView.loadUrl(webURL)
        webView.webViewClient = object : WebViewClient() {
            override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
                val url = request?.url.toString()
                view?.loadUrl(url)
                return super.shouldOverrideUrlLoading(view, request)
            }

            override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
                setProgressDialogVisibility(true)
                super.onPageStarted(view, url, favicon)
            }

            override fun onPageFinished(view: WebView?, url: String?) {
                isLoaded = true
                setProgressDialogVisibility(false)
                super.onPageFinished(view, url)
            }

            override fun onReceivedError(view: WebView, request: WebResourceRequest, error: WebResourceError) {
                isLoaded = false
                val errorMessage = "Got Error! $error"
                showToast(errorMessage)
                infoTV.text = errorMessage
                setProgressDialogVisibility(false)
                super.onReceivedError(view, request, error)
            }
        }
    }

    override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
        if (event.action == KeyEvent.ACTION_DOWN) {
            if (keyCode == KeyEvent.KEYCODE_BACK) {
                if (webView.canGoBack()) {
                    webView.goBack()
                } else {
                    showToastToExit()
                }
                return true
            }
        }
        return super.onKeyDown(keyCode, event)
    }

    private fun showToastToExit() {
        when {
            doubleBackToExitPressedOnce -> {
                onBackPressed()
            }
            else -> {
                doubleBackToExitPressedOnce = true
                showToast(getString(R.string.back_again_to_exit))
                Handler(Looper.myLooper()!!).postDelayed({ doubleBackToExitPressedOnce = false }, 2000)
            }
        }
    }

    private fun setProgressDialogVisibility(visible: Boolean) {
        if (visible) progress = Progress(this, R.string.please_wait, cancelable = true)
        progress?.apply { if (visible) show() else dismiss() }
    }

    private fun isOnline(): Boolean {
        val connectivityManager =
                getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        val capabilities =
                connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)
        if (capabilities != null) {
            when {
                capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> {
                    Log.i("Internet", "NetworkCapabilities.TRANSPORT_CELLULAR")
                    return true
                }
                capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> {
                    Log.i("Internet", "NetworkCapabilities.TRANSPORT_WIFI")
                    return true
                }
                capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> {
                    Log.i("Internet", "NetworkCapabilities.TRANSPORT_ETHERNET")
                    return true
                }
            }
        }
        return false
    }

    private fun showToast(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
    }

    private fun showNoNetSnackBar() {
        val snack = Snackbar.make(rootView, getString(R.string.no_internet), Snackbar.LENGTH_INDEFINITE)
        snack.setAction(getString(R.string.settings)) {
            startActivity(Intent(Settings.ACTION_WIFI_SETTINGS))
        }
        snack.show()
    }
}

Progress.kt：

import android.app.AlertDialog
import android.app.Dialog
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.widget.TextView
import androidx.annotation.StringRes

class Progress constructor(
    context: Context?,
    @StringRes private val titleRes: Int,
    cancelable: Boolean = false
) {

    private var view: View? = null
    private var builder: AlertDialog.Builder
    private var dialog: Dialog

    init {
        view = LayoutInflater.from(context).inflate(R.layout.progress, null)
        view?.findViewById<TextView>(R.id.text)?.setText(titleRes)
        builder = AlertDialog.Builder(context)
        builder.setView(view)
        dialog = builder.create()
        dialog.setCancelable(cancelable)
    }

    fun setProgressMessage(@StringRes titleRes: Int) {
        view?.findViewById<TextView>(R.id.text)?.setText(titleRes)
    }

    fun show() {
        dialog.show()
    }

    fun dismiss() {
        if (dialog.isShowing) {
            dialog.dismiss()
        }
    }

    fun setProgressDialogVisibility(isVisible: Boolean) {

    }
}

pregress.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/linearLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center_vertical">

    <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp" />

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="@style/TextAppearance.AppCompat.SearchResult.Subtitle"
        tools:text="Loading" />

</LinearLayout>

Manifest.xml：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.geeklabs.webviewkotlin">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:fullBackupContent="false"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

strings.xml：

<resources>
    <string name="app_name">WebViewKotlin</string>
    <string name="please_wait">Please wait&#8230;</string>
    <string name="no_internet">No internet connection!</string>
    <string name="settings">Settings</string>
    <string name="back_again_to_exit">Please click BACK again to exit</string>
</resources>

build.gradle：

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.0"

    defaultConfig {
        applicationId "com.geeklabs.webviewkotlin"
        minSdkVersion 23
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.3.1'
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.android.material:material:1.1.0'
    testImplementation 'junit:junit:4.13'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

}

这是Git集线器中的完整工作代码。 Click here to navigate to Git Hub

如何使用Android Kotlin在WebView中加载URL？

4 个答案: