您好我正在使用Android Studio，目前正在为网站制作WebView应用
如何在加载时检查互联网而不是显示默认错误 - 网页不可用而不是我可以显示一些图形图像吗？
我的代码
Activity_fullscreen.xml
<FrameLayout 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"
android:background="#0099cc"
tools:context="com.croogster.android.FullscreenActivity">
<!-- The primary full-screen view. This can be replaced with whatever view
is needed to present your content, e.g. VideoView, SurfaceView,
TextureView, etc. -->
<TextView
android:id="@+id/fullscreen_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:keepScreenOn="true"
android:text="@string/dummy_content"
android:textColor="#33b5e5"
android:textSize="50sp"
android:textStyle="bold" />
<!-- This FrameLayout insets its children based on system windows using
android:fitsSystemWindows. -->
<LinearLayout
android:id="@+id/fullscreen_content_controls"
style="?metaButtonBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:background="@color/black_overlay"
android:orientation="horizontal"
tools:ignore="UselessParent">
</LinearLayout>
<WebView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/webView"
android:layout_gravity="left|bottom" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
</FrameLayout>
FullscreenActivity.java
public class FullscreenActivity extends AppCompatActivity {
/**
* Whether or not the system UI should be auto-hidden after
* {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
*/
private static final boolean AUTO_HIDE = true;
/**
* If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
* user interaction before hiding the system UI.
*/
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
/**
* Some older devices needs a small delay between UI widget updates
* and a change of the status and navigation bar.
*/
private static final int UI_ANIMATION_DELAY = 300;
private final Handler mHideHandler = new Handler();
private View mContentView;
private final Runnable mHidePart2Runnable = new Runnable() {
@SuppressLint("InlinedApi")
@Override
public void run() {
// Delayed removal of status and navigation bar
// Note that some of these constants are new as of API 16 (Jelly Bean)
// and API 19 (KitKat). It is safe to use them, as they are inlined
// at compile-time and do nothing on earlier devices.
mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
}
};
private View mControlsView;
private final Runnable mShowPart2Runnable = new Runnable() {
@Override
public void run() {
// Delayed display of UI elements
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.show();
}
mControlsView.setVisibility(View.VISIBLE);
}
};
private boolean mVisible;
private final Runnable mHideRunnable = new Runnable() {
@Override
public void run() {
hide();
}
};
/**
* Touch listener to use for in-layout UI controls to delay hiding the
* system UI. This is to prevent the jarring behavior of controls going away
* while interacting with activity UI.
*/
private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (AUTO_HIDE) {
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
return false;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fullscreen);
WebView view = (WebView) this.findViewById(R.id.webView);
view.setWebViewClient(new WebViewClient());
view.loadUrl("https://croogster.com");
view.getSettings().setJavaScriptEnabled(true);
mVisible = true;
mControlsView = findViewById(R.id.fullscreen_content_controls);
mContentView = findViewById(R.id.fullscreen_content);
// Set up the user interaction to manually show or hide the system UI.
mContentView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
toggle();
}
});
// Upon interacting with UI controls, delay any scheduled hide()
// operations to prevent the jarring behavior of controls going away
// while interacting with the UI.
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Trigger the initial hide() shortly after the activity has been
// created, to briefly hint to the user that UI controls
// are available.
delayedHide(100);
}
private void toggle() {
if (mVisible) {
hide();
} else {
show();
}
}
private void hide() {
// Hide UI first
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.hide();
}
mControlsView.setVisibility(View.GONE);
mVisible = false;
// Schedule a runnable to remove the status and navigation bar after a delay
mHideHandler.removeCallbacks(mShowPart2Runnable);
mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
}
@SuppressLint("InlinedApi")
private void show() {
// Show the system bar
mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
mVisible = true;
// Schedule a runnable to display UI elements after a delay
mHideHandler.removeCallbacks(mHidePart2Runnable);
mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
}
/**
* Schedules a call to hide() in [delay] milliseconds, canceling any
* previously scheduled calls.
*/
private void delayedHide(int delayMillis) {
mHideHandler.removeCallbacks(mHideRunnable);
mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
}
和我的AndroidMainfest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.croogster.android">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".Splashscreen"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".FullscreenActivity"
android:configChanges="orientation|keyboardHidden|screenSize"
android:label="@string/app_name"
android:theme="@style/FullscreenTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
帮帮我
答案 0 :(得分：2)
您应该在WebView上设置WebViewClient：
MyWebViewClient mWebViewClient;
WebView mWebView;
mWebView.setWebViewClient(mWebViewClient);
WebViewClient应该扩展WebViewClient：
class MyWebViewClient extends WebViewClient{}
在这个课程中你可以覆盖onReceivedError，它会报告发生的错误（其中一个是你没有连接的时候（我认为它是errorCode -2）：
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
super.onReceivedError(view, errorCode, description, failingUrl);
Log.d("error code", " " + String.valueOf(errorCode));
if (errorCode == -2) //errorCode 2 -> Server or proxy hostname lookup failed (no connection)
// show to the user whatever you want to show, for example, a local html page:
view.loadUrl("file:///android_asset/localhtmlpagenoconnection.html");
}
希望它对你有所帮助。
答案 1 :(得分：0)
您可以使用WebView Client。
Computed答案 2 :(得分：0)
呼叫连接管理器的isActiveNetworkMetered()就是这样。将以下代码复制并粘贴到您的活动中。
ConnectivityManager cm =
(ConnectivityManager)getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
boolean isMetered = cm.isActiveNetworkMetered();
if (isMetered==true){
//Device has an active internet connection.
//Do your stub here
}
else {
//Device has no active internet connection.
//Do your stub here
}