我有以下代码：
public View onCreateView(LayoutInflater _inflater, ViewGroup _group, Bundle _savedInstanceState) {
Log.w(getClass().getName(), "start");
View view = _inflater.inflate(R.layout.myLayout, _group, false);
Log.w(getClass().getName(), "stop");
return view;
}
情况1：
//myLayout.xml
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView 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:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
11:50:36.370 onCreateView: start
11:50:36.410
onCreateView: stop
Execution time: 40ms
然后我添加一个WebView,不要触及任何其他代码
案例2：
//myLayout.xml
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView 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:layout_width="match_parent"
android:layout_height="match_parent"/>
<WebView
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
11:51:16.645 onCreateView: start
11:51:16.985
onCreateView: stop
Execution time: 340ms
正如你所看到的,存在巨大的差异,我看到我的界面在第二种情况下滞后.
1)这是预期的行为吗？
2)如果是这样,我如何摆脱UI中的滞后？
提前致谢
编辑：
第二种情况的完整日志：
11:51:16.645 onCreateView: start
11:51:16.710 I/WebViewFactory: Loading com.google.android.webview version 51.0.2704.81 (code 270408100)
11:51:16.740 W/art: Suspending all threads took: 11.333ms
11:51:16.755 I/cr_LibraryLoader: Time to load native libraries: 2 ms (timestamps 5137-5139)
11:51:16.755 I/cr_LibraryLoader: Expected native library version number "51.0.2704.81", actual native library version number "51.0.2704.81"
11:51:16.765 V/WebViewChromiumFactoryProvider: Binding Chromium to main looper Looper (main, tid 1) {1d66229a}
11:51:16.765 I/cr_LibraryLoader: Expected native library version number "51.0.2704.81", actual native library version number "51.0.2704.81"
11:51:16.765 I/chromium: [INFO:library_loader_hooks.cc(143)] Chromium logging enabled: level = 0, default verbosity = 0
11:51:16.795 I/cr_BrowserStartup: Initializing chromium process, singleProcess=true
11:51:16.805 E/ApkAssets: Error while loading asset assets/natives_blob_64.bin: java.io.FileNotFoundException: assets/natives_blob_64.bin
11:51:16.805 E/ApkAssets: Error while loading asset assets/snapshot_blob_64.bin: java.io.FileNotFoundException: assets/snapshot_blob_64.bin
11:51:16.870 W/cr_media: Requires BLUETOOTH permission
11:51:16.885 I/art: Rejecting re-init on previously-failed class java.lang.Class<com.android.webview.chromium.WebViewContentsClientAdapter$WebResourceErrorImpl>
11:51:16.885 I/art: Rejecting re-init on previously-failed class java.lang.Class<com.android.webview.chromium.WebViewContentsClientAdapter$WebResourceErrorImpl>
11:51:16.920 D/ConnectivityManager.CallbackHandler: CM callback handler got msg 524290
11:51:16.935 11557-11588/? W/FlurryAgent: Flurry session ended
11:51:16.945 I/art: Rejecting re-init on previously-failed class java.lang.Class<org.chromium.content.browser.FloatingWebActionModeCallback>
11:51:16.945 I/art: Rejecting re-init on previously-failed class java.lang.Class<org.chromium.content.browser.FloatingWebActionModeCallback>
11:51:16.970 D/cr_Ime: [InputMethodManagerWrapper.java:30] Constructor
11:51:16.980 W/cr_AwContents: onDetachedFromWindow called when already detached. Ignoring
11:51:16.980 D/cr_Ime: [InputMethodManagerWrapper.java:59] isActive: false
11:51:16.985 onCreateView: stop
最佳答案 不要使用XML创建它(设计)在后台线程中实际创建它,并在加载页面时将其添加到布局中.
这是很好的Example在相对布局中以编程方式创建它.
更新：
当我们在布局中添加任何小部件时,它意味着在我们使用java代码之前我们没有做任何事情.
<WebView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/webView"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
当您使用setContentView()时,在您的XML布局中编写上述代码时,WebView将使用其给定的属性执行.
WebView是类,它将使用给定的属性集执行其构造函数
/**
* Constructs a new WebView with a Context object.
*
* @param context a Context object used to access application assets
*/
public WebView(Context context) {
this(context, null);
}
/**
* Constructs a new WebView with layout parameters.
*
* @param context a Context object used to access application assets
* @param attrs an AttributeSet passed to our parent
*/
public WebView(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.webViewStyle);
}
/**
* Constructs a new WebView with layout parameters and a default style.
*
* @param context a Context object used to access application assets
* @param attrs an AttributeSet passed to our parent
* @param defStyleAttr an attribute in the current theme that contains a
* reference to a style resource that supplies default values for
* the view. Can be 0 to not look for defaults.
*/
public WebView(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
/**
* Constructs a new WebView with layout parameters and a default style.
*
* @param context a Context object used to access application assets
* @param attrs an AttributeSet passed to our parent
* @param defStyleAttr an attribute in the current theme that contains a
* reference to a style resource that supplies default values for
* the view. Can be 0 to not look for defaults.
* @param defStyleRes a resource identifier of a style resource that
* supplies default values for the view, used only if
* defStyleAttr is 0 or can not be found in the theme. Can be 0
* to not look for defaults.
*/
public WebView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
this(context, attrs, defStyleAttr, defStyleRes, null, false);
}
/**
* Constructs a new WebView with layout parameters and a default style.
*
* @param context a Context object used to access application assets
* @param attrs an AttributeSet passed to our parent
* @param defStyleAttr an attribute in the current theme that contains a
* reference to a style resource that supplies default values for
* the view. Can be 0 to not look for defaults.
* @param privateBrowsing whether this WebView will be initialized in
* private mode
*
* @deprecated Private browsing is no longer supported directly via
* WebView and will be removed in a future release. Prefer using
* {@link WebSettings}, {@link WebViewDatabase}, {@link CookieManager}
* and {@link WebStorage} for fine-grained control of privacy data.
*/
@Deprecated
public WebView(Context context, AttributeSet attrs, int defStyleAttr,
boolean privateBrowsing) {
this(context, attrs, defStyleAttr, 0, null, privateBrowsing);
}
/**
* Constructs a new WebView with layout parameters, a default style and a set
* of custom Javscript interfaces to be added to this WebView at initialization
* time. This guarantees that these interfaces will be available when the JS
* context is initialized.
*
* @param context a Context object used to access application assets
* @param attrs an AttributeSet passed to our parent
* @param defStyleAttr an attribute in the current theme that contains a
* reference to a style resource that supplies default values for
* the view. Can be 0 to not look for defaults.
* @param javaScriptInterfaces a Map of interface names, as keys, and
* object implementing those interfaces, as
* values
* @param privateBrowsing whether this WebView will be initialized in
* private mode
* @hide This is used internally by dumprendertree, as it requires the javaScript interfaces to
* be added synchronously, before a subsequent loadUrl call takes effect.
*/
protected WebView(Context context, AttributeSet attrs, int defStyleAttr,
Map<String, Object> javaScriptInterfaces, boolean privateBrowsing) {
this(context, attrs, defStyleAttr, 0, javaScriptInterfaces, privateBrowsing);
}
/**
* @hide
*/
@SuppressWarnings("deprecation") // for super() call into deprecated base class constructor.
protected WebView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes,
Map<String, Object> javaScriptInterfaces, boolean privateBrowsing) {
super(context, attrs, defStyleAttr, defStyleRes);
if (context == null) {
throw new IllegalArgumentException("Invalid context argument");
}
sEnforceThreadChecking = context.getApplicationInfo().targetSdkVersion >=
Build.VERSION_CODES.JELLY_BEAN_MR2;
checkThread();
ensureProviderCreated();
mProvider.init(javaScriptInterfaces, privateBrowsing);
// Post condition of creating a webview is the CookieSyncManager.getInstance() is allowed.
CookieSyncManager.setGetInstanceIsAllowed();
}
以上代码仍然只通过在xml布局中添加WebView来执行.
这就是为什么花时间.
希望您能理解并在WebView类中添加断点并检查您的理解.
