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Android中使用ViewStub提高布局性能

http://7jpolu.com1.z0.glb.clouddn.com/viestub_demo.png

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<?xml version="1.0" encoding="utf-8"?> <RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context="com.droidyue.viewstubsample.MainActivity"> <Button android:id="@+id/clickMe" android:text="Hello World!" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <ViewStub android:id="@+id/myViewStub" android:inflatedId="@+id/myInflatedViewId" android:layout="@layout/include_merge" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/clickMe" </RelativeLayout>

1 6	ViewStub myViewStub = (ViewStub)findViewById(R.id.myViewStub); if (myViewStub != null) { myViewStub.inflate(); //或者是下面的形式加载 //myViewStub.setVisibility(View.VISIBLE); }

1 13	<merge xmlns:android="http://schemas.android.com/apk/res/android"> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Yes"/> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="No"/> </merge>

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E AndroidRuntime: android.view.InflateException: Binary XML file line #1: <merge /> can be used only with a valid ViewGroup root and attachToRoot=true E AndroidRuntime: at android.view.LayoutInflater.inflate(LayoutInflater.java:551) E AndroidRuntime: at android.view.LayoutInflater.inflate(LayoutInflater.java:429) E AndroidRuntime: at android.view.ViewStub.inflate(ViewStub.java:259) E AndroidRuntime: at com.droidyue.viewstubsample.MainActivity$1.onClick(MainActivity.java:20) E AndroidRuntime: at android.view.View.performClick(View.java:5697) E AndroidRuntime: at android.widget.TextView.performClick(TextView.java:10815) E AndroidRuntime: at android.view.View$PerformClick.run(View.java:22526) E AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:739) E AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:95) E AndroidRuntime: at android.os.Looper.loop(Looper.java:158) E AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:7237) E AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) E AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) E AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) E AndroidRuntime: Caused by: android.view.InflateException: <merge /> can be used only with a valid ViewGroup root and attachToRoot=true E AndroidRuntime: at android.view.LayoutInflater.inflate(LayoutInflater.java:491) E AndroidRuntime: ... 13 more

1 7	<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <include layout="@layout/merge_layout"/> </LinearLayout>

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/** * When visibility is set to {@link #VISIBLE} or {@link #INVISIBLE}, * {@link #inflate()} is invoked and this StubbedView is replaced in its parent * by the inflated layout resource. * @param visibility One of {@link #VISIBLE}, {@link #INVISIBLE}, or {@link #GONE}. * @see #inflate() @Override public void setVisibility(int visibility) { if (mInflatedViewRef != null) { View view = mInflatedViewRef.get(); if (view != null) { view.setVisibility(visibility); } else { throw new IllegalStateException("setVisibility called on un-referenced view"); } else { super.setVisibility(visibility); if (visibility == VISIBLE || visibility == INVISIBLE) { inflate(); }

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/** * Inflates the layout resource identified by {@link #getLayoutResource()} * and replaces this StubbedView in its parent by the inflated layout resource. * @return The inflated layout resource. public View inflate() { final ViewParent viewParent = getParent(); if (viewParent != null && viewParent instanceof ViewGroup) { if (mLayoutResource != 0) { final ViewGroup parent = (ViewGroup) viewParent; final LayoutInflater factory = LayoutInflater.from(mContext); final View view = factory.inflate(mLayoutResource, parent, false); if (mInflatedId != NO_ID) { view.setId(mInflatedId); final int index = parent.indexOfChild(this); parent.removeViewInLayout(this); final ViewGroup.LayoutParams layoutParams = getLayoutParams(); if (layoutParams != null) { parent.addView(view, index, layoutParams); } else { parent.addView(view, index); mInflatedViewRef = new WeakReference<View>(view); if (mInflateListener != null) { mInflateListener.onInflate(this, view); return view; } else {

Android中使用ViewStub提高布局性能

Android中使用ViewStub提高布局性能

ViewStub是什么

ViewStub使用场景

ViewStub 怎么用

关于ViewStub的事

ViewStub的不足

验证一:直接标签

验证二 间接的ViewStub

关于ViewStub的一点代码剖析

inflate vs setVisibility

inflate源码