Activity的setContentView（）

 

1.调用的是PhoneWindow的setContentView

PhoneWindow.java
 
@Override
    public void setContentView(int layoutResID) {
        // Note: FEATURE_CONTENT_TRANSITIONS may be set in the process of installing the window
        // decor, when theme attributes and the like are crystalized. Do not check the feature
        // before this happens.
        if (mContentParent == null) {
            installDecor();
        } else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            mContentParent.removeAllViews();
        }

        if (hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            final Scene newScene = Scene.getSceneForLayout(mContentParent, layoutResID,
                    getContext());
            transitionTo(newScene);
        } else {
            mLayoutInflater.inflate(layoutResID, mContentParent);
        }
        mContentParent.requestApplyInsets();
        final Callback cb = getCallback();
        if (cb != null && !isDestroyed()) {
            cb.onContentChanged();
        }
        mContentParentExplicitlySet = true;
    }

 2.初始化DecorView,调用installDecoer()方法

if (mContentParent == null) {
    installDecor();
} else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
    mContentParent.removeAllViews();
}

3.点进去installDecor()方法

...
重点是这一行代码
mContentParent = generateLayout(mDecor);//生成内容视图区域，此时加载的是系统布局资源，比如有ActionBar的和不带ActionBar的，以及其他样式的系统布局
...

4.继续点进去看上述方法

//首先会为window设置一系列的主题样式

 mIsFloating = a.getBoolean(R.styleable.Window_windowIsFloating, false);
        int flagsToUpdate = (FLAG_LAYOUT_IN_SCREEN|FLAG_LAYOUT_INSET_DECOR)
                & (~getForcedWindowFlags());
        if (mIsFloating) {
            setLayout(WRAP_CONTENT, WRAP_CONTENT);
            setFlags(0, flagsToUpdate);
        } else {
            setFlags(FLAG_LAYOUT_IN_SCREEN|FLAG_LAYOUT_INSET_DECOR, flagsToUpdate);
        }

        if (a.getBoolean(R.styleable.Window_windowNoTitle, false)) {
            requestFeature(FEATURE_NO_TITLE);
        } else if (a.getBoolean(R.styleable.Window_windowActionBar, false)) {
            // Don't allow an action bar if there is no title.
            requestFeature(FEATURE_ACTION_BAR);
        }

        if (a.getBoolean(R.styleable.Window_windowActionBarOverlay, false)) {
            requestFeature(FEATURE_ACTION_BAR_OVERLAY);
        }

        if (a.getBoolean(R.styleable.Window_windowActionModeOverlay, false)) {
            requestFeature(FEATURE_ACTION_MODE_OVERLAY);
        }

        if (a.getBoolean(R.styleable.Window_windowSwipeToDismiss, false)) {
            requestFeature(FEATURE_SWIPE_TO_DISMISS);
        }

        if (a.getBoolean(R.styleable.Window_windowFullscreen, false)) {
            setFlags(FLAG_FULLSCREEN, FLAG_FULLSCREEN & (~getForcedWindowFlags()));
        }

        if (a.getBoolean(R.styleable.Window_windowTranslucentStatus,
                false)) {
            setFlags(FLAG_TRANSLUCENT_STATUS, FLAG_TRANSLUCENT_STATUS
                    & (~getForcedWindowFlags()));
        }

        if (a.getBoolean(R.styleable.Window_windowTranslucentNavigation,
                false)) {
            setFlags(FLAG_TRANSLUCENT_NAVIGATION, FLAG_TRANSLUCENT_NAVIGATION
                    & (~getForcedWindowFlags()));
        }

        if (a.getBoolean(R.styleable.Window_windowOverscan, false)) {
            setFlags(FLAG_LAYOUT_IN_OVERSCAN, FLAG_LAYOUT_IN_OVERSCAN&(~getForcedWindowFlags()));
        }

        if (a.getBoolean(R.styleable.Window_windowShowWallpaper, false)) {
            setFlags(FLAG_SHOW_WALLPAPER, FLAG_SHOW_WALLPAPER&(~getForcedWindowFlags()));
        }

        if (a.getBoolean(R.styleable.Window_windowEnableSplitTouch,
                getContext().getApplicationInfo().targetSdkVersion
                        >= android.os.Build.VERSION_CODES.HONEYCOMB)) {
            setFlags(FLAG_SPLIT_TOUCH, FLAG_SPLIT_TOUCH&(~getForcedWindowFlags()));
        }

        a.getValue(R.styleable.Window_windowMinWidthMajor, mMinWidthMajor);
        a.getValue(R.styleable.Window_windowMinWidthMinor, mMinWidthMinor);
        if (DEBUG) Log.d(TAG, "Min width minor: " + mMinWidthMinor.coerceToString()
                + ", major: " + mMinWidthMajor.coerceToString());
        if (a.hasValue(R.styleable.Window_windowFixedWidthMajor)) {
            if (mFixedWidthMajor == null) mFixedWidthMajor = new TypedValue();
            a.getValue(R.styleable.Window_windowFixedWidthMajor,
                    mFixedWidthMajor);
        }
        if (a.hasValue(R.styleable.Window_windowFixedWidthMinor)) {
            if (mFixedWidthMinor == null) mFixedWidthMinor = new TypedValue();
            a.getValue(R.styleable.Window_windowFixedWidthMinor,
                    mFixedWidthMinor);
        }
        if (a.hasValue(R.styleable.Window_windowFixedHeightMajor)) {
            if (mFixedHeightMajor == null) mFixedHeightMajor = new TypedValue();
            a.getValue(R.styleable.Window_windowFixedHeightMajor,
                    mFixedHeightMajor);
        }
        if (a.hasValue(R.styleable.Window_windowFixedHeightMinor)) {
            if (mFixedHeightMinor == null) mFixedHeightMinor = new TypedValue();
            a.getValue(R.styleable.Window_windowFixedHeightMinor,
                    mFixedHeightMinor);
        }
        if (a.getBoolean(R.styleable.Window_windowContentTransitions, false)) {
            requestFeature(FEATURE_CONTENT_TRANSITIONS);
        }
        if (a.getBoolean(R.styleable.Window_windowActivityTransitions, false)) {
            requestFeature(FEATURE_ACTIVITY_TRANSITIONS);
        }

5.加载系统布局资源Id

// Inflate the window decor.

int layoutResource;

//拿到Id,绘制view并且添加到DecorView上
 mDecor.onResourcesLoaded(mLayoutInflater, layoutResource);

点进去onResourcesLoaded()

//加载布局并且添加到第一个位置

 final View root = inflater.inflate(layoutResource, null);
        if (mDecorCaptionView != null) {
            if (mDecorCaptionView.getParent() == null) {
                addView(mDecorCaptionView,
                        new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
            }
            mDecorCaptionView.addView(root,
                    new ViewGroup.MarginLayoutParams(MATCH_PARENT, MATCH_PARENT));
        } else {

            // Put it below the color views.
            addView(root, 0, new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
        }
        mContentRoot = (ViewGroup) root;

6.返回内容视图，id为R.id.content

ViewGroup contentParent = (ViewGroup)findViewById(ID_ANDROID_CONTENT);
...
return contentParent;

7.回到setContentView()

//加载自己的布局id到mContentParent上，也就是R.id.content下面
mLayoutInflater.inflate(layoutResID, mContentParent);

 

标签：getBoolean,false,setContentView,Window,styleable,FEATURE,FLAG,Activity
来源： https://blog.csdn.net/qq_37029648/article/details/109547664