使用kotlin扩展函数会更好

inline fun View.waitForLayout(crossinline yourAction: () -> Unit) {
    val vto = viewTreeObserver
    vto.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
        override fun onGlobalLayout() {
            when {
                vto.isAlive -> {
                    vto.removeOnGlobalLayoutListener(this)
                    yourAction()
                }
                else -> viewTreeObserver.removeOnGlobalLayoutListener(this)
            }
        }
    })
}

视图。post {TODO(“尚未实现”)}

最优雅的方法是使用OneShotPreDrawListener。OneShotPreDrawListener将注册一个回调函数，在视图树即将被绘制时调用，并且它将在一次OnPreDraw调用后删除自己。

OneShotPreDrawListener.add(view) {
    view.doSomething();
}

androidx。Core-ktx已经有了

/**
 * Performs the given action when this view is next laid out.
 *
 * The action will only be invoked once on the next layout and then removed.
 *
 * @see doOnLayout
 */
public inline fun View.doOnNextLayout(crossinline action: (view: View) -> Unit) {
    addOnLayoutChangeListener(object : View.OnLayoutChangeListener {
        override fun onLayoutChange(
            view: View,
            left: Int,
            top: Int,
            right: Int,
            bottom: Int,
            oldLeft: Int,
            oldTop: Int,
            oldRight: Int,
            oldBottom: Int
        ) {
            view.removeOnLayoutChangeListener(this)
            action(view)
        }
    })
}

/**
 * Performs the given action when this view is laid out. If the view has been laid out and it
 * has not requested a layout, the action will be performed straight away, otherwise the
 * action will be performed after the view is next laid out.
 *
 * The action will only be invoked once on the next layout and then removed.
 *
 * @see doOnNextLayout
 */
public inline fun View.doOnLayout(crossinline action: (view: View) -> Unit) {
    if (ViewCompat.isLaidOut(this) && !isLayoutRequested) {
        action(this)
    } else {
        doOnNextLayout {
            action(it)
        }
    }
}

我创建静态变量来检查布局是否已经绘制。如果它已经创建，你可以简单地调用绘制的函数。

static int firstAccess = 0;
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main8);

    if (firstAccess==0) {
        LAYOUT_YOU_DRAW.post(new Runnable() {
            @Override
            public void run() {
                creatSpread();
                firstAccess = 1;
            }
        });
    }else{
        creatSpread();
    }
}

要避免弃用代码和警告，您可以使用:

view.getViewTreeObserver().addOnGlobalLayoutListener(
        new ViewTreeObserver.OnGlobalLayoutListener() {
            @SuppressWarnings("deprecation")
            @Override
            public void onGlobalLayout() {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                    view.getViewTreeObserver()
                            .removeOnGlobalLayoutListener(this);
                } else {
                    view.getViewTreeObserver()
                            .removeGlobalOnLayoutListener(this);
                }
                yourFunctionHere();
            }
        });