android invalidate和postinvalidate源码分析

Posted 2021-02-06 坚持v

postinvalidate源码分析

view中

public void postInvalidate() {
        postInvalidateDelayed(0);
    }

    public void postInvalidateDelayed(long delayMilliseconds) {
        // We try only with the AttachInfo because there\'s no point in invalidating
        // if we are not attached to our window
        final AttachInfo attachInfo = mAttachInfo;
        if (attachInfo != null) {
            attachInfo.mViewRootImpl.dispatchInvalidateDelayed(this, delayMilliseconds);
        }
    }

    public void dispatchInvalidateDelayed(View view, long delayMilliseconds) {
        Message msg = mHandler.obtainMessage(MSG_INVALIDATE, view);
        mHandler.sendMessageDelayed(msg, delayMilliseconds);
    }

  switch (msg.what) {
            case MSG_INVALIDATE:
                ((View) msg.obj).invalidate();
                break;

其他的和invalidate一样，着我们就可以看到了，postinvalidate在主线程和非主线程中都可以调用，但是Invalidate不能直接在线程中调用

作者：Peakmain
链接：https://www.jianshu.com/p/6c5d65009ba1