【Android】onActivityResult()和onResume()的调用顺序问题

墨蓝 2022-08-08 15:37 214阅读 0赞

> 在Android生命周期中，如果使用到startActivityForResult()，则在新Activity被finish掉之后，onActivityResult()和onResume()到底是哪一个先调用的呢？

我们来看官方源码：

/**
         * Called when an activity you launched exits, giving you the requestCode
         * you started it with, the resultCode it returned, and any additional
         * data from it.  The <var>resultCode</var> will be
         * {@link #RESULT_CANCELED} if the activity explicitly returned that,
         * didn't return any result, or crashed during its operation.
         *
         * <p>You will receive this call immediately before onResume() when your
         * activity is re-starting.
         *
         * <p>This method is never invoked if your activity sets
         * {@link android.R.styleable#AndroidManifestActivity_noHistory noHistory} to
         * <code>true</code>.
         *
         * @param requestCode The integer request code originally supplied to
         *                    startActivityForResult(), allowing you to identify who this
         *                    result came from.
         * @param resultCode The integer result code returned by the child activity
         *                   through its setResult().
         * @param data An Intent, which can return result data to the caller
         *               (various data can be attached to Intent "extras").
         *
         * @see #startActivityForResult
         * @see #createPendingResult
         * @see #setResult(int)
         */
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        }

从上面的源码注释第二段可以看到：You will receive this call immediately before onResume() when your activity is re-starting. 所以很明显，在activity重新恢复启动的时候，**onActivityResult()会在onResume()之前调用完毕。**

而且，onActivityResult()还会在onStart()之前调用完毕。经过断点调试，发现它们三者的调用顺序如下：

*  **onActivityResult() -> onStart() -> onResume()**