今天遇到這樣的一個bug，我的測試機是Android 7.0，經過追蹤得到一下關鍵出錯資訊：

An activity without a UI must call finish() before onResume() completes

很明顯這是因為當前的activity沒有UI造成的，通過檢視原始碼發現這個問題在6.0之前不存在，在6.0之後google對著快做了強制要求，下面是

Android 6.0相應的原始碼：

final void performResume() {
    performRestart();
    mFragments.execPendingActions();
    mLastNonConfigurationInstances = null
 
;
    mCalled = false;
    // mResumed is set by the instrumentation
    mInstrumentation.callActivityOnResume(this);
    if (!mCalled) {
       throw new SuperNotCalledException(
           "Activity " + mComponent.toShortString() +
           " did not call through to super.onResume()");
    }

    // invisible activities must be finished before onResume() completes
 

    if (!mVisibleFromClient && !mFinished) {
        Log.w(TAG, "An activity without a UI must call finish() before onResume() completes");
        if (getApplicationInfo().targetSdkVersion
                > android.os.Build.VERSION_CODES.LOLLIPOP_MR1) {
            throw new IllegalStateException(
                   "Activity "
 
 + mComponent.toShortString() +
                   " did not call finish() prior to onResume() completing");
       }
   }
   // Now really resume, and install the current status bar and menu.
   mCalled = false;
   mFragments.dispatchResume();
   mFragments.execPendingActions();
   onPostResume();
   if (!mCalled) {
       throw new SuperNotCalledException(
           "Activity " + mComponent.toShortString() +
           " did not call through to super.onPostResume()");
    }
}

16行就是打出的出錯日誌

知道為什麼出錯後解決這個問題就不難了，既然我的activity是沒有UI的，出錯的activity主題的配置如下：

<activity android:name=".DialogActivity" 
    ...
    android:theme="@android:style/Theme.NoDisplay/>

這個一個沒有UI的主題，為了解決問題，只需要將主題改成透明的即可，ps：記住透明不等於沒有UI哦，如下所示：

<activity android:name=".DialogActivity" 
    ...
    android:theme="@android:style/Theme.Translucent.NoTitleBar"/>