解決方法
1.在顯示的dialog的fragment或activity添加 android:windowSoftInputMode="adjustPan|stateAlwaysHidden"到Androidmanifest.xml
2.在自定義Dialog的onCreateView()方法里填加代碼

Window window = getDialog().getWindow();
window.clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);
window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);

3.修改dialog的style 新建style

<style name="dialog_soft_input" parent="Theme.AppCompat.Light.Dialog.Alert">
        <item name="android:windowSoftInputMode">stateVisible|adjustPan</item>
    </style>

@Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setStyle(DialogFragment.STYLE_NO_FRAME, R.style.dialog_soft_input);
    }

activity配置加上

 android:windowSoftInputMode="adjustPan|stateAlwaysHidden"