android开发记录

1. CheckBox的问题

checkbox用theme设置style

<CheckBox 
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" 
   android:checked="true"
   android:text="Check Box" 
   android:theme="@style/MyCheckBox"/>

2.Fragment跳转和回退

//跳转
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.replace(((BaseActivity) getActivity()).getFragmentContainerViewId(), fragment);
fragmentTransaction.addToBackStack(null);fragmentTransaction.commit();

//回退
 @Override
    public void onResume() {

        super.onResume();

        getView().setFocusableInTouchMode(true);
        getView().requestFocus();
        getView().setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {

                if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                    getActivity().getSupportFragmentManager().popBackStack();
                    return true;
                }
                return false;
            }
        });
    }

3.Fragment切换重叠问题

https://github.com/nicegoing/FragmentDemo

4. 键盘挡住输入框问题

Activity设置该属性，stateAlwaysHidden表示键盘在Activity获取焦点时隐藏.adjustResize表示软键盘弹出时，Activity的窗口大小改变。这样Activity的ScrollView不能显示完全，可以滑动。
android:windowSoftInputMode="stateAlwaysHidden|adjustResize"

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true">

        <!-- Other Views -->
</ScrollView>

5. inflate的context问题

使用application使用的是application的主题，使用activity使用的是activity的主题。

6. EditText抢占焦点问题

In case the view is the first EditText it seems clearFocus() clears its focus but then starts searching for a focus candidate through the view tree and then finds out the same view. And the result is the same. But if you put android:focusableInTouchMode the focus traversal ends up on its parent.

7.DialogFragment解决重复添加问题

    private void showAllowingStateLoss(@NonNull FragmentManager manager, String tag) {
        final FragmentTransaction transaction = manager.beginTransaction();
        transaction.remove(this);
        transaction.add(this, tag);
        transaction.commitAllowingStateLoss();
    }

8.toolbar设置title

如果使用toolbar.setTilte，需要在setSupportActionBar之前调用才会生效。直接使用Activity的setTitle方法就可设置title。