Question

我希望在Api大于17时使用方法重置setContentView中的视图：setLayoutDirection但是出现了这个错误

 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setLayoutDirection(int)' on a null object reference

以下代码有什么问题。 Tnx提前。

     @Override
     protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_settings);

    if(Build.VERSION.SDK_INT>=17)
    {
        Locale en = new Locale("e@Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_settings);

    if(Build.VERSION.SDK_INT>=17)
    {
        Locale en = new Locale("fa");
        Locale.setDefault(en);
        Configuration config = new Configuration();
        config.locale = en;
          getApplicationContext().getResources().updateConfiguratio n(config,getApplicationContext().getResources().getDisplayMetrics());
           ViewCompat.setLayoutDirection(findViewById(R.id.setting_listview_brightness),ViewCompat.LAYOUT_DIRECTION_RTL);
           setContentView(R.layout.activity_settings);

Answer 1

请使用：

 @Override
 protected void onCreate(Bundle savedInstanceState) {

    if (android.os.Build.VERSION.SDK_INT >17)
        setContentView(R.layout.your_layout);
    }else {
        setContentView(R.layout.your_layout_before_17);
    }

    //Do your other stuff.

}

希望这有帮助

Answer 2

就这样做

if(Build.VERSION.SDK_INT>=17)
{
    Locale en = new Locale("fa");
    Locale.setDefault(en);
    Configuration config = new Configuration();
    config.locale = en;
    getApplicationContext().getResources().updateConfiguratio n(config,getApplicationContext().getResources().getDisplayMetrics());
    ViewCompat.setLayoutDirection(findViewById(R.id.setting_listview_brightness),ViewCompat.LAYOUT_DIRECTION_RTL);
    setContentView(R.layout.your_layout_for17);
}

Android刷新视图不起作用

2 个答案: