声明“flag_activity_no_animation”后出现NullPointerException警告

Question

在操作栏中为后退箭头定义flag_activity_no_animation以在单击工具栏后退箭头时更正为animation之后，将返回警告。摆脱这种警告的最好方法是什么？

方法调用“Add Flags”可能产生“java.lang.NullPointerException”

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == android.R.id.home) {
        final Intent intent = getParentActivityIntent();
        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        onBackPressed();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

Answer 1

将其包装成if intent！=null。

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == android.R.id.home) {
        final Intent intent = getParentActivityIntent();
        if(intent != null){
            intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        }else{
          //Do some error handling.
        }
        onBackPressed();
        return true;
    }
    return super.onOptionsItemSelected(item);
}