Question

//This is the TextViewExample class
public class TextViewExample {

private TextView mTextViewExample;

public TextViewExample(Activity activity) {
    mActivity = activity;
    mTextViewExample = (TextView)mActivity.findViewById(R.id.TextViewLayout);
    } 
}

//This is the Fragment class
public class TextViewFragment extends Fragment {

    private TextViewExample mText;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    mText = new TextViewExample(getActivity());
    }
}

用户界面中未更新

mText！有人可以通过调用片段中的活动来解释正确显示TextView的方法吗？

谢谢=）

Answer 1

您可以直接访问片段中的活动[<Fact>] let fact () = let rng = Random () let a = rng.Next() % 2 = 0 let b = rng.Next() % 2 = 0 a && b // <- breakpoint here works ()（假设此片段已附加到活动中）：

TextView

务必检查//This is the Fragment class public class TextViewFragment extends Fragment { private TextView mText; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // you need to inflate the xml file holding this TextView. mText = (TextView) getActivity().findViewByid(R.id.<your-text-view-id>; // do something with your TextView } }以避免NPE。

Answer 2

<强>活动：

 public class MainActivity {

    private TextView mTextViewExample;

    protected void onCreate(Bundle savedInstanceState) {
        ...
        mTextViewExample = (TextView) findViewById(R.id.TextViewLayout);
        } 
    }

    public void setTextViewExampleText(String text) {
        mTextViewExample.setText(text);
    }

<强> TextViewFragment

public class TextViewFragment extends Fragment {

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        ((MainActivity) getActivity()).setTextViewExampleText("text");
    }
}

android - TextView不会在UI中更新

2 个答案: