1

我和这个问题有同样的问题

在 Fragment 中更改 TextView

那里写的解决方案工作正常这是解决方案

  import android.os.Bundle;
    import android.support.v4.app.Fragment;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;

    public class DetailFragment extends Fragment {

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.details, container, false);
            return view;
        }


        public void setText(String text){
            TextView textView = (TextView) getView().findViewById(R.id.detailsText);
            textView.setText(text);
        }

    }

我的第一个问题-> 为什么 每当我尝试以这种方式在位于片段内的 TextView 中设置文本时，我的应用程序就会崩溃

在 Main-Activity 类的方法中

TextView  tv = (TextView)getView().findViewById(R.id.textView_question); 
   tv.setText(question);

第二个问题-> 在方法 setText 的解决方案中为什么我不能写这个

TextView textView = (TextView) getView().findViewById(R.id.detailsText);
            textView.setText(text);

至 

   TextView textView = (TextView)findViewById(R.id.detailsText);
            textView.setText(text);

当我尝试设置文本时记录 Cat（仅错误）

  07-08 18:40:33.462: E/AndroidRuntime(27881): FATAL EXCEPTION: main
07-08 18:40:33.462: E/AndroidRuntime(27881): java.lang.IllegalStateException: Could not execute method of the activity
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.view.View$1.onClick(View.java:3071)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.view.View.performClick(View.java:3538)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.view.View$PerformClick.run(View.java:14330)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.os.Handler.handleCallback(Handler.java:608)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.os.Handler.dispatchMessage(Handler.java:92)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.os.Looper.loop(Looper.java:156)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.app.ActivityThread.main(ActivityThread.java:4987)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at java.lang.reflect.Method.invokeNative(Native Method)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at java.lang.reflect.Method.invoke(Method.java:511)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at dalvik.system.NativeStart.main(Native Method)
07-08 18:40:33.462: E/AndroidRuntime(27881): Caused by: java.lang.reflect.InvocationTargetException
07-08 18:40:33.462: E/AndroidRuntime(27881):    at java.lang.reflect.Method.invokeNative(Native Method)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at java.lang.reflect.Method.invoke(Method.java:511)
07-08 18:40:33.462: E/AndroidRuntime(27881):    at android.view.View$1.onClick(View.java:3066)
07-08 18:40:33.462: E/AndroidRuntime(27881):    ... 11 more
07-08 18:40:33.462: E/AndroidRuntime(27881): Caused by: java.lang.NullPointerException
07-08 18:40:33.462: E/AndroidRuntime(27881):    at com.alisaeed.newramadan.MainActivity.question_displayer(MainActivity.java:64)
07-08 18:40:33.462: E/AndroidRuntime(27881):    ... 14 more

新代码

public void  question_displayer(View v){


    Log.i("create","question_displayer()");
    RamadanData data_object = new RamadanData();


    FragmentTransaction fragment_question = getSupportFragmentManager().beginTransaction();
    fragment_question.replace(R.id.framelayout1, new fragment_question_displayer()  , null);
    fragment_question.addToBackStack(null);
    fragment_question.commit();

     TextView tv = (TextView)findViewById(R.id.textView_question);



    switch(v.getId()){
    case (R.id.buttonPrayer):
    {


        Log.i("create","prayer()");

        if(child_selected == true && adult_selected==false && teen_selected==false )
        {
            Log.i("create","child_selected");

           String question= data_object.question_output(flag_autoquestion, "child","prayer");      
           Log.i("create",question);

           tv.setText(question);

           flag_autoquestion++;
                                         }       




    }



}


}
4

2 回答 2

1

在片段中，您将调用这样的文本视图

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.details, container, false);
        TextView textView = (TextView) view.findViewById(R.id.detailsText);
        String text = "sample text";
        textView.setText(text);
        return view;
    }

设置您的文本。另一方面，在活动课上会是这样的

setContentView(R.activity_layout);
TextView  tv = (TextView) findViewById(R.id.textView_question); 
tv.setText(question);
于 2013-07-08T13:53:33.517 回答
1

添加类描述：

TextView textView;

在 onCreateView(...) 中定义 TextView

View view = inflater.inflate(R.layout.details, container, false);

TextView textView = (TextView) view.findViewById(R.id.detailsText);

在您可以从此类的任何地方使用 textView 之后。

于 2013-07-08T13:54:34.647 回答