Java 无法从外部片段将文本放入textview?
我试图在片段内添加文本,但每当我调用函数:updateTextField时都会看到错误,虽然他是万事如意,但不知道经常尝试的问题是什么,有没有可能修改一些代码来纠正错误 请帮帮我 代码: //主要活动Java 无法从外部片段将文本放入textview?,java,android,Java,Android,我试图在片段内添加文本,但每当我调用函数:updateTextField时都会看到错误,虽然他是万事如意,但不知道经常尝试的问题是什么,有没有可能修改一些代码来纠正错误 请帮帮我 代码: //主要活动 public class MainActivity extends AppCompatActivity { private android.view.View mEditText; @Override protected void onCreate(Bundle sa
public class MainActivity extends AppCompatActivity {
private android.view.View mEditText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void test_btn(View V){
SecondFragment newGamefragment = new SecondFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment2 , newGamefragment);
transaction.addToBackStack(null);
transaction.commit();
newGamefragment.updateTextField("asdas");
}
}
//SecondFragment
public class SecondFragment extends Fragment {
private TextView updateText;
public SecondFragment(){
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_second, container, false);
updateText = (TextView)view.findViewById(R.id.text_update);
return view;
}
public void updateTextField(String newText){
updateText.setText(newText);
}
}
// xml mainactivity
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#574706"
tools:context=".MainActivity">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/fragment2"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
<TextView
android:id="@+id/tv_main"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HIHIH"
android:textSize="30dp"
android:textColor="#54ffff"
android:layout_below="@+id/fragment2"
android:layout_alignParentEnd="true"
android:layout_marginEnd="94dp"
android:layout_marginTop="39dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/tv_main"
android:onClick="test_btn"
/>
</RelativeLayout>
// xml fragment_second
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/text_update"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="h"
android:textColor="#ff0000"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:textStyle="bold"
android:layout_marginTop="32dp" />
</RelativeLayout>
您可以通过参数和onCreateView方法在第二个片段中传递
字符串
,您可以检索此参数并在文本视图中进行设置。下面是示例代码
在onClick
方法上添加以下代码
SecondFragment newGamefragment = SecondFragment.newInstance();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment2 , newGamefragment);
transaction.addToBackStack(null);
transaction.commit();
/**
* Create a new instance of secondFragment,
*/
public static SecondFragment newInstance(String yourString) {
secondFragment f = new secondFragment();
Bundle args = new Bundle();
args.putStirng("myString", yourString);
f.setArguments(args);
return f;
}
在片段的onCreateView
方法中检索字符串
Bundle args = getArguments();
String myString = args.getString("myString");
然后,将此字符串设置为textview
updateText.setText(myString);
您好,您无法访问MainActivity中的更改文本,您可以通过两种方式执行此操作: 1: 2:EventBus:
您将了解更多信息Logcat中的错误是什么?使用
setOnClickListener(…)
方法设置View.OnClickListener
。请参见:谢谢,但不能使用:new SecondFragment.newInstance(“asdas”),我使用SecondFragment.newInstance(“asdas”),没有新的
updateText.setText(myString);
public class MainActivity extends AppCompatActivity {
private android.view.View mEditText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void test_btn(View V){
SecondFragment newGamefragment = new SecondFragment.newInstance("asdas");
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment2 , newGamefragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
//SecondFragment
public class SecondFragment extends Fragment {
private TextView updateText;
public static SecondFragment newInstance(String str) {
SecondFragment s= new SecondFragment ();
Bundle args = new Bundle();
args.putString("str", str);
signUpFragment.setArguments(args);
return s;
}
public SecondFragment(){
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_second, container, false);
updateText = (TextView)view.findViewById(R.id.text_update);
if (getArguments() != null)
updateTextField( getArguments().getString("str"));
return view;
}
public void updateTextField(String newText){
updateText.setText(newText);
}
}