我知道有很多关于这个的线索,但我似乎无法真正理解如何解决它。我基本上尝试做的是在 fragment B 中单击按钮后我想返回到 fragment A 和id 值..
因此,在我的 BackStack 中,您转到 Fragment A,然后转到 Fragment B,当按下按钮时,我想返回到 Fragment A 并显示一个值。这是我在 fragment B 中的 onClick 监听器:
//Fragment B which i called from Fragment A
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(value.getText().toString().trim().length() != 0) {
String order = value.getText().toString(); //The value i want in Fragment B
//return to Fragment A
}
}
在我的 MainActivity 中,我像这样处理我的 fragment :
//fragmentManager is initialized in onCreate()
...
private void selectItem(int position) {
Fragment fragment = null;
String fTag = null;
switch (position) {
case 0:
fragment = new FragmentA();
fTag = "fragmentA";
break;
case 1:
fragment = new FragmentC();
fTag = "fragmentC";
break;
case 2:
fragment = new FragmentD();
fTag = "fragmentD";
break;
default:
break;
}
if (fragment != null) {
if(replaceFragments(fragment, fTag)) {
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(mNavigationDrawerItemTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
} else {
Log.e(LOGTAG, "Error in creating fragment");
}
}
public boolean replaceFragments(Fragment fragment, String fTag) {
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment, fTag).addToBackStack(fTag).commit();
return true;
}
@Override
public void onBackPressed() {
int count = fragmentManager.getBackStackEntryCount();
if (count == 0) {
super.onBackPressed();
} else {
getSupportFragmentManager().popBackStack();
//TODO: add app title on count == 1
}
}
最佳答案
创建接口(interface)ValueChangeListener.java
public interface ValueChangeListener {
public void onValueChanged(String value);
}
通过接口(interface)传递值:
public class FragmentB extends Fragment {
private ValueChangeListener valueChangeListener;
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
valueChangeListener = (ValueChangeListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString() + " must implement ValueChangeListener");
}
}
//your code
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(value.getText().toString().trim().length() != 0) {
String order = value.getText().toString();
//now the value is in the Activity and you can pass it anywhere you want from there
valueChangeListener.onValueChanged(order);
}
}
}
实现 Activity 接口(interface):
public class YourActivity extends FragmentActivity implements ValueChangeListener{
@Override
public void onValueChanged(String value) {
//your value is here
}
}
关于java - 从具有值的 fragment B 返回到 fragment A,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26898807/