如何从选项卡片段创建自定义的警告对话框？

huangapple
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英文:

How to create an custom alertDialog from a tabbed fragment?

问题

问题：

我试图在我的选项卡片段中的按钮按下后打开一个自定义对话框。看起来我的 MainActivity 活动被发送到对话框，但我希望发送我的选项卡片段（GroupFragment），这样我就可以在此片段中更改 editText（暂时）。

代码：

public class GroupFragment extends Fragment implements AddGroupDialog.AddGroupDialogListener {

    private Button addGroupButton;
    private TextView textViewNoGroups;

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

        addGroupButton = view.findViewById(R.id.addGroupButton);
        textViewNoGroups = view.findViewById(R.id.textViewNoGroups);

        addGroupButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                addNewGroupDialog();
            }
        });

        scaleAnimation(addGroupButton);

        return view;
    }

    private void scaleAnimation(View v){
        Animator scale = ObjectAnimator.ofPropertyValuesHolder(v,
                PropertyValuesHolder.ofFloat(View.SCALE_X, 0, 1.2f, 1),
                PropertyValuesHolder.ofFloat(View.SCALE_Y, 0, 1.2f, 1)
        );
        scale.setDuration(600);
        scale.start();
    }

    private void addNewGroupDialog(){
        AddGroupDialog dialog = new AddGroupDialog();
        assert getFragmentManager() != null;
        dialog.show(getFragmentManager(), "add new group dialog");
    }

    @Override
    public void applyString(String groupName) {
        textViewNoGroups.setText(groupName);
    }
}

public class AddGroupDialog extends AppCompatDialogFragment {

    private EditText editTextGroupName;
    private AddGroupDialogListener listener;

    @NonNull
    @Override
    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

        LayoutInflater inflater = getActivity().getLayoutInflater();
        View view = inflater.inflate(R.layout.layout_add_new_group_dialog, null);

        builder.setView(view)
                .setTitle("")
                .setPositiveButton(R.string.confirm, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        String groupName = editTextGroupName.getText().toString();
                        listener.applyString(groupName);
                    }
                });

        editTextGroupName = view.findViewById(R.id.editTextGroupName);
        return builder.create();
    }

    @Override
    public void onAttach(@NonNull Context context) {
        super.onAttach(context);

        try {
            listener = (AddGroupDialogListener) context;
        } catch (ClassCastException e){
            throw new ClassCastException(context.toString() +
                    "Must implement AddGroupDialogListener");
        }
    }

    public interface AddGroupDialogListener{
        void applyString(String groupName);
    }
}

public class MainActivity extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
        ViewPager viewPager = findViewById(R.id.view_pager);
        viewPager.setAdapter(sectionsPagerAdapter);
        TabLayout tabs = findViewById(R.id.tabs);
        tabs.setupWithViewPager(viewPager);
    }
}

public class SectionsPagerAdapter extends FragmentPagerAdapter {

    @StringRes
    private static final int[] TAB_TITLES = new int[]{R.string.tab_text_1, R.string.tab_text_2, R.string.tab_text_3};
    private final Context mContext;

    public SectionsPagerAdapter(Context context, FragmentManager fm) {
        super(fm);
        mContext = context;
    }

    @Override
    public Fragment getItem(int position) {
        Fragment fragment = null;

        switch (position){
            case 0:
                fragment = new GroupFragment();
                break;
            case 1:
                fragment = new AttendanceFragment();
                break;
            case 2:
                fragment = new StatisticsFragment();
                break;
        }
        return fragment;
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return mContext.getResources().getString(TAB_TITLES[position]);
    }

    @Override
    public int getCount() {
        return TAB_TITLES.length;
    }
}

错误：

java.lang.ClassCastException: com.example.attendencetaker.MainActivity@26602bcMust implement AddGroupDialogListener

我希望我对问题的解释是清楚的。谢谢！

英文:

Problem:

I'm trying to open a custom dialog after pressing a button in my tabbed fragment.
It's seems like my MainActivity activity is sent to the dialog while i want my tabbed fragment(GroupFragment) to be sent so i can change the editText(for now) in this fragment.

Code:

       public class GroupFragment extends Fragment implements AddGroupDialog.AddGroupDialogListener {
private Button addGroupButton;
private TextView textViewNoGroups;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_group, container, false);
addGroupButton = view.findViewById(R.id.addGroupButton);
textViewNoGroups = view.findViewById(R.id.textViewNoGroups);
addGroupButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
addNewGroupDialog();
}
});
scaleAnimation(addGroupButton);
return view;
}
private void scaleAnimation(View v){
Animator scale = ObjectAnimator.ofPropertyValuesHolder(v,
PropertyValuesHolder.ofFloat(View.SCALE_X, 0, 1.2f, 1),
PropertyValuesHolder.ofFloat(View.SCALE_Y, 0, 1.2f, 1)
);
scale.setDuration(600);
scale.start();
}
private void addNewGroupDialog(){
AddGroupDialog dialog = new AddGroupDialog();
assert getFragmentManager() != null;
dialog.show(getFragmentManager(), "add new group dialog");
}
@Override
public void applyString(String groupName) {
textViewNoGroups.setText(groupName);
}
}
public class AddGroupDialog extends AppCompatDialogFragment {
private EditText editTextGroupName;
private AddGroupDialogListener listener;
@NonNull
@Override
public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View view = inflater.inflate(R.layout.layout_add_new_group_dialog, null);
builder.setView(view)
.setTitle("")
.setPositiveButton(R.string.confirm, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
String groupName = editTextGroupName.getText().toString();
listener.applyString(groupName);
}
});
editTextGroupName = view.findViewById(R.id.editTextGroupName);
return builder.create();
}
@Override
public void onAttach(@NonNull Context context) {
super.onAttach(context);
try {
listener = (AddGroupDialogListener) context;
} catch (ClassCastException e){
throw new ClassCastException(context.toString() +
"Must implement AddGroupDialogListener");
}
}
public interface AddGroupDialogListener{
void applyString(String groupName);
}
}
public class MainActivity extends AppCompatActivity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
}
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
@StringRes
private static final int[] TAB_TITLES = new int[]{R.string.tab_text_1, R.string.tab_text_2, R.string.tab_text_3};
private final Context mContext;
public SectionsPagerAdapter(Context context, FragmentManager fm) {
super(fm);
mContext = context;
}
@Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch (position){
case 0:
fragment = new GroupFragment();
break;
case 1:
fragment = new AttendanceFragment();
break;
case 2:
fragment = new StatisticsFragment();
break;
}
return fragment;
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
return mContext.getResources().getString(TAB_TITLES[position]);
}
@Override
public int getCount() {
return TAB_TITLES.length;
}
}

Error:

java.lang.ClassCastException: com.example.attendencetaker.MainActivity@26602bcMust implement AddGroupDialogListener

I hope my explanation of the problem is clear. Thank you!

答案1

得分: 0

将活动实现您的接口，然后通过片段上的一个方法将所有数据传递给片段。您将需要一个指向实际显示的片段的引用。

在片段中添加类似于以下内容的方法：

public void updateData(String data) {
    editText.setText(data);
}

然后在活动中的接口覆盖方法中进行如下操作：

@Override
public void update(String data) {
    fragment.updateData(data);
}

更新

改用以下适配器：

public class SectionTabAdapter extends FragmentPagerAdapter {
    
    private ArrayList<Fragment> fragments = new ArrayList<>();
    private ArrayList<String> titles = new ArrayList<>();
    
    public SectionTabAdapter(@NonNull FragmentManager fm, int behavior) {
        super(fm, behavior);
    }
    
    public void addFragment(Fragment fragment, String title) {
        fragments.add(fragment);
        titles.add(title);
    }

    @NonNull
    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return titles.get(position);
    }
}

然后在您的活动中执行以下操作：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    SectionsPagerAdapter sectionTabAdapter = new SectionTabAdapter(this, getSupportFragmentManager());
    Fragment groupFragment = new GroupFragment();
    Fragment attendanceFragment = new AttendanceFragment();
    Fragment statisticsFragment = new StatisticsFragment();
    sectionTabAdapter.addFragment(groupFragment, context.getString(R.string.title_1));
    sectionTabAdapter.addFragment(attendanceFragment, context.getString(R.string.title_2));
    sectionTabAdapter.addFragment(statisticsFragment, context.getString(R.string.title_3));
    ViewPager viewPager = findViewById(R.id.view_pager);
    viewPager.setAdapter(sectionTabAdapter);
    TabLayout tabs = findViewById(R.id.tabs);
    tabs.setupWithViewPager(viewPager);
}
英文:

Make the activity implement your interfaces and so on and then pass all data to the fragment with an method on the fragment. You will need an reference to actual Fragment that is displayed.

In your fragment add a method similar to this:

public void updateData(String data) {
    editText.setText(data);
}

And in the override method of the interface in your activity to this:

@Override
public void update(String data) {
    fragment.updateData(data);
}

Update

Use this Adapter instead:

public class SectionTabAdapter extends FragmentPagerAdapter {
private ArrayList&lt;Fragment&gt; fragments = new ArrayList&lt;&gt;();
private ArrayList&lt;String&gt; titles = new ArrayList&lt;&gt;();
public SectionTabAdapter(@NonNull FragmentManager fm, int behavior) {
super(fm, behavior);
}
public void addFragment(Fragment fragment, String title) {
fragments.add(fragment);
titles.add(title);
}
@NonNull
@Override
public Fragment getItem(int position) {
return fragments.get(position);
}
@Override
public int getCount() {
return fragments.size();
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
}

In your activity then do this:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionTabAdapter = new SectionTabAdapter(this, getSupportFragmentManager());
Fragment groupFragment = new GroupFragment();
Fragment attendanceFragment = new AttendanceFragment();
Fragment statisticsFragment = new StatisticsFragment();
sectionTabAdapter.addFragment(groupFragment, context.getString(R.string.title_1);
sectionTabAdapter.addFragment(attendanceFragment, context.getString(R.string.title_2);
sectionTabAdapter.addFragment(statisticsFragment, context.getString(R.string.title_3);
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionTabAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
}

huangapple
  • 本文由 发表于 2020年8月21日 03:51:40
  • 转载请务必保留本文链接：https://go.coder-hub.com/63512272.html
  • android
  • android-studio
  • java
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