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在Android中从静态DateDialogFragment中更新活动字段

android-fragments android java

algorhythm · 技术社区 · 6 年前

我正在尝试实现一个 EditText 单击时将显示日期选择器的字段。根据我读到的,一个 DateDialogFragment 被推荐为现代解决方案。

为了简单起见,我从活动中删除了不相关的代码:

public class EditStepCountEntryActivity extends AppCompatActivity
{
    private EditText mChangeDateField;
    private static DateTimeFormatter dateFormat = DateTimeFormatter.ofLocalizedDate(FormatStyle.LONG);

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_step_count_entry);

        initViews();
    }

    private void initViews()
    {
        mChangeDateField = findViewById(R.id.changeDateField);
        mChangeDateField.setInputType(InputType.TYPE_NULL);
        mChangeDateField.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                onChangeDateButtonClicked();
            }
        });
    }

    public void onChangeDateButtonClicked()
    {
        DateDialogFragment datePicker = new DateDialogFragment();
        datePicker.show(getSupportFragmentManager(), "showDate");
    }

    public class DateDialogFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener
    {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState)
        {
            LocalDate date = LocalDate.parse(mStepCountDate.getText(), dateFormat);
            int year = date.getYear();
            int month = date.getMonthValue();
            int day = date.getDayOfMonth();

            return new DatePickerDialog(getActivity(), this, year, month, day);
        }

        public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth)
        {
            showSetDate(LocalDate.of(year, monthOfYear, dayOfMonth));
        }
    }

    public void showSetDate(LocalDate date)
    {
        String dateText = date.format(dateFormat);
        mStepCountDate.setText(dateText);
    }
}

当我点击 编辑文本 我得到以下错误:

JAVAlang.IllegalStateException:片段通用域名格式。实例安卓keepfitapp。EditStepCountEntryActivity。DateDialogFragment 必须是公共静态类才能从实例正确地重新创建状态在androidx。碎片应用程序。零碎的交易。doAddOp(FragmentTransaction.java:249) 在androidx。碎片应用程序。背景记录。doAddOp(backbackrecord.java:180) 在androidx。碎片应用程序。零碎的交易。添加(FragmentTransaction.java:171) 在androidx。碎片应用程序。对话片段。show(DialogFragment.java:174) 在com上。实例安卓keepfitapp。EditStepCountEntryActivity。onChangeDateButtonClicked(EditStepCountEntryActivity.java:187)

错误表明 Fragment 必须是静态的,但是如果 碎片 如果是静态的,我将无法再访问 Activity 编辑文本 .

我可能会把日期传给 碎片 但是我怎样才能把新的日期输入到 活动 ?

0 回复 | 直到 6 年前

Ben 6 年前

嗨,我也有同样的问题。我就是这样解决的:

第一步 让你的活动实现DatePickerDialog。OnDateSetListener(并将其从DialogFragment中删除)。

第二步 ,替换源代码 onCreateDialog 致:

    final Calendar c = Calendar.getInstance();
    int year = c.get(Calendar.YEAR);
    int month = c.get(Calendar.MONTH);
    int day = c.get(Calendar.DAY_OF_MONTH);

    // Activity needs to implement this interface
    DatePickerDialog.OnDateSetListener listener = (DatePickerDialog.OnDateSetListener) getActivity();
    DatePickerDialog q = new DatePickerDialog(getActivity(), listener, year, month, day);
    return q;

第三步 ,在活动 (并将其从DialogFragment中删除)并在设置日期时更新文本字段。

希望它能回答你的问题:)

A. 满的工作示例:(为了便于理解:):

public class MainActivity extends AppCompatActivity  implements DatePickerDialog.OnDateSetListener {
TextView mChangeDateField;
@Override

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mChangeDateField = findViewById(R.id.changeDateField);

}

public void setDateText(View view){
    ClientChooseDateFragment newFragment =
            new ClientChooseDateFragment();
    newFragment.show(getSupportFragmentManager(),
            "datePicker");

}

@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
    mChangeDateField.setText("-- " + year + "--- Month" +month);
}


public static class  ClientChooseDateFragment extends DialogFragment {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();

        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        // Activity needs to implement this interface
        DatePickerDialog.OnDateSetListener listener = (DatePickerDialog.OnDateSetListener) getActivity();
        DatePickerDialog q = new DatePickerDialog(getActivity(), listener, year, month, day);

        return q;
    }
}}