MaterialTimePicker 片段未显示

Question

android 开发新手。我想使用 MaterialTimePicker 从用户那里获取时间输入，并在 TextField 中显示时间。使用 Button 上的 onClickListener 激活 MaterialTimePicker 片段。我也在 java 中开发，我不确定 material.io 网站上的文档是针对 java 还是 kotlin。

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

void timepicker(){
    MaterialTimePicker picker = new MaterialTimePicker.Builder()
            .setTimeFormat(TimeFormat.CLOCK_24H)
            .setTitleText("Select Start Time")
            .setHour(12)
            .setMinute(10)
            .build();
    picker.show(getSupportFragmentManager(), "starttime");
    txtfieldobj.setText(String.valueOf(picker.getHour())+" : "+String.valueOf(picker.getMinute()));
}

错误：目前，当我运行此代码在我单击按钮后出现一秒钟的空白页面，然后它返回到父级 activity。

Answer 1

我试过你的例子，你的问题是你需要删除这一行

txtfieldobj.setText(String.valueOf(picker.getHour())+" : "+String.valueOf(picker.getMinute()));

因为它使应用崩溃

如果你想在点击确定后显示日期和时间，这里是代码：

private final SimpleDateFormat formatter = new SimpleDateFormat("hh:mm a", Locale.getDefault());

    void timepicker() {
        MaterialTimePicker picker = new MaterialTimePicker.Builder()
                .setTimeFormat(TimeFormat.CLOCK_24H)
                .setTitleText("Select Start Time")
                .setHour(12)
                .setMinute(10)
                .build();
        picker.addOnPositiveButtonClickListener(dialog -> {
            int newHour = picker.getHour();
            int newMinute = picker.getMinute();
            DashBoardActivity.this.onTimeSet(newHour, newMinute);
        });
        picker.show(getSupportFragmentManager(), "starttime");
    }

    private void onTimeSet(int newHour, int newMinute) {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.HOUR_OF_DAY, newHour);
        cal.set(Calendar.MINUTE, newMinute);
        cal.setLenient(false);
        String format = formatter.format(cal.getTime());
        txtfieldobj.setText(format);
    }

MaterialTimePicker 片段未显示

MaterialTimePicker fragment not showing up

android

android-timepicker

material-design