Android的时间选择器

Posted 2023-02-23 志向远大

说到时间选择器，其实就是用到NumberPicker控件。先上效果图，分别是年、月、日、时、分、秒。

1.首先看看布局代码，比较简单就不说了，直接上代码。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context="lovelder.lovcreate.com.dateapplication.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:paddingLeft="10dp"
        android:paddingRight="10dp">

        <NumberPicker
            android:id="@+id/np_year"
            android:layout_width="0dp"
            android:layout_weight="1.3"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content">

        </NumberPicker>
        <NumberPicker
            android:id="@+id/np_month"
            android:layout_width="0dp"
            android:layout_weight="0.8"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content">

        </NumberPicker>
        <NumberPicker
            android:id="@+id/np_day"
            android:layout_width="0dp"
            android:layout_weight="0.8"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content">

        </NumberPicker>
        <NumberPicker
            android:id="@+id/np_hour"
            android:layout_width="0dp"
            android:layout_weight="0.8"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content">

        </NumberPicker>
        <NumberPicker
            android:id="@+id/np_minute"
            android:layout_width="0dp"
            android:layout_weight="0.8"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content">

        </NumberPicker>

    </LinearLayout>

    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="點擊"
        />
</LinearLayout>

2.然后点击“点击按钮”，加载MyCalendarDialog，传入对话框的宽、高、布局、属性。

  btn.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                final MyCalendarDialog dialog = new MyCalendarDialog(MainActivity.this,360,230,R.layout.activity_calendar,R.style.DialogTheme);
                dialog.setSureClick(new MyCalendarDialog.MyCalendar() 
                    @Override
                    public void setCalendar(int year, int month, int day, int hour, int minute) 
                    dialog.dismiss();
                    Toast.makeText(MainActivity.this, year + "年" + month + "月"+ day+ "日" + hour+ "时" + minute + "分", Toast.LENGTH_SHORT).show();
                
            );
                dialog.show();
            
        );

3.分析一下自定义的MyCalendarDialog，设置对话框弹出的宽和高、属性、布局等。

  public MyCalendarDialog(Context context, int width, int height, int layout,
                            int style) 
        super(context, style);
        // 设置内容
        view = LayoutInflater.from(context).inflate(layout,null);
        setContentView(view);
        this.context = context;
        // 设置窗口属性
        Window window = getWindow();
        WindowManager.LayoutParams params = window.getAttributes();
        // 设置宽度、高度、密度、对齐方式
        float density = getDensity(context);
        params.width = (int) (width * density);
        params.height = (int) (height * density);
        params.gravity = Gravity.CENTER;
        window.setAttributes(params);
        initData();
        initView();

    

4.获取当前年、月、日、时、分的值。

 private void initData() 
        Calendar calendar = Calendar.getInstance();
        year = calendar.get(Calendar.YEAR);
        month = calendar.get(Calendar.MONTH) + 1;
        day = calendar.get(Calendar.DAY_OF_MONTH);
        hour = calendar.get(Calendar.HOUR_OF_DAY);
        minute = calendar.get(Calendar.MINUTE);
    

5.设置年的显示格式、最小值、最大值、滑动监听等

   /**
         * 年份
         */
        MyFormatter formatter = new MyFormatter();
        np_year.setFormatter(formatter); //显示格式
        np_year.setMinValue(year); //最小值
        np_year.setMaxValue(5000); //最大值
        np_year.setWrapSelectorWheel(false);//当待显示的条目数大于3时，设置是否可以循环滚动，注意该行应该放在上面三行的下面
        np_year.setOnValueChangedListener(listener);//当值发生改变的监听
        changeValueByOne(np_year, true);//没有这个方法，值增加或者减少的时候会出现异常。

6.但是NumberPicker类的方法是私有，所有无法直接调用。只能通过反射拿到此方法。

  /**
     * Changes the current value by one which is increment or
     * decrement based on the passes argument.
     * decrement the current value.
     *
     * @param increment True to increment, false to decrement.
     */
     private void changeValueByOne(boolean increment) 
        if (mHasSelectorWheel) 
            mInputText.setVisibility(View.INVISIBLE);
            if (!moveToFinalScrollerPosition(mFlingScroller)) 
                moveToFinalScrollerPosition(mAdjustScroller);
            
            mPreviousScrollerY = 0;
            if (increment) 
                mFlingScroller.startScroll(0, 0, 0, -mSelectorElementHeight, SNAP_SCROLL_DURATION);
             else 
                mFlingScroller.startScroll(0, 0, 0, mSelectorElementHeight, SNAP_SCROLL_DURATION);
            
            invalidate();
         else 
            if (increment) 
                setValueInternal(mValue + 1, true);
             else 
                setValueInternal(mValue - 1, true);
            
        
    

7.放射拿到changeValueByOne方法，并执行。

 /**
     * using reflection to change the value because
     * changeValueByOne is a private function and setValue
     * doesn't call the onValueChange listener.
     *
     * @param higherPicker the higher picker
     * @param increment    the increment
     */
    private void changeValueByOne(final NumberPicker higherPicker, final boolean increment) 

        Method method;
        try 
            // refelction call for
            // higherPicker.changeValueByOne(true);
            method = higherPicker.getClass().getDeclaredMethod("changeValueByOne", boolean.class);
            method.setAccessible(true);
            method.invoke(higherPicker, increment);

         catch (final NoSuchMethodException e) 
            e.printStackTrace();
         catch (final IllegalArgumentException e) 
            e.printStackTrace();
         catch (final IllegalAccessException e) 
            e.printStackTrace();
         catch (final InvocationTargetException e) 
            e.printStackTrace();
        
    

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