Android日期时间选择器实现以及自定义大小

本文主要讲两个内容：1.如何将DatePicker和TimePicker放在一个dialog里面；2.改变他们的宽度； 
问题1：其实现思路就是自定义一个Dialog，然后往里面同时放入DatePicker和TimePicker，直接贴代码： 
date_time_picker.xml： 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:orientation="horizontal" >

    <!-- <DatePicker
        android:id="@+id/new_act_date_picker"
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="0.6"
        android:calendarViewShown="false" />

    <TimePicker 
        android:id="@+id/new_act_time_picker"
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="0.3"/> -->
    
    <DatePicker
        android:id="@+id/new_act_date_picker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:calendarViewShown="false" />

    <TimePicker 
        android:id="@+id/new_act_time_picker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

然后在需要显示日期时间选择器的地方（一般是一个onClickListener中）实例化dialog： 
DemoActivity.java 

arriveAtBtn.setOnClickListener(new View.OnClickListener(){  
            @SuppressLint("NewApi")  
            @Override  
            public void onClick(View v) {  
                View view = View.inflate(getApplicationContext(), R.layout.date_time_picker, null);  
                final DatePicker datePicker = (DatePicker)view.findViewById(R.id.new_act_date_picker);  
                final TimePicker timePicker = (TimePicker)view.findViewById(R.id.new_act_time_picker);  
                  
                // Init DatePicker  
                int year;  
                int month;  
                int day;  
                if (StringUtils.isEmpty(arriveDateBtn.getText().toString())) {  
                    // Use the current date as the default date in the picker  
                    final Calendar c = Calendar.getInstance();  
                    year = c.get(Calendar.YEAR);  
                    month = c.get(Calendar.MONTH);  
                    day = c.get(Calendar.DAY_OF_MONTH);  
                } else {  
                    year = NewActActivity.arrive_year;  
                    month = NewActActivity.arrive_month;  
                    day = NewActActivity.arrive_day;  
                }  
                datePicker.init(year, month, day, null);  
                  
                // Init TimePicker  
                int hour;  
                int minute;  
                if (StringUtils.isEmpty(arriveTimeBtn.getText().toString())) {  
                    // Use the current time as the default values for the picker  
                    final Calendar c = Calendar.getInstance();  
                    hour = c.get(Calendar.HOUR_OF_DAY);  
                    minute = c.get(Calendar.MINUTE);  
                } else {  
                    hour = NewActActivity.arrive_hour;  
                    minute = NewActActivity.arrive_min;  
                }  
                timePicker.setIs24HourView(true);  
                timePicker.setCurrentHour(hour);  
                timePicker.setCurrentMinute(minute);  
                  
                // Build DateTimeDialog  
                AlertDialog.Builder builder = new AlertDialog.Builder(NewActActivity.this);  
                builder.setView(view);  
                builder.setTitle(R.string.new_act_date_time_picker_title);  
                builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {  
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        arrive_year = datePicker.getYear();  
                        arrive_month = datePicker.getMonth();  
                        arrive_day = datePicker.getDayOfMonth();  
                        String dateStr = DateUtil.formatDate(arrive_year, arrive_month, arrive_day);  
                        arriveDateBtn.setText(dateStr);  
                          
                        arrive_hour = timePicker.getCurrentHour();  
                        arrive_min = timePicker.getCurrentMinute();  
                        String timeStr = DateUtil.formatTime(arrive_hour, arrive_min);  
                        arriveTimeBtn.setText(timeStr);  
                    }  
                });  
                builder.show();  
            }  
        });  

这样就可以实现日期时间选择器了，这里就有点layout上的小问题，你是需要datepicker和timepicker水平排列还是竖直排列，竖直排列是没问题的：下面给出两个数值排列的效果图： 
（1）DatePicker控件中设置android:calendarViewShown="false" 时的效果图： 

（2）（1）DatePicker控件中设置android:spinnersShown="false" 时的效果图： 

当然，如果你android:calendarViewShown和android:spinnersShown都不设置为false的话，会同时显示日历和滚动条样式，我想一般不会有人想要这样的视图吧。 
水平排列是有问题的，那就是屏幕太挤，两个控件显示不全，看看效果图： 

可是有人就是有水平排列的需求怎么办？这就是本文要讲的第二个问题：改变datepicker和timepicker的宽度。 
网上找了很久，没有发现很有效的方法，说是这两个控件的子元素的宽度是不能自定义的，实际上把控件的所有属性看了一遍，也确实没有发现相关的属性；有人是通过自定义DatePicker和TimePicker来实现的，找了个demo，确实是实现了，不过已经相当于是自己写了一个插件了，我嫌麻烦，加之稳定性方面的考虑，没有去用，不过我会在最后把这个demo的src带上，有需要的人可以自己下载来研究。难道真不能改宽度吗？突然想到我是不是能从代码中的datePicker对象一步步往下找到其child，直接改child的宽度呢，于是debug，果然通过这种方式成功改变了宽度值，代码如下，只要在DemoActivity.java中增加一块专门用于实现改宽度的代码就行： 

DemoActivity.java： 

arriveAtBtn.setOnClickListener(new View.OnClickListener(){
            @SuppressLint("NewApi")
            @Override
            public void onClick(View v) {
                View view = View.inflate(getApplicationContext(), R.layout.date_time_picker, null);
                final DatePicker datePicker = (DatePicker)view.findViewById(R.id.new_act_date_picker);
                final TimePicker timePicker = (TimePicker)view.findViewById(R.id.new_act_time_picker);
                
                // Change DatePicker layout
                LinearLayout dpContainer = (LinearLayout)datePicker.getChildAt(0)    ;    // LinearLayout
                LinearLayout dpSpinner = (LinearLayout)dpContainer.getChildAt(0);        // 0 : LinearLayout; 1 : CalendarView
                for(int i = 0; i < dpSpinner.getChildCount(); i ++) {
                    NumberPicker numPicker = (NumberPicker)dpSpinner.getChildAt(i);        // 0-2 : NumberPicker
                    LayoutParams params1 = new LayoutParams(120, LayoutParams.WRAP_CONTENT);
                    params1.leftMargin = 0;
                    params1.rightMargin = 30;
                    numPicker.setLayoutParams(params1);
                    
//                    EditText cusET = (EditText)numPicker.getChildAt(0);        // CustomEditText
//                    cusET.setTextSize(14);
//                    cusET.setWidth(70);
                }
                
                // Change TimePicker layout
                LinearLayout tpContainer = (LinearLayout)timePicker.getChildAt(0)    ;    // LinearLayout
                LinearLayout tpSpinner = (LinearLayout)tpContainer.getChildAt(0);        // 0 : LinearLayout; 1 : CalendarView
                for(int i = 0; i < tpSpinner.getChildCount(); i ++) {
                    // child(1) is a TextView ( : )
                    if (i == 1) {
                        continue;
                    }
                    NumberPicker numPicker = (NumberPicker)tpSpinner.getChildAt(i);        // 0 : NumberPicker; 1 : TextView; 2 : NumberPicker
                    LayoutParams params3 = new LayoutParams(100, LayoutParams.WRAP_CONTENT);
                    params3.leftMargin = 0;
                    params3.rightMargin = 30;
                    numPicker.setLayoutParams(params3);
                    
//                    EditText cusET = (EditText)numPicker.getChildAt(0);        // CustomEditText
//                    cusET.setTextSize(14);
//                    cusET.setWidth(70);
                }
                
                // Init DatePicker
                int year;
                int month;
                int day;
                if (StringUtils.isEmpty(arriveDateBtn.getText().toString())) {
                    // Use the current date as the default date in the picker
                    final Calendar c = Calendar.getInstance();
                    year = c.get(Calendar.YEAR);
                    month = c.get(Calendar.MONTH);
                    day = c.get(Calendar.DAY_OF_MONTH);
                } else {
                    year = NewActActivity.arrive_year;
                    month = NewActActivity.arrive_month;
                    day = NewActActivity.arrive_day;
                }
                datePicker.init(year, month, day, null);
                
                // Init TimePicker
                int hour;
                int minute;
                if (StringUtils.isEmpty(arriveTimeBtn.getText().toString())) {
                    // Use the current time as the default values for the picker
                    final Calendar c = Calendar.getInstance();
                    hour = c.get(Calendar.HOUR_OF_DAY);
                    minute = c.get(Calendar.MINUTE);
                } else {
                    hour = NewActActivity.arrive_hour;
                    minute = NewActActivity.arrive_min;
                }
                timePicker.setIs24HourView(true);
                timePicker.setCurrentHour(hour);
                timePicker.setCurrentMinute(minute);
                
                // Build DateTimeDialog
                AlertDialog.Builder builder = new AlertDialog.Builder(NewActActivity.this);
                builder.setView(view);
                builder.setTitle(R.string.new_act_date_time_picker_title);
                builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        arrive_year = datePicker.getYear();
                        arrive_month = datePicker.getMonth();
                        arrive_day = datePicker.getDayOfMonth();
                        String dateStr = DateUtil.formatDate(arrive_year, arrive_month, arrive_day);
                        arriveDateBtn.setText(dateStr);
                        
                        arrive_hour = timePicker.getCurrentHour();
                        arrive_min = timePicker.getCurrentMinute();
                        String timeStr = DateUtil.formatTime(arrive_hour, arrive_min);
                        arriveTimeBtn.setText(timeStr);
                    }
                });
                builder.show();
            }
        });

通过这种方式实现的效果图如下： 

其实这种方法也有问题：我的手机是1080P（5.5寸）的屏，显示效果是这样，如果屏幕小点，分辨率更低的屏呢，很可能屏幕宽度不够显示，当然你可以修改一下上面代码的逻辑，根据屏幕大小来动态设置控件的宽度值，而不是设成定值，具体的这些细节按自己的需求来做吧，我这里只是想记录一下自己发现的这种改变datepicker和timepicker宽度的方法，至于是否实用，我不负责，我只当是学习一下android。不过我的项目里最终没有用这个方案，最终选择了垂直排列的日历格式那个方案。 
最后附上别人实现的自定义DatePicker和TimePicker（MyPicker）

MyPicker.rar (120 KB)