实现步骤:
1、实现一个滑动选择器
2、自定义需要的布局
3、为布局插入需要的数据,调用自定义滑动日历选择控件
效果:
详解:
1、实现一个滑动选择器
声明:这个滑动选择器是网上淘的,但现在没找到原创,如有疑议,可以留言
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Align;
import android.graphics.Paint.FontMetricsInt;
import android.graphics.Paint.Style;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
/**
* Created by Administrator on 2018/1/16 0016.
* 视图选择器(滚动选择--日期、地区)定义滑动效果
*/
public class CalendarView extends View {
public static final String TAG = "CalendarView";
/**
* text之间间距和minTextSize之比
*/
public static final float MARGIN_ALPHA = 2.8f;
/**
* 自动回滚到中间的速度
*/
public static final float SPEED = 2;
private List<String> mDataList;
/**
* 选中的位置,这个位置是mDataList的中心位置,一直不变
*/
private int mCurrentSelected;
private Paint mPaint;
private float mMaxTextSize = 80;
private float mMinTextSize = 40;
private float mMaxTextAlpha = 255;
private float mMinTextAlpha = 120;
private int mColorText = 0x333333;
private int mViewHeight;
private int mViewWidth;
private float mLastDownY;
/**
* 滑动的距离
*/
private float mMoveLen = 0;
private boolean isInit = false;
private onSelectListener mSelectListener;
private Timer timer;
private MyTimerTask mTask;
Handler updateHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (Math.abs(mMoveLen) < SPEED) {
mMoveLen = 0;
if (mTask != null) {
mTask.cancel();
mTask = null;
performSelect();
}
} else
// 这里mMoveLen / Math.abs(mMoveLen)是为了保有mMoveLen的正负号,以实现上滚或下滚
mMoveLen = mMoveLen - mMoveLen / Math.abs(mMoveLen) * SPEED;
invalidate();
}
};
public CalendarView(Context context) {
super(context);
init();
}
public CalendarView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public void setOnSelectListener(onSelectListener listener) {
mSelectListener = listener;
}
private void performSelect() {
if (mSelectListener != null)
mSelectListener.onSelect(mDataList.get(mCurrentSelected));
}
public void setData(List<String> datas) {
mDataList = datas;
mCurrentSelected = datas.size()/2;
invalidate();
}
public void setSelected(int selected) {
mCurrentSelected = selected;
}
private void moveHeadToTail() {
String head = mDataList.get(0);
mDataList.remove(0);
mDataList.add(head);
}
private void moveTailToHead() {
String tail = mDataList.get(mDataList.size() - 1);
mDataList.remove(mDataList.size() - 1);
mDataList.add(0, tail);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mViewHeight = getMeasuredHeight();
mViewWidth = getMeasuredWidth();
// 按照View的高度计算字体大小
mMaxTextSize = mViewHeight / 4.0f;
mMinTextSize = mMaxTextSize / 2f;
isInit = true;
invalidate();
}
private void init() {
timer = new Timer();
mDataList = new ArrayList<String>();
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setStyle(Style.FILL);
mPaint.setTextAlign(Align.CENTER);
mPaint.setColor(mColorText);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 根据index绘制view
if (isInit)
drawData(canvas);
}
private void drawData(Canvas canvas) {
// 先绘制选中的text再往上往下绘制其余的text
float scale = parabola(mViewHeight / 4.0f, mMoveLen);
float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;
mPaint.setTextSize(size);
mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));
// text居中绘制,注意baseline的计算才能达到居中,y值是text中心坐标
float x = (float) (mViewWidth / 2.0);
float y = (float) (mViewHeight / 2.0 + mMoveLen);
FontMetricsInt fmi = mPaint.getFontMetricsInt();
float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));
canvas.drawText(mDataList.get(mCurrentSelected), x, baseline, mPaint);
// 绘制上方data
for (int i = 1; (mCurrentSelected - i) >= 0; i++) {
drawOtherText(canvas, i, -1);
}
// 绘制下方data
for (int i = 1; (mCurrentSelected + i) < mDataList.size(); i++) {
drawOtherText(canvas, i, 1);
}
}
/**
* @param canvas
* @param position
* 距离mCurrentSelected的差值
* @param type
* 1表示向下绘制,-1表示向上绘制
*/
private void drawOtherText(Canvas canvas, int position, int type) {
float d = (float) (MARGIN_ALPHA * mMinTextSize * position + type
* mMoveLen);
float scale = parabola(mViewHeight / 4.0f, d);
float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;
mPaint.setTextSize(size);
mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));
float y = (float) (mViewHeight / 2.0 + type * d);
FontMetricsInt fmi = mPaint.getFontMetricsInt();
float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));
canvas.drawText(mDataList.get(mCurrentSelected + type * position),
(float) (mViewWidth / 2.0), baseline, mPaint);
}
/**
* 抛物线
*
* @param zero
* 零点坐标
* @param x
* 偏移量
* @return scale
*/
private float parabola(float zero, float x) {
float f = (float) (1 - Math.pow(x / zero, 2));
return f < 0 ? 0 : f;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
doDown(event);
break;
case MotionEvent.ACTION_MOVE:
doMove(event);
break;
case MotionEvent.ACTION_UP:
doUp(event);
break;
}
return true;
}
private void doDown(MotionEvent event) {
if (mTask != null) {
mTask.cancel();
mTask = null;
}
mLastDownY = event.getY();
}
private void doMove(MotionEvent event) {
mMoveLen += (event.getY() - mLastDownY);
if (mMoveLen > MARGIN_ALPHA * mMinTextSize / 2) {
// 往下滑超过离开距离
moveTailToHead();
mMoveLen = mMoveLen - MARGIN_ALPHA * mMinTextSize;
} else if (mMoveLen < -MARGIN_ALPHA * mMinTextSize / 2) {
// 往上滑超过离开距离
moveHeadToTail();
mMoveLen = mMoveLen + MARGIN_ALPHA * mMinTextSize;
}
mLastDownY = event.getY();
invalidate();
}
private void doUp(MotionEvent event) {
// 抬起手后mCurrentSelected的位置由当前位置move到中间选中位置
if (Math.abs(mMoveLen) < 0.0001) {
mMoveLen = 0;
return;
}
if (mTask != null) {
mTask.cancel();
mTask = null;
}
mTask = new MyTimerTask(updateHandler);
timer.schedule(mTask, 0, 10);
}
class MyTimerTask extends TimerTask {
Handler handler;
public MyTimerTask(Handler handler) {
this.handler = handler;
}
@Override
public void run() {
handler.sendMessage(handler.obtainMessage());
}
}
public interface onSelectListener {
void onSelect(String text);
}
}
实现原理的话自己研究吧
2、自定义需要的布局
布局可以根据自己需要来,我的是这样的
<?xml version="1.0" encoding="utf-8"?>
<!--滑动选择日历的布局-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/customDialog"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="20dp"
android:paddingBottom="20dp"
android:gravity="center"
android:textColor="#000000"
android:textSize="20sp"
android:text="选择日期"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<com.win.customview.slide_calendar.CalendarView
android:id="@+id/year"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="100dp"/>
<com.win.customview.slide_calendar.CalendarView
android:id="@+id/month"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="100dp"/>
<com.win.customview.slide_calendar.CalendarView
android:id="@+id/day"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="100dp"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
这个就是上面的滑动视图选择器 com.win.customview.slide_calendar.CalendarView
因为有年月日,所以就有三个滑动视图选择器
可根据自己的需要改变布局,如每个选择器后面加上 年、月、日 之类的字
3、为布局插入需要的数据,调用自定义滑动日历选择控件
为布局插入数据可以在用的时候写个方法将数据插入,调用时调用方法就好了
以下是具体代码
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import com.win.customview.R;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
//弹出一个弹框,通过滑动选择日历日期
public class SlideCalendarActivity extends AppCompatActivity {
private TextView data;//日期数据显示
private Button data_base;//通过滑动日历选择
private CalendarView calendarView1,calendarView2,calendarView3;
//没有选择时,将会显示的日期,也可以根据系统获取当前时间
private String years = "2018",months = "3", days = "13";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_slide_calendar);
data = (TextView)findViewById(R.id.data);
data_base = (Button)findViewById(R.id.data_base);
data_base.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//点击弹出滑轮选择日历控件
myCalendar();
}
});
}
public void myCalendar(){
//初始化对话框 R.style.CalendarDialog 是自定义的弹框主题,在styles设置
final AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.CalendarDialog);
//初始化自定义布局参数
LayoutInflater layoutInflater = getLayoutInflater();
//绑定布局
View customLayout = layoutInflater.inflate(R.layout.view_slide_calendar, (ViewGroup) findViewById(R.id.customDialog));
//为对话框设置视图
builder.setView(customLayout);
//加载年月日的三个 CalendarView 的 id
calendarView1 = (CalendarView) customLayout.findViewById(R.id.year);
calendarView2 = (CalendarView) customLayout.findViewById(R.id.month);
calendarView3 = (CalendarView) customLayout.findViewById(R.id.day);
//定义滚动选择器的数据项(年月日的)
ArrayList<String> gradeYear = new ArrayList<>();
ArrayList<String> gradeMonth = new ArrayList<>();
ArrayList<String> gradeDay = new ArrayList<>();
//为数据项赋值
int thisYear = Integer.parseInt(new SimpleDateFormat("yyyy").format(new java.util.Date()));
for(int i=1980;i<=thisYear;i++) //从1980到今年
gradeYear.add(i + "");
for(int i=1;i<=12;i++) // 1月到12月
gradeMonth.add(i + "");
for(int i=1;i<=31;i++) // 1日到31日
gradeDay.add(i + "");
//为滚动选择器设置数据
calendarView1.setData(gradeYear);
calendarView2.setData(gradeMonth);
calendarView3.setData(gradeDay);
//滚动选择事件
calendarView1.setOnSelectListener(new CalendarView.onSelectListener() {
@Override
public void onSelect(String data) {
years = data;
}
});
calendarView2.setOnSelectListener(new CalendarView.onSelectListener() {
@Override
public void onSelect(String data) {
months = data;
}
});
calendarView3.setOnSelectListener(new CalendarView.onSelectListener() {
@Override
public void onSelect(String data) {
days = data;
}
});
//对话框的确定按钮
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
data.setText(years + " 年 "+ months + " 月 " + days + " 日 ");
}
});
//对话框的取消按钮
builder.setNegativeButton("取消", null);
//显示对话框
builder.show();
}
}
注意,在 myCalendar() 方法 中通过绑定布局、根据 id 为每一个视图选择器赋值,
根据滚动选择事件获得选择的数据,将数据赋予定义的变量,这样就能够获取到数据了
我们可以看到,赋予的值都是数字,但是是通过 add() 赋予的,这时,我们应该想到,
是否字符串也能够实现滚动选择呢? 是的 如果你把数据放到数组中,
通过 for 循环赋值给滚动选择器,这时,被选择的就可以是文字了,如下图示:
不过要改成这样的,那么前面的省份改变时,后面的 市级 也需要对应更改,这就需要你们自己研究一下喽
源码:https://github.com/iscopy/CustomView
在 slide_calendar 包里面