前言：

这段时间好久没更新，最近对自定义View感兴趣，先是根据网上的一些例子仿做了一个仿微信通讯录的组合控件，就是那种带字母索引ListView，可惜不知什么原因，用android studio导出的arr包却老是报错，待我继续研究。

后来便搞了这个日历控件，一是对自定义的view感兴趣，二来后来的项目可能需要用到类似的控件，虽说网上也有类似的现成的控件下载，但是觉得自己动手又何尝不是一次联系的机会。

先上图

normal

日期单选

日期多选

由于不会上传视频，只能截图啦

自定义View的过程也不重复太多，毕竟网上这么多教程了

就总结一下流程吧

新建一个类继承于View或者View的子类

实现三个构造方法

可以在value目录下新建attrs.xml文件，再其中声明以及内部的子标签来定义xml属性。

实现onMeasure()方法以及最重要的onDraw()方法

因为是自定义的日历控件，所以我也重写了dispatchTouchEvent()方法来解决响应事件。

思路：

要绘制出一个月的日历，需要下列几个参数

这个月的天数

这个月第一天是星期几

今天是几号

手画的，见谅

贴上最重要的onDraw()方法

protected void onDraw(Canvas canvas) {

//绘制背景色

canvas.drawColor(mBackground);

//绘制左箭头

mNumPaint.setColor(clickLeft ? mNormalButtonColor1 : mClickButtonColor2);

mNumPaint.setStrokeWidth(6);

mNumPaint.setAntiAlias(true);

canvas.drawLine(mViewWidth / 8, mViewHeight / 16, mViewWidth * 3 / 16, mViewHeight / 32, mNumPaint);

canvas.drawLine(mViewWidth / 8, mViewHeight / 16, mViewWidth * 3 / 16, mViewHeight * 3 / 32, mNumPaint);

mNumPaint.reset();

//绘制右箭头

mNumPaint.setColor(clickRight ? mNormalButtonColor1 : mClickButtonColor2);

mNumPaint.setStrokeWidth(6);

mNumPaint.setAntiAlias(true);

canvas.drawLine(mViewWidth * 7 / 8, mViewHeight / 16,

mViewWidth * 13 / 16, mViewHeight / 32, mNumPaint);

canvas.drawLine(mViewWidth * 7 / 8, mViewHeight / 16,

mViewWidth * 13 / 16, mViewHeight * 3 / 32, mNumPaint);

mNumPaint.reset();

//绘制年，月份

mNumPaint.setTextSize(mViewHeight / 16);

mNumPaint.setColor(mNormalTextColor1);

mNumPaint.setAntiAlias(true);

String theYear = year + "";

String theMonth = month + "";

canvas.drawText(theYear, mViewWidth / 2 - getTextWidth(mNumPaint, theYear) / 2,

mViewHeight / 16, mNumPaint);

mNumPaint.setTextSize(mViewHeight / 18);

mNumPaint.setColor(mNormalTextColor2);

canvas.drawText(theMonth, mViewWidth / 2 - getTextWidth(mNumPaint, theMonth) / 2,

mViewHeight / 8, mNumPaint);

mNumPaint.reset();

//绘制日历

xInterval = mViewWidth / 7;

yInterval = mViewHeight / 8;

int day = 0;

float x;

float y;

int theday;

boolean isToday = false;

boolean isCheckDay = false;

float offset = 0;

radius = mViewWidth / 19;

for (int i = 0; i < weekName.length; i++) {

x = i * xInterval + mNormalTextSize / 2;

y = 1 * yInterval + yInterval / 2;

if (i == 0 || i == weekName.length - 1) {

drawNum(weekName[i], mNormalTextSize, mNormalTextColor2, x, y,

canvas, isToday, offset);

} else {

drawNum(weekName[i], mNormalTextSize, mNormalTextColor1, x, y,

canvas, isToday, offset);

}

}

mNumPaint.reset();

String str;

for (int i = 2; i < 8; i++) {

for (int j = 0; j < 7; j++) {

if (i == 2 && j == 0) {

j = weekOfFirstDay;

}

if (day > allDays.length - 1) {

theday = -1;

} else {

theday = allDays[day];

}

str = "" + theday;

if (theday == -1) {

str = "";

}

//单个数字的偏移量

if (theday < 10 && theday > 0) {

offset = mNormalTextSize / 4;

}

//计算数字的位置

y = i * yInterval + yInterval / 2;

x = j * xInterval + mNormalTextSize / 2 -

getTextWidth(mNumPaint, str) + offset;

//判断是否为今天

isToday = theday == today;

if (isToday) {

drawACircle(x, y, Color.argb(255, 254, 140, 26),

radius, canvas, offset);

}

//如果数字是checkDay

isCheckDay = theday == firstCheckDay;

if (isCheckDay) {

drawACircle(x, y, 0xffa0c8c8, radius, canvas, offset);

}

if (secondCheckDay != -2) {

if (theday > firstCheckDay && theday <= secondCheckDay) {

drawACircle(x, y, 0xffa0c8c8, radius, canvas, offset);

isCheckDay = true;

}

}

if (j == 0 || j == 6) {

drawNum(str, mNormalTextSize, mNormalTextColor2,

x, y, canvas, isToday || isCheckDay, offset);

} else {

drawNum(str, mNormalTextSize, mNormalTextColor1,

x, y, canvas, isToday || isCheckDay, offset);

}

offset = 0;

day++;

mNumPaint.reset();

}

}

}

再贴上dispatchTouchEvent()方法

public boolean dispatchTouchEvent(MotionEvent event) {

//获取事件的位置

float touchX = event.getX();

float touchY = event.getY();

if (!canClick) {

return true;

}

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

if (touchY < 3 * mViewHeight / 32 && touchY > mViewHeight / 32) {

if (touchX < 3 * mViewWidth / 16 && touchX > mViewWidth / 8) {

clickLeft = true;

//左箭头事件

if (turnPageListener != null) {

turnPageListener.OnLeftDown(today, month, year);

}

}

if (touchX < 7 * mViewWidth / 8 && touchX > 13 * mViewWidth / 16) {

clickRight = true;

//右箭头事件

if (turnPageListener != null) {

turnPageListener.OnRightUp(today, month, year);

}

}

}

//以下是对日历的事件处理

int theX = (int) ((touchX + 0.1 * xInterval) / xInterval);//获取第几列

int theY = (int) ((touchY + 0.2 * yInterval) / yInterval);//获取第几行

if (theY < 2) {

theY = 2;

}

//得到是哪一天

int num = (theY - 2) * 7 + theX - weekOfFirstDay;

int day;

if (num < 0 || num > allDays.length - 1) {

num = -2;

day = 0;

} else {

day = allDays[num];

}

float x = theX * xInterval + mNormalTextSize / 2 -

mNumPaint.measureText("" + day);

float y = theY * yInterval + yInterval / 2;

//判断是否点击在每个数字为中心的圆内

boolean isclick = isClick(x, y, num, touchX, touchY);

//有三种状态 初始状态(00)，第一次点击(10)，第二次点击(11)

if (!firstClick) {

firstClick = true;

} else if (!secondClick) {

secondClick = true;

} else {

firstClick = false;

secondClick = false;

firstCheckDay = -2;

secondCheckDay = -2;

}

//处理点击在月份天数外所引起的数值问题

if (isclick && num != -2 && firstClick && !secondClick) {

firstCheckDay = allDays[num];

}

if (firstClick && firstCheckDay == -2) {

firstClick = false;

}

if (isclick && num != -2 && secondClick) {

if (allDays[num] < firstCheckDay) {

firstCheckDay = allDays[num];

secondClick = false;

} else {

secondCheckDay = allDays[num];

}

}

if (secondClick && secondCheckDay == -2) {

secondClick = false;

}

//

//调用接口

if (firstClick && !secondClick) {

if (chooseListener != null) {

chooseListener.onSingleChoose(firstCheckDay);

}

} else if (firstClick && secondClick) {

int numO = secondCheckDay - firstCheckDay + 1;

int[] days = new int[numO];

int tday = firstCheckDay;

for (int j = 0; j < numO; j++) {

days[j] = tday++;

}

if (chooseListener != null) {

chooseListener.onDoubleChoose(days);

}

}

break;

case MotionEvent.ACTION_UP:

//左箭头事件

if (clickLeft) {

if (turnPageListener != null) {

turnPageListener.OnLeftUp(today, month, year);

}

clickLeft = !clickLeft;

preMonth();

}

//右箭头事件

if (clickRight) {

if (turnPageListener != null) {

turnPageListener.OnRightUp(today, month, year);

}

clickRight = !clickRight;

nextMonth();

}

break;

}

invalidate();

return true;

}

待完善的地方

日期的多选还没做到跨月

没有做动画

发现在对日期的绘制位置的计算出了偏差，待下次更新！