Android自定义View第三弹（反人类尺子）
都说尺子很好写，但是反人类的尺子也不好写，吐槽下产品（此处省略1000字），为啥说反人类呢，因为数字在上刻度在下，有没有很反人类，好吧，你说没有，那是因为你看了我的文章。
废话不多说，先上图：
一.给你个自定义View代码
public class Ruler extends View {
private final int VERTICAL=0;
private final int HORIZONTAL=1;
//间隔，即两条刻度之间的距离
private int interval;
//起始值
private int fromValue;
//结束值
private int toValue;
//每两个值之间的间隔数,也指多少个最小单位，比如0cm到1cm有10个最小单位1mm
private int intervalsBetweenValues;
//相邻两个值的跳跃间隔，如上面第一张图的10000到11000，中间的跳跃值就是1000
private int valuesInterval;
//当前值
private int currentValue;
//值的文本大小
private int valuesTextSize;
//值的文本颜色
private int valuesTextColor;
//刻度的宽度
private int linesWidth;
//刻度的颜色
private int linesColor;
//刻度尺是vertical还是horizontal,上面第一张图的就是horizontal
private int orientation;
private Paint paint;
private OnValueChangeListener listener;
private int currentPosition;
private int textHeight;
private int offset;
private int oldX;
private int oldY;
public Ruler(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
// TODO Auto-generated constructor stub
TypedArray array=context.obtainStyledAttributes(attrs, R.styleable.Ruler);
interval=array.getDimensionPixelSize(R.styleable.Ruler_interval, dp2px(intervalsBetweenValues));
fromValue=array.getInt(R.styleable.Ruler_fromValue, 0);
toValue=array.getInt(R.styleable.Ruler_toValue, intervalsBetweenValues);
currentValue=array.getInt(R.styleable.Ruler_currentValue, (fromValue+toValue)/2);
intervalsBetweenValues=array.getInt(R.styleable.Ruler_intervalsBetweenValues, intervalsBetweenValues);
valuesInterval=array.getInt(R.styleable.Ruler_valuesInterval, 1);
valuesTextSize=array.getDimensionPixelSize(R.styleable.Ruler_valuesTextSize, sp2px(16));
valuesTextColor=array.getColor(R.styleable.Ruler_valuesTextColor, Color.BLACK);
linesWidth=array.getDimensionPixelSize(R.styleable.Ruler_linesWidth, dp2px(1));
linesColor=array.getColor(R.styleable.Ruler_linesColor, Color.BLACK);
orientation=array.getInt(R.styleable.Ruler_orientation, HORIZONTAL);
array.recycle();
paint=new Paint();
paint.setTextSize(valuesTextSize);
//文本高度
FontMetrics fm=paint.getFontMetrics();
textHeight=(int)(fm.bottom-fm.top);
//当前所指的刻度位置，即中间红色指针指向的值
currentPosition=currentValue/valuesInterval*intervalsBetweenValues;
}
public Ruler(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
}
public Ruler(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
if(orientation==VERTICAL){
//画中间的指针,就在中间画，很简单
paint.setColor(getResources().getColor(R.color.colorGreen));
paint.setStrokeWidth(dp2px(2));
canvas.drawLine(getWidth(), getHeight()/2, getWidth()/4, getHeight()/5, paint);
//刻度线分两部分画，一半是上部分，一半是下部分
//画中间以上部分的刻度
paint.setColor(linesColor);
paint.setStrokeWidth(linesWidth);
int height=getHeight()/2+offset;
int position=currentPosition;
//循环画刻度，当画到上边界或起始值时则退出循环，去画下半部分刻度
while(true){
//intervalsBetweenValues/2是指两个相邻值之间距离的中间那条稍微长一点的刻度的位置
if(position%(intervalsBetweenValues/2)==0){
//当刻度值的位置为刻度值旁边的时候则画长一点，并在旁边画上数字，否则就按普通刻度长度画
if(position%intervalsBetweenValues==0){
canvas.drawLine(getWidth(), height, getWidth()/2, height, paint);
String valueString=Integer.toString(position/intervalsBetweenValues*valuesInterval);
paint.setColor(valuesTextColor);
canvas.drawText(valueString, getWidth()/2-paint.measureText(valueString)-dp2px(5), height+textHeight/3, paint);
paint.setColor(linesColor);
}else{
canvas.drawLine(getWidth(), height, getWidth()*3/5, height, paint);
}
}else{
canvas.drawLine(getWidth(), height, getWidth()*4/5, height, paint);
}
//每画完一条刻度则递减position和height,当position=起始值，或height低于0，即超出边界时，退出循环
position--;
if(positionbreak;
height-=interval;
if(height<0-textHeight) break;
}
//画中间以下部分的刻度，和画上半部同理
height=getHeight()/2+offset;
position=currentPosition;
while(true){
position++;
if(position>toValue/valuesInterval*intervalsBetweenValues) break;
height+=interval;
if(height>getHeight()+textHeight) break;
if(position%(intervalsBetweenValues/2)==0){
if(position%intervalsBetweenValues==0){
canvas.drawLine(getWidth(), height, getWidth()/2, height, paint);
String valueString=Integer.toString(position/intervalsBetweenValues*valuesInterval);
paint.setColor(valuesTextColor);
canvas.drawText(valueString, getWidth()/2-paint.measureText(valueString)-dp2px(5), height+textHeight/3, paint);
paint.setColor(linesColor);
}else{
canvas.drawLine(getWidth(), height, getWidth()*3/5, height, paint);
}
}else{
canvas.drawLine(getWidth(), height, getWidth()*4/5, height, paint);
}
}
}else{
//画中间的指针
paint.setColor(getResources().getColor(R.color.colorGreen));
paint.setStrokeWidth(dp2px(2));
canvas.drawLine(getWidth()/2, getHeight(), getWidth()/2, getHeight()/5, paint);
//画中间左边部分的刻度
paint.setColor(linesColor);
paint.setStrokeWidth(linesWidth);
int width=getWidth()/2+offset;
int position=currentPosition;
while(true){
if(position%(intervalsBetweenValues/2)==0){
if(position%intervalsBetweenValues==0){
canvas.drawLine(width, getHeight(), width, getHeight()/2, paint);
String valueString=Integer.toString(position/intervalsBetweenValues*valuesInterval);
paint.setColor(valuesTextColor);
canvas.drawText(valueString, width-paint.measureText(valueString)/2, getHeight()/2-textHeight/2, paint);
paint.setColor(linesColor);
}else{
canvas.drawLine(width, getHeight(), width, getHeight()*3/5, paint);
}
}else{
canvas.drawLine(width, getHeight(), width, getHeight()*4/5, paint);
}
position--;
if(positionbreak;
width-=interval;
//这里需要额外加上以文本“10000”的长度作为偏移量，防止值文本很长的时候，文本还没完全退出边界就消失了
if(width<0-paint.measureText("10000")) break;
}
//画中间右边部分的刻度
width=getWidth()/2+offset;
position=currentPosition;
while(true){
position++;
if(position>toValue/valuesInterval*intervalsBetweenValues) break;
width+=interval;
if(width>getWidth()+paint.measureText("10000")) break;
if(position%(intervalsBetweenValues/2)==0){
if(position%intervalsBetweenValues==0){
canvas.drawLine(width, getHeight(), width, getHeight()/2, paint);
String valueString=Integer.toString(position/intervalsBetweenValues*valuesInterval);
paint.setColor(valuesTextColor);
canvas.drawText(valueString, width-paint.measureText(valueString)/2, getHeight()/2-textHeight/2, paint);
paint.setColor(linesColor);
}else{
canvas.drawLine(width, getHeight(), width, getHeight()*3/5, paint);
}
}else{
canvas.drawLine(width, getHeight(), width, getHeight()*4/5, paint);
}
}
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//记录初始位置
if(orientation==HORIZONTAL){
oldX=(int)event.getX();
}else{
oldY=(int)event.getY();
}
break;
case MotionEvent.ACTION_MOVE:
if(orientation==HORIZONTAL){
//滑动的距离
offset=(int)(event.getX()-oldX);
//滑动的距离除以每个刻度间隔，得出滑动了多少个间隔，即在相应的刻度position上加上或减去该间隔数
if(Math.abs(offset)>=interval){
currentPosition-=offset/interval;
if(currentPosition>toValue/valuesInterval*intervalsBetweenValues)
currentPosition=toValue/valuesInterval*intervalsBetweenValues;
if(currentPosition//记录好当前的偏移位置作为下次滑动偏移量的起始位置oldX
oldX=(int)event.getX();
}
//取余算好不够一个间隔的偏移量，用于ACTION_UP计算四舍五入
offset%=interval;
}else{
//同HORIZONTAL模式
offset=(int)(event.getY()-oldY);
if(Math.abs(offset)>=interval){
currentPosition-=offset/interval;
if(currentPosition>toValue/valuesInterval*intervalsBetweenValues)
currentPosition=toValue/valuesInterval*intervalsBetweenValues;
if(currentPositionint)event.getY();
}
offset%=interval;
}
//重绘，达到滑动动画效果
invalidate();
if(listener!=null){
//通过一个接口将数据暴露出去
listener.onValueChange(currentPosition*valuesInterval/intervalsBetweenValues);
}
break;
case MotionEvent.ACTION_UP:
//根据offset处理，若大于间隔的一半，那么+1，否则-1
if(offset>0 && offset>interval/2){
currentPosition--;
if(currentPositionelse if(offset<0 && Math.abs(offset)>interval/2){
currentPosition++;
if(currentPosition>toValue/valuesInterval*intervalsBetweenValues){
currentPosition=toValue/valuesInterval*intervalsBetweenValues;
}
}
//偏移量置0
offset=0;
invalidate();
if(listener!=null){
//通过一个接口将数据暴露出去
listener.onValueChange(currentPosition*valuesInterval/intervalsBetweenValues);
}
break;
}
return true;
}
private int sp2px(int sp){
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp, getResources().getDisplayMetrics());
}
private int dp2px(int dp){
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, getResources().getDisplayMetrics());
}
public void setOnValueChangeListener(OnValueChangeListener listener){
this.listener=listener;
}
public void setValue(int value){
currentPosition=value/valuesInterval*intervalsBetweenValues;
invalidate();
}
public void setFromValue(int fromValue){
this.fromValue=fromValue;
invalidate();
}
public void setToValue(int toValue){
this.toValue=toValue;
invalidate();
}
} 二.给你个attr.xml
三.给你个原谅色
#19CA89
四.给你个用法
Ruler ruler_shuzhang;
//记得findViewById();
ruler.setOnValueChangeListener(new OnValueChangeListener() {
@Override
public void onValueChange(int value) {
tv_pressure_1.setText(value+"");
diastolicPressure=value;
}
});五.给你个布局
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<RelativeLayout
android:id="@+id/rl_rule1"
android:layout_width="350dp"
android:layout_height="60dp"
android:layout_marginTop="5dp"
android:layout_below="@id/ll_edit_1"
android:layout_centerHorizontal="true"
android:background="@drawable/shape_ruler">
<com.****.*****.widgets.Ruler
android:id="@+id/ruler_shuzhang"
android:layout_width="345dp"
android:layout_height="55dp"
android:layout_centerInParent="true"
android:background="#ffffff"
custom:fromValue="30"
custom:interval="5dp"
custom:intervalsBetweenValues="10"
custom:linesColor="#33000000"
custom:linesWidth="4px"
custom:toValue="150"
custom:valuesInterval="10"
custom:valuesTextSize="12sp" />
RelativeLayout>
LinearLayout>六.给你个Shape，具有美颜效果的Shape : shape_ruler.xml
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
<corners android:radius="5dp"/>
<stroke android:width="1dp" android:color="#999999"/>
<solid android:color="#ffffff"/>
shape>哈哈，好看的尺子给你了，点个赞呗，求五星好评