我想将区域更改为最大溢出：仅在支持::-webkit-scrollbar-thumb时滚动。
这在纯CSS中是否有可能？看起来@supports只检查规则，没有选择器。
答案 0 :(得分：4)
你是对的。 public class MatchNutsBolts {
public static void main(String[] args) {
// TODO Auto-generated method stub
Random r = new Random(20);
Bolt[] listOfBolts = NutsBolts.makeRandomBolts(r, 7);
Nut[] listOfNuts = NutsBolts.makeMatchingNuts(r, listOfBolts);
int low = 0;
int hi = listOfBolts.length-1;
match(listOfNuts, listOfBolts, low, hi);
boolean x = NutsBolts.correctFit(listOfNuts, listOfBolts);
System.out.print(x+" ");
}
public static void match(Nut[] nut, Bolt[] bolt, int low, int hi)
{
if (low < hi)
{
// Choose last character of bolts array for nuts partition.
int pivot = partition(nut, low, hi, bolt[hi]); //here is where im having a problem
// Now using the partition of nuts choose that for bolts
// partition.
partition(bolt, low, hi, nut[pivot]);
match(nut, bolt, low, pivot-1);
match(nut, bolt, pivot+1, hi);
}
}
private static int partition(Bolt[] bolt, int low, int high, Nut pivot)
{
int i = low;
Bolt temp1, temp2;
for (int j = low; j < high; j++)
{
//int cmp = Nut.compareTo(bolt[j]);
if (bolt[j].getDigit(i) < pivot.getDigit(i)){
temp1 = bolt[i];
bolt[i] = bolt[j];
bolt[j] = temp1;
i++;
} else if(bolt[j].getDigit(i) == pivot.getDigit(i)){
temp1 = bolt[j];
bolt[j] = bolt[high];
bolt[high] = temp1;
j--;
}
}
temp2 = bolt[i];
bolt[i] = bolt[high];
bolt[high] = temp2;
// Return the partition index of an array based on the pivot
// element of other array.
return i;
}
}
class Bolt {
final private static int SIZE = 7;
private int[] notches;
// A Bolt object is basically a seven digit number.
public Bolt(Random r) {
notches = new int[SIZE];
for (int i=0; i<notches.length; i++)
notches[i] = r.nextInt(10);
}
// A standard constructor given the information stored in a Bolt.
public Bolt(int[] digits) {
notches = new int[digits.length];
for (int i=0; i<SIZE; i++)
notches[i] = digits[i];
}
// Needed to access each digit of a Bolt.
public int getDigit(int i) {
return notches[i];
}
// Made this work the opposite of the corresponding comparison. Surprisingly
// it's not a circular definition, just a consistent one.
public int compareTo(Nut n) {
return -n.compareTo(this);
}
// Return a matching Nut. A matching nut is one who's number has each digit
// be its complement. A complement to a digit is its difference from 9.
public Nut getMatchingNut() {
int[] tmp = new int[SIZE];
// We set each digit for the match.
for (int i=0; i<SIZE; i++)
tmp[i] = 9 - notches[i];
// Now create the object and return it.
Nut match = new Nut(tmp);
return match;
}
// For debugging purposes.
/*public void print() {
for (int i=0; i<SIZE; i++)
System.out.print(notches[SIZE-1-i]);
}*/
}
class Nut {
final private static int SIZE = 7;
private int[] notches;
// A Nut object is basically a seven digit number.
public Nut(Random r) {
notches = new int[SIZE];
for (int i=0; i<notches.length; i++)
notches[i] = r.nextInt(10);
}
// A standard constructor given the information stored in a Nut.
public Nut(int[] digits) {
notches = new int[SIZE];
for (int i=0; i<SIZE; i++)
notches[i] = digits[i];
}
// Need this to access a single digit.
public int getDigit(int i) {
return notches[i];
}
// Here we define a compareTo.
public int compareTo(Bolt n) {
int[] tmp = new int[SIZE];
int carry = 0;
boolean low = false;
// Add up the numbers stored in this and n.
for (int i=0; i<SIZE; i++) {
tmp[i] = (carry + notches[i] + n.getDigit(i))%10;
carry = (carry + notches[i] + n.getDigit(i))/10;
if (tmp[i] < 9)
low = true;
}
// Our sum is a bunch of 9s, so we've got a match!
if (tmp[SIZE-1] == 9 && !low)
return 0;
// Our sum is too big, so make this nut too big.
else if (carry > 0)
return 1;
// Opposite case.
else
return -1;
}
// Works just like the mirror method in the Bolt class.
public Bolt getMatchingBolt() {
int[] tmp = new int[SIZE];
for (int i=0; i<7; i++)
tmp[i] = 9 - notches[i];
return new Bolt(tmp);
}
// For debugging purposes.
/*public void print() {
for (int i=0; i<SIZE; i++)
System.out.print(notches[SIZE-1-i]);
}*/
}
class NutsBolts {
// Returns true iff each nut and each corresponding bolt in the two
// respective arrays match eacy other.
public static boolean correctFit(Nut[] nuts, Bolt[] bolts) {
// Try out each corresponding nut and bolt.
for (int i=0; i<nuts.length; i++)
// See if these don't match.
if (nuts[i].compareTo(bolts[i]) != 0)
return false;
// If we get here, they all matched.
return true;
}
// Creates an array of Bolt objects with size number of elements utilizing
// r.
public static Bolt[] makeRandomBolts(Random r, int size) {
// Allocate space for our bolts,
Bolt[] tmp = new Bolt[size];
// Just create each object here and return the array.
for (int i=0; i<size; i++)
tmp[i] = new Bolt(r);
return tmp;
}
// Creates an array of matching nuts to the array of bolts passed in.
// It scrambles the nuts though, so that they are no longer in the correct
// locations.
public static Nut[] makeMatchingNuts(Random r, Bolt[] bolts) {
// Create the array, and add in each matching nut.
Nut[] tmp = new Nut[bolts.length];
for (int i=0; i<bolts.length; i++) {
tmp[i] = bolts[i].getMatchingNut();
}
// Here we mix the array of nuts up.
for (int i=0; i<3*bolts.length; i++) {
// Get two random indexes.
int index1 = r.nextInt(bolts.length);
int index2 = r.nextInt(bolts.length);
// Swap them!
Nut store = tmp[index1];
tmp[index1] = tmp[index2];
tmp[index2] = store;
}
// Return our array of mixed up, but matching nuts.
return tmp;
}
}
仅处理属性 - 价值组合。在纯CSS中执行此操作的唯一方法是使用CSS hack定位支持@supports的浏览器。 （没有足够的浏览器支持::-webkit-scrollbar-thumb，因为它无论如何都有助于检查对@supports的支持。）
答案 1 :(得分：1)
您现在可以使用@supports selector()定位伪元素。这是您的用例的相关示例：
=SUMIFS(INDEX($C$3:$E$17,,MATCH(J$5,$C$2:$E$2,0)),$A$3:$A$17,$I6,$B$3:$B$17,">="&$J$1,$B$3:$B$17,"<="&$J$2)
请参阅this JSFiddle，它演示了浏览器对@supports selector(::-webkit-scrollbar-thumb) {
.scroll-container {
overflow: scroll
}
}
的支持
但不是
截至2020年12月，::-webkit-scrollbar-thumb的{{3}}约为72％。
答案 2 :(得分：0)
加上前面的答案，您可以编写伪选择器，如果浏览器不支持prop，它将跳过css声明。
例如：
li::marker{color:blue}
较旧的浏览器不会显示。
答案 3 :(得分：0)
这是我用来识别 Webkit 浏览器的。这是我能找到的最具体的伪选择器，其他引擎似乎（还）没有：
CSS.supports(`selector(input[type='time']::-webkit-calendar-picker-indicator)`)