Question

我正在尝试用空格填充右边的字符串，以使不同的字符串长度在同一点对齐。为了做到这一点，我尝试使用以下内容。但是，我无法想象如何在％s内部使用变量namePad，就像我们使用实数一样（例如使用％（namePad）而不是％5s）

import UIKit

class NavigationController: UINavigationController {

    override func viewDidLayoutSubviews() {
        navigationBar.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 100)
    }
}

class ViewController: UIViewController {

    override var prefersStatusBarHidden: Bool {
        return true
    }
}

输出样本：

<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12118" systemVersion="16E195" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="NJV-2W-zhz">
    <device id="retina4_7" orientation="portrait">
        <adaptation id="fullscreen"/>
    </device>
    <dependencies>
        <deployment identifier="iOS"/>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12086"/>
        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
    </dependencies>
    <scenes>
        <!--Main-->
        <scene sceneID="tne-QT-ifu">
            <objects>
                <viewController id="BYZ-38-t0r" customClass="ViewController" customModule="stackoverflow_43295886" customModuleProvider="target" sceneMemberID="viewController">
                    <layoutGuides>
                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
                    </layoutGuides>
                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                    </view>
                    <navigationItem key="navigationItem" title="Main" id="CEB-N4-YPg"/>
                </viewController>
                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
            </objects>
            <point key="canvasLocation" x="897" y="791"/>
        </scene>
        <!--Navigation Controller-->
        <scene sceneID="rqG-Xx-QcO">
            <objects>
                <navigationController automaticallyAdjustsScrollViewInsets="NO" id="NJV-2W-zhz" customClass="NavigationController" customModule="stackoverflow_43295886" customModuleProvider="target" sceneMemberID="viewController">
                    <toolbarItems/>
                    <navigationBar key="navigationBar" contentMode="scaleToFill" id="klc-WP-4es">
                        <rect key="frame" x="0.0" y="0.0" width="375" height="44"/>
                        <autoresizingMask key="autoresizingMask"/>
                    </navigationBar>
                    <nil name="viewControllers"/>
                    <connections>
                        <segue destination="BYZ-38-t0r" kind="relationship" relationship="rootViewController" id="vdV-Sr-o02"/>
                    </connections>
                </navigationController>
                <placeholder placeholderIdentifier="IBFirstResponder" id="Dng-hb-kZ9" userLabel="First Responder" sceneMemberID="firstResponder"/>
            </objects>
            <point key="canvasLocation" x="133.59999999999999" y="791.15442278860576"/>
        </scene>
    </scenes>
</document>

Answer 1

您可以使用"%-"+namePad+"s"代替"%-5s"

虽然，我不确定你真的需要那个变量。您正在使用String.format，但没有给格式化变量，所以请尝试使用它。

String.format("%d - %-21s", id, name);

或者，和以前一样

int pad = 21;
return String.format("%d - %-"+pad+"s*", id, name);

例如，（添加*以显示填充）

static class Person {
    int id;
    String name;

    public Person(int id, String name) {
        this.id = id; this.name = name;
    }

    public String toString() {
        return String.format("%d - %-21s*", id, name);
    }
}

public static void main (String[] args) throws java.lang.Exception
{
    Person[] people = { 
        new Person(1, "Bill Gates"),
        new Person(2, "Trump"),
        new Person(3, "Tail"), 
        new Person(4, "James Bond")
    };

    for (Person p : people) {
        System.out.println(p);
    }
}

输出

1 - Bill Gates           *
2 - Trump                *
3 - Tail                 *
4 - James Bond           *

如何在java中的％s内使用变量而不是硬编码数字来填充pad

1 个答案: