How to change truncate characters in UILabel?

问题

When the text of a UILabel gets truncated there are 3 dots inserted by default. Is it possible to change these characters or disable them?

回答1:

why dont you code to count the length of string and makes its substring if its exceeding the view. or do anything you want It is raw but effective method

回答2:

I have written a custom truncating class that you can pop into you code where ever. Just use this method below. it will return true if truncation has taken place, and MaxWidth can be left as 0 if you just want to use the labels default frame width. Put maxWidth as something less than the frames width to shorten it within its frames bounds.

Swift 2 (with some swift 3 comments for converting)

usage:

Truncater.replaceElipsis(forLabel: label, withString: "???")
let didTruncate = Truncater.replaceElipsis(forLabel: label, withString: "1234", andMaximumWidth: 50) //maxWidth is not number of chars, but label width in CGFloat

class:

import UIKit

class Truncater {

    class func replaceElipsis(forLabel label:UILabel, withString replacement:String) -> Bool {
        return replaceElipsis(forLabel: label, withString: replacement, andMaximumWidth:0)
    }

    class func replaceElipsis(forLabel label:UILabel, withString replacement:String, andMaximumWidth width:CGFloat) -> Bool {

        if(label.text == nil){
            return false
        }

        let origSize = label.frame;
        var useWidth = width

        if(width <= 0){
            useWidth = origSize.width //use label width by default if width <= 0
        }

        label.sizeToFit()
        let labelSize = label.text!.sizeWithAttributes([NSFontAttributeName: label.font]) //.size(attributes: [NSFontAttributeName: label.font]) for swift 3

        if(labelSize.width > useWidth){

            let original = label.text!;
            let truncateWidth = useWidth;
            let font = label.font;
            let subLength = label.text!.characters.count

            var temp = label.text!.substringToIndex(label.text!.endIndex.advancedBy(-1)) //label.text!.substring(to: label.text!.index(label.text!.endIndex, offsetBy: -1)) for swift 3
            temp = temp.substringToIndex(temp.startIndex.advancedBy(getTruncatedStringPoint(subLength, original:original, truncatedWidth:truncateWidth, font:font, length:subLength)))
            temp = String.localizedStringWithFormat("%@%@", temp, replacement)

            var count = 0

            while temp.sizeWithAttributes([NSFontAttributeName: label.font]).width > useWidth {

                count+=1

                temp = label.text!.substringToIndex(label.text!.endIndex.advancedBy(-(1+count)))
                temp = temp.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet()) //remove this if you want to keep whitespace on the end
                temp = String.localizedStringWithFormat("%@%@", temp, replacement)
            }

            label.text = temp;
            label.frame = origSize;
            return true;
        }
        else {

            label.frame = origSize;
            return false
        }
    }

    class func getTruncatedStringPoint(splitPoint:Int, original:String, truncatedWidth:CGFloat, font:UIFont, length:Int) -> Int {

        let splitLeft = original.substringToIndex(original.startIndex.advancedBy(splitPoint))

        let subLength = length/2

        if(subLength <= 0){
            return splitPoint
        }

        let width = splitLeft.sizeWithAttributes([NSFontAttributeName: font]).width

        if(width > truncatedWidth) {
            return getTruncatedStringPoint(splitPoint - subLength, original: original, truncatedWidth: truncatedWidth, font: font, length: subLength)
        }
        else if (width < truncatedWidth) {
            return getTruncatedStringPoint(splitPoint + subLength, original: original, truncatedWidth: truncatedWidth, font: font, length: subLength)
        }
        else {
            return splitPoint
        }
    }
}

Objective C

+ (bool) replaceElipsesForLabel:(UILabel*) label With:(NSString*) replacement MaxWidth:(float) width 

class:

//=============================================Header=====================================================
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface CustomTruncater : NSObject

+ (bool) replaceElipsesForLabel:(UILabel*) label With:(NSString*) replacement MaxWidth:(float) width;

@end

//========================================================================================================

#import "CustomTruncater.h"

@implementation CustomTruncater

static NSString *original;
static float truncateWidth;
static UIFont *font;
static int subLength;

+ (bool) replaceElipsesForLabel:(UILabel*) label With:(NSString*) replacement MaxWidth:(float) width {

CGRect origSize = label.frame;

float useWidth = width;

if(width <= 0)
    useWidth = origSize.size.width; //use label width by default if width <= 0

[label sizeToFit];
CGSize labelSize = [label.text sizeWithFont:label.font];

if(labelSize.width > useWidth) {

    original = label.text;
    truncateWidth = useWidth;
    font = label.font;
    subLength = label.text.length;

    NSString *temp = [label.text substringToIndex:label.text.length-1];
    temp = [temp substringToIndex:[self getTruncatedStringPoint:subLength]];
    temp = [NSString stringWithFormat:@"%@%@", temp, replacement];

    int count = 0;

    while([temp sizeWithFont:label.font].width > useWidth){

        count++;

        temp = [label.text substringToIndex:(label.text.length-(1+count))];
        temp = [temp stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; //remove this if you want to keep whitespace on the end
        temp = [NSString stringWithFormat:@"%@%@", temp, replacement];
    }

    label.text = temp;
    label.frame = origSize;
    return true;
}
else {
    label.frame = origSize;
    return false;
}
}

+ (int) getTruncatedStringPoint:(int) splitPoint {

NSString *splitLeft = [original substringToIndex:splitPoint];
subLength /= 2;

if(subLength <= 0)
    return splitPoint;

if([splitLeft sizeWithFont:font].width > truncateWidth){
    return [self getTruncatedStringPoint:(splitPoint - subLength)];
}
else if ([splitLeft sizeWithFont:font].width < truncateWidth) {
    return [self getTruncatedStringPoint:(splitPoint + subLength)];
}
else {
    return splitPoint;
}
}

@end

回答3:

Look at -[UILabel setLineBreakMode:] and UILineBreakModeCharacterWrap. The default value of -[UILabel lineBreakMode] is UILineBreakModeTailTruncation, which causes the ellipsis at the end.

回答4:

As Javanator said you would have to do your own truncation. You shuld use the sizeWithFont:forWidth:lineBreakMode: message on the UIKit additions to NSString class to get the width of a string with a certain font. This will handle all types of fonts.

Link

回答5:

You can also set

[lbl setAdjustsFontSizeToFitWidth:YES];

With this there will be no need of truncating text and you can display the complete text on your label.

来源：https://stackoverflow.com/questions/4793420/how-to-change-truncate-characters-in-uilabel