ios - UITabBarItem の画像を削除し、タイトルを縦に並べることは可能ですか?

Question

私は持ってUITabBarいますが、画像を設定したくありません タイトルを設定したいだけで、このタイトルを縦に並べたいです。これは可能ですか？

ありがとう

Answer 1

私が知っていることではありません。テキストラベルの画像を作成する必要があると思います（選択したグラフィックツールで事前に作成するか、実行時にプログラムで作成できます）。

プログラムで実行したい場合は、次のような方法で実行できます。渡されたテキストを使用して中央揃えの画像を作成し、ワードラップを実行します。

UITabBarItem *item = [self.tabBar.items objectAtIndex:0];
item.image = [self makeThumbnailFromText:@"Tab Bar One"];
item.title = nil;

item = [self.tabBar.items objectAtIndex:1];
item.image = [self makeThumbnailFromText:@"Tab Bar Two"];
item.title = nil;

これは、渡されたテキストをレンダリングしてビットマップを作成する小さなメソッドを使用します。タブ バー コントローラーの画像を最適化するには、画像サイズとフォント サイズをいじる必要がある場合があります。

- (UIImage *)makeThumbnailFromText:(NSString *)string {
    // some variables that control the size of the image we create, what font to use, etc.

    CGSize imageSize = CGSizeMake(60, 80);
    CGFloat fontSize = 13.0;
    NSString *fontName = @"Helvetica-Bold";
    UIFont *font = [UIFont fontWithName:fontName size:fontSize];
    CGFloat lineSpacing = fontSize * 1.2;

    // set up the context and the font

    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0);
    NSDictionary *attributes = @{NSFontAttributeName: font};

    // some variables we use for figuring out the words in the string and how to arrange them on lines of text

    NSArray <NSString *> *words = [string componentsSeparatedByString:@" "];
    NSMutableArray <NSDictionary *> *lines = [NSMutableArray array];
    NSString *lineThusFar;
    CGSize sizeThusFar = CGSizeZero;

    // let's figure out the lines by examining the size of the rendered text and seeing whether it fits or not and
    // figure out where we should break our lines (as well as using that to figure out how to center the text)

    for (NSString *word in words) {
        NSString *currentLine = lineThusFar ? [NSString stringWithFormat:@"%@ %@", lineThusFar, word] : word;
        CGSize size = [currentLine sizeWithAttributes: attributes];
        if (size.width > imageSize.width && lineThusFar) {
            [lines addObject:@{@"text": lineThusFar, @"size": [NSValue valueWithCGSize: sizeThusFar]}];
            lineThusFar = word;
            sizeThusFar = [word sizeWithAttributes: attributes];
        } else {
            lineThusFar = currentLine;
            sizeThusFar = size;
        }
    }
    if (lineThusFar) {
        [lines addObject:@{@"text": lineThusFar, @"size": [NSValue valueWithCGSize: sizeThusFar]}];
    }

    // now write the lines of text we figured out above

    CGFloat totalSize = (lines.count - 1) * lineSpacing + fontSize;
    CGFloat topMargin = (imageSize.height - totalSize) / 2.0;

    for (NSInteger i = 0; i < lines.count; i++) {
        CGFloat x = (imageSize.width - [lines[i][@"size"] CGSizeValue].width) / 2.0;
        CGFloat y = topMargin + i * lineSpacing;
        [lines[i][@"text"] drawAtPoint:CGPointMake(x, y) withAttributes: attributes];
    }

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

Swift では、次のようになります。

func makeThumbnailFromText(text: String) -> UIImage {
    // some variables that control the size of the image we create, what font to use, etc.

    struct LineOfText {
        var string: String
        var size: CGSize
    }

    let imageSize = CGSize(width: 60, height: 80)
    let fontSize: CGFloat = 13.0
    let fontName = "Helvetica-Bold"
    let font = UIFont(name: fontName, size: fontSize)!
    let lineSpacing = fontSize * 1.2

    // set up the context and the font

    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
    let attributes = [NSFontAttributeName: font]

    // some variables we use for figuring out the words in the string and how to arrange them on lines of text

    let words = text.componentsSeparatedByString(" ")
    var lines = [LineOfText]()
    var lineThusFar: LineOfText?

    // let's figure out the lines by examining the size of the rendered text and seeing whether it fits or not and
    // figure out where we should break our lines (as well as using that to figure out how to center the text)

    for word in words {
        let currentLine = lineThusFar?.string == nil ? word : "\(lineThusFar!.string) \(word)"
        let size = currentLine.sizeWithAttributes(attributes)
        if size.width > imageSize.width && lineThusFar != nil {
            lines.append(lineThusFar!)
            lineThusFar = LineOfText(string: word, size: word.sizeWithAttributes(attributes))
        } else {
            lineThusFar = LineOfText(string: currentLine, size: size)
        }
    }
    if lineThusFar != nil { lines.append(lineThusFar!) }

    // now write the lines of text we figured out above

    let totalSize = CGFloat(lines.count - 1) * lineSpacing + fontSize
    let topMargin = (imageSize.height - totalSize) / 2.0

    for (index, line) in lines.enumerate() {
        let x = (imageSize.width - line.size.width) / 2.0
        let y = topMargin + CGFloat(index) * lineSpacing
        line.string.drawAtPoint(CGPoint(x: x, y: y), withAttributes: attributes)
    }

    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return image
}

と

var item = tabBar.items![0]
item.image = makeThumbnailFromText("Tab Bar One")
item.title = nil;

item = tabBar.items![1]
item.image = makeThumbnailFromText("Tab Bar Two")
item.title = nil;