iOS字体的放大和缩小

1.- (void)viewDidLoad先设置字体的全局变量
font=14;
2. 自定义2个按钮并添加事件
    //放大

    _zoomInBtn = [UIButton buttonWithType:UIButtonTypeCustom];

    _zoomInBtn.frame = CGRectMake(185, 7 , 30, 30);

    _zoomInBtn.backgroundColor = [UIColor clearColor];

    [_zoomInBtn setImage:[UIImage imageNamed:@"ButtonZoomIn.png"] forState:UIControlStateNormal];

    _zoomInBtn.tag = 220;

    [_zoomInBtn addTarget:self action:@selector(fontSizeAdjustment:) forControlEvents:UIControlEventTouchUpInside];

    [engLishSetView addSubview:_zoomInBtn];

    //缩小

    _zoomOutBtn = [UIButton buttonWithType:UIButtonTypeCustom];

    _zoomOutBtn.frame = CGRectMake(265, 7 , 30, 30);

    _zoomOutBtn.backgroundColor = [UIColor clearColor];

    _zoomOutBtn.tag = 221;

    [_zoomOutBtn addTarget:self action:@selector(fontSizeAdjustment:) forControlEvents:UIControlEventTouchUpInside];

    [_zoomOutBtn setImage:[UIImage imageNamed:@"ButtonZoomOut.png"] forState:UIControlStateNormal];

    [engLishSetView addSubview:_zoomOutBtn];

3.实现方法

#pragma mark - 字体调整大小事件

-(void)fontSizeAdjustment:(id)sender

{

    NSLog(@"%f",font);

    UIButton * btn = (UIButton *)sender;

    if (btn == _zoomInBtn) {

        if (font<20) {

            font = font+1;

            [_zoomOutBtn setEnabled:YES];

            [_englishDetailTable reloadData];

        }

        else

        {

            UIAlertView * alert = [[UIAlertView alloc] initWithTitle:nil message:@"字体已经为最大" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles: nil];

            [alert show];

            [_zoomInBtn setEnabled:NO];

        }

    }

    else

    {

        if (font>12) {

            font = font-1;

            [_zoomInBtn setEnabled:YES];

            [_englishDetailTable reloadData];

        }

        else

        {

            UIAlertView * alert = [[UIAlertView alloc] initWithTitle:nil message:@"字体已经为最小" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles: nil];

            [alert show];

            [_zoomOutBtn setEnabled:NO];

        }

    }

}