Iphone 以编程方式创建UIButton的新行

目前我正在水平创建一行UIButton（0,1,2,3）

int x=0;

for (int i=0; i<4; i++) {

    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    btn.frame = CGRectMake(10+x,20, 100, 100);
    x=x+120;

    [btn.titleLabel setFont:[UIFont fontWithName:@"Helvetica-Bold" size:17.0]];
    btn.tag=i;
    NSString *str=[NSString stringWithFormat:@"%d",btn.tag];
    [btn setTitle:str forState:UIControlStateNormal];

    [btn setBackgroundColor:[UIColor redColor]];

    [self.view addSubview:btn];


}

intx=0；
对于（int i=0；i
使用如下
int x=0；
int y=20；
对于（int i=0；i
use like below

int x=0;
int y = 20;
for (int i=0; i<20; i++) //20 = total button
{
     UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
     btn.frame = CGRectMake(10+x,y, 100, 100);
     x=x+120;
     [self.view addSubview:btn];
    if((i+1)%4==0)//4 means how many buttons you need for a row
    {
        y+=110;
        x=0;
    }
 }