objective-c - 更改单元格内的 UIButton 图像

Question

我很难更改包含在表格 View 单元格中的 UIButton 的图像。我的代码如下:

 // In tableview for cell at rowIndex method
 self.iconBtn = [[UIButton alloc]initWithFrame:CGRectMake(670,10,80, 80)];
            self.iconBtn.tag = kIconValueTag;

 [cell.contentView addSubview:self.iconBtn];

 //Add icon to cell
 UIImage *btnImage = [UIImage imageNamed:@"blank_star.png"];

 [self.iconBtn setImage:btnImage forState:UIControlStateNormal];

 // I am calling method changeIconState after user clicks on icon.
 [self.iconBtn addTarget:self action:@selector(changeIconState) forControlEvents:UIControlEventTouchUpInside];

按下按钮后，调用table view方法之外的一个方法:

-(void)changeIconState
{
    if (self.iconSelectState == kIconNotSelected) 
    {
        self.iconSelectState = kIconSelected;
    }
    else
    {
        self.iconSelectState = kIconNotSelected;
    }
    [self changeIcon];

}
-(void)changeIcon
{
    if (self.iconSelectState == kIconSelected) 
    {
        UIImage *btnImageHighlighted = [UIImage imageNamed:@"star.png"];
        [self.iconBtn setImage:btnImageHighlighted forState:UIControlStateNormal];
    }
    else
    {
        UIImage *btnImageNormal = [UIImage imageNamed:@"blank_star.png"];
        [self.iconBtn setImage:btnImageNormal forState:UIControlStateNormal];
    }

}

在我运行程序后，图标并没有像我想要的那样从空白变成星号。它只是一颗空白的星星。我在这里遗漏了什么吗？

Answer 1

为什么要自己管理图像/按钮状态？为什么不为定义的状态加载两个图像并让操作系统处理呢？

 //Add icon to cell
 UIImage *btnImage = [UIImage imageNamed:@"blank_star.png"];
 UIImage *btnImageHighlighted = [UIImage imageNamed:@"star.png"];

 [self.iconBtn setImage:btnImage forState:UIControlStateNormal];
 [self.iconBtn setImage:btnImageHighlighted forState:(UIControlStateHighlighted && UIControlStateSelected)];

如果您需要管理您的属性 (iconSelectedState)，您可以不用担心图像。或者，您可以查询按钮状态属性以确定它所处的状态。