ios - 选择和取消选择时设置按钮图像

Question

我只是想在我的 IBAction 中设置按钮图像以切换到不同的图像:

if ([sender isSelected]) {
//1
    UIImage *unselectedImage = [[UIImage alloc]initWithContentsOfFile:@"icon_checkbox_up"];
    [sender setImage:unselectedImage forState:UIControlStateSelected];
    [sender setSelected:NO];
}
else {
//2
    UIImage *unselectedImage = [[UIImage alloc]initWithContentsOfFile:@"icon_checkbox_down"];
    [sender setImage:unselectedImage forState:UIControlStateNormal];
    [sender setSelected:YES];
}

当我点击按钮时，图像相应改变(在评论 2 下)，再次按下按钮后，图像就消失了。我不确定为什么会这样。我已经尝试了 UIControlStateSelected 和 UIControlStateNormal。我错过了什么吗？

Answer 1

如果你的文件名没有错，你可以试试这个方法。希望对您有所帮助!!

[buttn addTarget:self action:@selector(Selected) forControlEvents:UIControlEventTouchDown];
[buttn addTarget:self action:@selector(Unselected) forControlEvents:UIControlEventTouchUpInside];
[buttn addTarget:self action:@selector(Unselected) forControlEvents:UIControlEventTouchUpOutside];

-(void)Selected
{
    UIImage *unselectedImage = [[UIImage alloc]initWithContentsOfFile:@"icon_checkbox_up"];
    [buttn setImage:unselectedImage forState:UIControlStateSelected];
    [buttn setSelected:NO];
}

-(void)Unselected
{
    UIImage *unselectedImage = [[UIImage alloc]initWithContentsOfFile:@"icon_checkbox_down"];
    [buttn setImage:unselectedImage forState:UIControlStateNormal];
    [buttn setSelected:YES];
}