iOS開發教程：創建透明的UIToolbar

今天需要創建一個透明的UIToolbar，便看了下SDK，使用下面代碼

1. CGRect barFrame = CGRectMake(900, 0, 124, 40);
2. UIToolbar *tb;
3. tb = [[UIToolbar alloc]initWithFrame:barFrame];
4. tb.barStyle =UIBarStyleDefault;
5. tb.tintColor = [UIColor clearColor];
6. tb.translucent = YES;

在邊緣的位置們依然能看出視圖層之間的層疊，所以查看了些資料，原來正確的方法是子類化UIToolbar，設置其backgroundColor

1. @interface TranslucentToolbar : UIToolbar
3. @end

1. @implementation TranslucentToolbar
3. - (void)drawRect:(CGRect)rect {
4. // do nothing
5. }
7. - (id)initWithFrame:(CGRect)aRect {
8. if ((self = [super initWithFrame:aRect])) {
9. self.opaque = NO;
10. self.backgroundColor = [UIColor clearColor];
11. self.clearsContextBeforeDrawing = YES;
12. }
13. return self;
14. }
15. @end

1. TranslucentToolbar *tb;
2. tb = [[TranslucentToolbar alloc]initWithFrame:barFrame];