渐变背景UIScrollView

Question

如何将渐变背景添加到UIScrollView？我有一个带有UIScrollView的viewcontroller.我想为scrollview添加渐变背景.我也有一个背景渐变图像,但它不完全适合滚动视图的内容大小.

请帮忙.谢谢

Answer 1

我之前设置UIScrollView backgroundColor为清除然后在滚动视图后面定位了一个渐变视图.然后绘制一个渐变,UIView如:

- (void)drawRect:(CGRect)rect 
{
    CGContextRef currentContext = UIGraphicsGetCurrentContext();

    CGGradientRef glossGradient;
    CGColorSpaceRef rgbColorspace;
    size_t num_locations = 2;
    CGFloat locations[2] = { 0.0, 1.0 };
    CGFloat components[8] = { 0.119, 0.164, 0.192, 1.000,  // Start color
        0.286, 0.300, 0.307, 1.000 }; // End color

    rgbColorspace = CGColorSpaceCreateDeviceRGB();
    glossGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations);

    CGRect currentBounds = self.bounds;
    CGPoint topCenter = CGPointMake(CGRectGetMidX(currentBounds), 0.0f);
    CGPoint midCenter = CGPointMake(CGRectGetMidX(currentBounds), CGRectGetMaxY(currentBounds));
    CGContextDrawLinearGradient(currentContext, glossGradient, topCenter, midCenter, 0);

    CGGradientRelease(glossGradient);
    CGColorSpaceRelease(rgbColorspace); 
}

我不知道在UIScrollViews中直接绘制渐变有什么效果drawRect.