iOS UITableView：使用 CAGradientLayer 将背景颜色指定为渐变
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/10225132/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
iOS UITableView: assign background color as gradient using CAGradientLayer
提问by vikmalhotra
I just started playing with the Master-Detail view template in Xcode 4.3 and I am trying to change the background color of master and set it to a color gradient. Here is what I tried:
我刚开始在 Xcode 4.3 中使用 Master-Detail 视图模板，我正在尝试更改 master 的背景颜色并将其设置为颜色渐变。这是我尝试过的：
Colors.m
颜色.m
#import "Colors.h"
@implementation Colors
+ (UIColor *) navigationMenuGradientTop
{
return [UIColor colorWithRed:213.0f/255.0f green:91.0f/255.0f blue:92.0f/255.0f alpha:1.0f];
}
+ (UIColor *) navigationMenuGradientBottom
{
return [UIColor colorWithRed:188.0f/255.0f green:0.0f/255.0f blue:1.0f/255.0f alpha:1.0f];
}
+ (CAGradientLayer *) navigationMenuGradient
{
NSArray *colors = [NSArray arrayWithObjects:(id)self.navigationMenuGradientTop, self.navigationMenuGradientBottom, nil];
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.colors = colors;
return gradientLayer;
}
@end
MasterViewController.m
主视图控制器.m
import "Colors.h"
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
CAGradientLayer *bgLayer = [Colors navigationMenuGradient];
bgLayer.frame = tableView.bounds;
[tableView.layer insertSublayer:bgLayer atIndex:0];
return cell;
}
Upon running I get the following error in main- Thread 1: EXC_BAD_ACCESS (code=1, address=0xxxxxxxx)
运行后，我收到以下错误main-Thread 1: EXC_BAD_ACCESS (code=1, address=0xxxxxxxx)
int main(int argc, char *argv[])
{
@autorelasespool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
I have added the QuartzCore framework to the project as well. What am I missing over here? and what direction should I generally go in when such errors occur (because the build succeeded, app seems to have crashed here)?
我也在项目中添加了 QuartzCore 框架。我在这里错过了什么？发生此类错误时，我通常应该往哪个方向走（因为构建成功，应用程序似乎在这里崩溃了）？
回答by Ankit Gupta
UIView *view = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)] autorelease];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = view.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[view.layer insertSublayer:gradient atIndex:0];
from: Gradients on UIView and UILabels On iPhone
来自：iPhone 上 UIView 和 UILabels 上的渐变
this code can help your problem.
此代码可以帮助您解决问题。
回答by Jaminyah
In order to add a background gradient to a view I followed the tutorial at this link:
为了向视图添加背景渐变，我按照此链接中的教程进行操作：
http://danielbeard.wordpress.com/2012/02/25/gradient-background-for-uiview-in-ios/
http://danielbeard.wordpress.com/2012/02/25/gradient-background-for-uiview-in-ios/
In my case I had a UITableView and wanted the gradient to be in the background. When I used the code below from the link my tableview disappeared.
就我而言，我有一个 UITableView 并希望渐变位于背景中。当我使用以下链接中的代码时，我的 tableview 消失了。
-(void) ViewWillAppear:(BOOL) animated {
CAGradientLayer *bgLayer = [BackgroundLayer blueGradient];
bgLayer.frame = self.view.bounds;
[self.view.layer insertSublayer:bgLayer atIndex:0];
}
On modifying my code as below, it was possible to have a background gradient and a tableview at the same time.
在如下修改我的代码时，可以同时拥有背景渐变和表格视图。
-(void) ViewDidAppear:(BOOL) animated {
CAGradientLayer *bgLayer = [BackgroundLayer blueGradient];
bgLayer.frame = self.view.bounds;
[self.tableView.layer insertSublayer:bgLayer atIndex:0];
}
回答by Nishant
hey check out this guy's blog here. This helped me quite a lot! I modified the class as per my requirements and VOILA!
嘿，在这里查看这个人的博客。这对我帮助很大！我根据我的要求修改了课程，瞧！
http://danielbeard.wordpress.com/2012/02/25/gradient-background-for-uiview-in-ios/
http://danielbeard.wordpress.com/2012/02/25/gradient-background-for-uiview-in-ios/
