iphone开发者笔记

来源：互联网发布：mac qq 截图录屏失效编辑：程序博客网时间：2024/05/17 06:21

1.iphone之UISegmentedControl
代码：
//选择按钮
  NSArray*buttonNames = [NSArray arrayWithObjects:@"今天", @"本周", @"本月",nil];
  UISegmentedControl* segmentedControl = [[UISegmentedControl alloc]initWithItems:buttonNames];
  [segmentedControl setFrame:CGRectMake(60, 10, 200, 40)];
  segmentedControl.selectedSegmentIndex=1;
//添加事件
  [segmentedControl addTarget:self action:@selector(segmentAction:)forControlEvents:UIControlEventValueChanged];
  [self.viewaddSubview:segmentedControl];
  [segmentedControl release];
//事件
-(void)segmentAction:(UISegmentedControl *)Seg{
     NSIntegerIndex = Seg.selectedSegmentIndex;
  NSLog(@"Seg.selectedSegmentIndex:%d",Index);

}

2.键盘透明
textField.keyboardAppearance = UIKeyboardAppearanceAlert;

状态栏的网络活动风火轮是否旋转
[UIApplication sharedApplication].networkActivityIndicatorVisible，默认值是NO。

截取屏幕图片
//创建一个基于位图的图形上下文并指定大小为CGSizeMake(200,400)
UIGraphicsBeginImageContext(CGSizeMake(200,400));

//renderInContext 呈现接受者及其子范围到指定的上下文
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];

//返回一个基于当前图形上下文的图片
UIImage *aImage = UIGraphicsGetImageFromCurrentImageContext();

//移除栈顶的基于当前位图的图形上下文
UIGraphicsEndImageContext();

//以png格式返回指定图片的数据
imageData = UIImagePNGRepresentation(aImage);

更改cell选中的背景
    UIView *myview = [[UIView alloc] init];
    myview.frame = CGRectMake(0, 0, 320, 47);
    myview.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"0006.png"]];
    cell.selectedBackgroundView = myview;