如何在iPhone中以编程方式将图像旋转90度?

如何在iPhone中以编程方式将图像旋转90度?,iphone,objective-c,cocoa-touch,ios4,image-rotation,Iphone,Objective C,Cocoa Touch,Ios4,Image Rotation,可能重复: 如何在iPhone中以编程方式将图像旋转90度?此代码将旋转按钮 UIButton *btn=[UIButton buttonWithType:UIButtonTypeRoundedRect]; [btn setFrame:CGRectMake(100, 100, 200, 44)]; btn.transform=CGAffineTransformMakeRotation(M_PI / -4); [btn setTitle:@"RakeshBhatt" forState:UICon

可能重复:


如何在iPhone中以编程方式将图像旋转90度?

此代码将旋转按钮

UIButton *btn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setFrame:CGRectMake(100, 100, 200, 44)];
btn.transform=CGAffineTransformMakeRotation(M_PI / -4);
[btn setTitle:@"RakeshBhatt" forState:UIControlStateNormal];
[self.view addSubview:btn];
旋转图像视图的方法与此相同。

请参见:


几乎完美的答案。你给了我180度的旋转,我想要90度,但除此之外,这正是我所需要的。非常感谢。:)使用
M_PI
代替
3.14159265
,使用
M_PI
代替
M_PI/2
 myImage.center = CGPointMake(0, 0);
 myImage.transform = CGAffineTransformMakeRotation([degreesToRadians:imageRotationFix]);
//create rect
UIImageView *myImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"my_image.png"]];

//set point of rotation
myImageView.center = CGPointMake(100.0, 100.0);

//rotate rect
myImageView.transform = CGAffineTransformMakeRotation(M_PI_2); //rotation in radians