相册相机
需要遵守两个协议 UINavigationControllerDelegate,UIImagePickerControllerDelegate
@interface RootViewController ()<UINavigationControllerDelegate,UIImagePickerControllerDelegate>
@end
@implementation RootViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *cameraButton = [UIButton buttonWithType:UIButtonTypeSystem];
cameraButton.frame = CGRectMake(100,100,100,100);
cameraButton.backgroundColor = [UIColor redColor];
[cameraButton addTarget:self action:@selector(cameraAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:cameraButton];
UIButton *photoButton = [UIButton buttonWithType:UIButtonTypeSystem];
photoButton.frame = CGRectMake(100,200,100,100);
photoButton.backgroundColor = [UIColor blueColor];
[photoButton addTarget:self action:@selector(photoAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:photoButton];
}
- (void)cameraAction:(UIButton *)button{
// 判断有没有相机
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
//创建相机对象
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
//设置调用的是相机还是相册
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
//是否可以编辑
picker.allowEditing = YES;
//设置代理
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
[picker release];
}
}
- (void)photoAction:(UIButton *)button{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
[picker release];
}
}
// 实现协议中的方法
//选完照片 或者 拍摄完成后 调用的方法
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(200,100,200,200)];
imgView.image = [info objectForKey:UIImagePickerControllerOriginalImage];//info字典里的key值可以用NSLog打印出来，OriginalImage是原始图片；
[self addSubview:imgView];
[imgView release];
[self dismissViewControllerAnimated:YES completion:nil];// 这里dismiss的是弹出来的相册界面；
}
Transform
transform 本质是一个3*3的矩阵，通过改变其中的元素可以达到对UIView的缩放，平移，旋转的效果，但实际上UIView的frame却不会改变；
[a b 0
c d 0 * [x1 y1 1]
tx ty 1]
x2 = a*x1 + c*y1 + tx;
y2 = b*x1 + d*y1 + ty;
//CGAffineTranform方法对view的Transform属性的改变可以用以上两个矩阵相乘的结果来表示
struct CGAffineTransform {
CGFloat a, b, c, d;// 这四个参数是用于控制transform属性的旋转和缩放
CGFloat tx, ty; // 这两个参数是用于控制transform属性的平移
};
************************************************
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(100,100,100,100)];
[self.view addSubview:view];
[view release];
view.transform = CGAffineTransformMakeTranslation(tx, ty);//返回矩阵[1 0 0 1 tx ty];
//相乘结果是
//x2 = x1 + tx; 在X轴移动tx个单位
//y2 = y1 + ty; 在Y轴移动ty个单位
view.transform = CGAffineTransformMakeScale(sx ,sy);// 返回矩阵[sx 0 0 sy 0 0];
//相乘结果是
//x2 = x1*sx; X轴放大（缩小）为原来的sx倍
//y2 = y1*sy; Y轴放大（缩小）为原来的sy倍
view.transform = CGAffineTransformMakeRotation(angle);// 返回矩阵[cos(angle) sin(angle) -sin(angle) cos(angle) 0 0];
//相乘结果是
//x2 = x1*cos(angle)+y1*sin(angle)
//y2 = x1*-sin(angle)+y1*cos(angle)
//旋转angle度;
*******************************
除了上面三种外，还有三种是方法中没有Make的，在原有参数的前面加上一个CGAffineTransform类型的参数t，返回的是在t的基础上进行对应的变化后的矩阵
这些方法在变化完成后都需要把相关对象的对应属性置为初值，否则下一次变化开始view会恢复原状，如
pinch手势的pinch.scale要置为1
rotation手势的rotation.rotation要置为0
pan手势的[pan setTranslation:CGPointZero inView:pan.view];将现在的位置置为0点;
参考资料及详细说明
http://www.cnblogs.com/smileEvday/archive/2013/04/23/Rotate1.html
博主：一片枫叶
