UIImagePicker用法小结
#import "RootViewController.h"
//此frameWork中预置了一些跟系统资源相关的常量
#import <MobileCoreServices/MobileCoreServices.h>
@interface RootViewController ()
@end
@implementation RootViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSArray *array = [NSArray arrayWithObjects:@"相机",@"相册库", nil];
for (int i=0; i<array.count; i++) {
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setTitle:array[i] forState:UIControlStateNormal];
[btn addTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
btn.tag = i+100;
[btn setFrame:CGRectMake(10,74+i*40,300,50)];
[self.view addSubview:btn];
}
// Do any additional setup after loading the view.
}
//让UIImagePickerController根据不同的type加载不同的资源
//UIImagePickerController 中封装了相机、相册库等系统资源
- (void)loadSourceWithType:(UIImagePickerControllerSourceType)sourceType{
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = sourceType;
//1 设置代理@property (nonatomic, assign) id<UINavigationControllerDelegate, UIImagePickerControllerDelegate> delegate。要实现两个协议。
picker.delegate = self;
//是否对相册资源进行自动处理
picker.allowsEditing = YES;
//在程序中，对于picker习惯于通过模态化的方式呈现出来
[self presentViewController:picker animated:YES completion:^{
}];
}
//根据不同的提示信息，创建警告框
- (void)showAlertWithMessage:(NSString *)message{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"温馨提示" message:message delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alert show];
}
- (void)btnClicked:(UIButton *)btn{
switch (btn.tag) {
case 100:
{
//1 先判断资源是否可用
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
[self loadSourceWithType:UIImagePickerControllerSourceTypeCamera];
}else{
[self showAlertWithMessage:@"相机不可用"];
}
}break;
case 101:
{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
[self loadSourceWithType:UIImagePickerControllerSourceTypePhotoLibrary];
}else{
[self showAlertWithMessage:@"无法调用相册库"];
}
}break;
default:
break;
}
}
#pragma mark - picker delegate
//点击cancel按钮时，触发此方法
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
NSLog(@"cancel!");
[picker dismissViewControllerAnimated:YES completion:^{
}];
}
//选中图片资源时(choose)，会触发此方法
//info 中带有选中资源的信息
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
//先判断资源是否为图片资源(可能是video)
//获取选中资源的类型
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
//kUTTypeImage 系统预置的图片类型的常量
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
//取到图片
UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
self.view.backgroundColor = [UIColor colorWithPatternImage:image];
}
[picker dismissViewControllerAnimated:YES completion:^{
}];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end