iOS oc 跳出for循环
时间: 2023-12-08 08:39:07 浏览: 86
以下是在iOS Objective-C中跳出for循环的两种方法:
1.使用break语句跳出循环:
```objective-c
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if (i == 2 && j == 4) {
NSLog(@"j ==== > %d",j);
break; // 跳出内层循环
}
}
NSLog(@"i ==== > %d",i);
}
```
2.使用goto语句跳出循环:
```objective-c
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if (i == 2 && j == 4) {
NSLog(@"j ==== > %d",j);
goto b; // 跳转到标签b处
}
}
NSLog(@"i ==== > %d",i);
}
b:{
int a = 10;
NSLog(@"a =====> %d",a);
}
```
相关问题
iOS OC 跳出for循环
在iOS Objective-C中,要跳出for循环可以使用`break`语句。当满足某个条件时,可以使用`break`语句来立即终止当前的循环,并跳出循环体。
以下是一个示例代码:
```objective-c
for (int i = 0; i < 10; i++) {
if (i == 5) {
break; // 当i等于5时跳出循环
}
NSLog(@"%d", i);
}
```
在上述代码中,当`i`等于5时,`break`语句会被执行,循环会立即终止,输出结果为0、1、2、3、4。
ios oc 文件选择
在iOS Objective-C中,文件选择通常涉及到用户从设备的文件系统中选择文件,这通常发生在需要访问用户相册、文档或其他本地文件的应用场景中。你可以使用`UIImagePickerController`来进行这样的操作。
首先,导入所需框架:
```objc
#import <UIKit/UIKit.h>
```
然后,在需要的视图控制器(UIViewController)中,实现`UIImagePickerControllerDelegate`协议,并设置代理:
```objc
@interface YourViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
```
接着,创建选择图片或文件的方法,比如选择照片:
```objc
- (IBAction)selectImage:(id)sender {
UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.delegate = self;
imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; // 或者UIImagePickerControllerSourceTypeSavedPhotosAlbum
[self presentViewController:imagePickerController animated:YES completion:nil];
}
```
当用户选择完成后,会触发`imagePickerController:didFinishPickingMediaWithInfo:`方法,你可以在其中获取所选文件路径或数据:
```objc
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<UIImagePickerControllerInfoKey,id> *)info {
UIImage *selectedImage = info[UIImagePickerControllerOriginalImage]; // 获取图片
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); // 获取沙盒路径
NSString *documentsDirectory = paths[0];
// 将图片保存到指定目录
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"selected_image.jpg"];
NSData *imageData = UIImagePNGRepresentation(selectedImage);
[imageData writeToFile:filePath atomically:YES];
[picker dismissViewControllerAnimated:YES completion:nil];
}
```
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