ios - UIImage 返回 nil

Question

我将创建一个UIImage，但如果我调试该方法，它会返回nil。我希望有人知道我必须做什么。

我的代码:

返回零:

UIImage *image1 = imgView.image;

整个代码块:

UIImage *image1 = imgView.image;
NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"];
[UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES];

更新:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

    if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {

        toolbar.hidden = NO;

        UIImage *image1 = imgView.image;
        NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
        NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"];
        [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES];

    }

    if (picker.sourceType == UIImagePickerControllerSourceTypePhotoLibrary) {

        toolbar.hidden = NO;

        UIImage *image1 = imgView.image;
        NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
        NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"];
        [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES];
    }

    if (picker.sourceType == UIImagePickerControllerSourceTypeSavedPhotosAlbum) {

        toolbar.hidden = NO;

        UIImage *image1 = imgView.image;
        NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
        NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image1.png"];
        [UIImagePNGRepresentation(image1) writeToFile:cachedImagePath atomically:YES];
    }

    else{

        toolbar.hidden = NO;

    }

    imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"];

    [self dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

第一次将 imgView.image 设置为值是在 imagePickerController:didFinishPickingMediaWithInfo: 末尾附近。因此，第一次调用此方法时，imgView.image 将为 nil，直到最后设置为:

imgView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"];