使用按钮触发器将didFinishLaunchingWithOptions：方法移动到viewcontroller方法 [英] move didFinishLaunchingWithOptions: method to viewcontroller method with button trigger

问题描述

我在AppDelegate.h / .m中使用以下代码，但无法通过触发它的按钮将其更改为在ViewController中工作。

I had the following code working in AppDelegate.h/.m but cannot change it to work in ViewController with a button triggering it.

@implementation BSViewController

@synthesize imageView;
@synthesize workingImage;
- (IBAction) chooseImage:(id) sender {

    UIImage* testCard = [UIImage imageNamed:@"ipad 7D.JPG"];
    CGImageRef num = CGImageCreateWithImageInRect([testCard CGImage],CGRectMake(532, 0, 104, 104));
    UIGraphicsBeginImageContext(CGSizeMake( 250,650));
    CGContextRef con = UIGraphicsGetCurrentContext();
    UIImage* im = UIGraphicsGetImageFromCurrentImageContext();
    CGContextDrawImage(con, CGRectMake(0, 0, 13, 13) ,num);
    UIGraphicsEndImageContext();
    CGImageRelease(num);

    UIImageView* iv = [[UIImageView alloc] initWithImage:im];
    [self.imageView addSubview: iv];
    iv.center = self.imageView.center;
    [iv release];

我在模拟器中看到名为 Choose image的按钮，但在那里看不到图像。

I see the button named "Choose image" in the simulator, but I do not see the image there.

推荐答案

您尚未向任何视图添加 self.imageView 。
您需要

You haven't added self.imageView to any views. You need

[self.view addSubview:self.imageView];

显示您的imageView。

To show your imageView.

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