ios添加自定义inputView

Question

I'm stuck on a concept in iOS that I can't seem to understand, no matter how much I read about it. I'm trying to override the standard iOS number pad with a custom design. When the user touches the UITextField, I want the custom inputView to reveal instead of the standard number pad.

I created an separate .h/.m/.xib ViewController class for my custom inputView called "customInputViewController" Right now, it's just a dark background and one button that obscures about half of the screen when the UITextField is touched (similar to the number pad, but it just looks different). My implementation fails when I click the one button in my custom inputView -- iOS throws an EXC_BAD_ACCESS error.

This is how I load the .xib file at runtime and attach the custom inputView to the UITextField object:

UIViewController *v = [[customInputViewController alloc] initWithNibName:@"customInputDesign" bundle:nil];
myTextInput.inputView = v.view;

In the .xib file of the custom inputView, I set the File's Owner to be "customInputViewController" and I created an (IBAction) method and attached it to a UIButton. When that button is clicked, the (IBAction) is set up to send an NSLog(@"Button Clicked") message. Nothing special. It's just a simple boilerplate implementation that continues to throw an error.

Maybe I'm doing this entirely wrong. Can anyone provide a simple example?

Answer 1

The view v.view is retained as the inputView property is defined as (readwrite, retain). However, if you release your customInputViewController v somewhere before the input button is clicked, you will get a crash (EXC_BAD_ACCESS)

You can try this in your main controller:

- (IBAction) keyboardButtonClicked
{
    NSLog(@"keyboard Button Clicked");
}

- (void) viewDidLoad
{
    // do your stuff here ...

    UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)]; // add autorelease if you don't use ARC
    v.backgroundColor = [UIColor darkGrayColor];
    UIButton *b = [UIButton buttonWithType:UIButtonTypeCustom];
    [b setTitle:@"Test button" forState:UIControlStateNormal];
    [b addTarget:self action:@selector(keyboardButtonClicked) forControlEvents:UIControlEventTouchUpInside];
    b.frame = CGRectMake(80, 25, 160, 50);
    [v addSubview:b];
    myTextInput.inputView = v;
}

Should work fine ...

Answer 2

First of all, Take a look at this

The UIKit framework includes support for custom input views and input accessory views. Your application can substitute its own input view for the system keyboard when users edit text or other forms of data in a view. For example, an application could use a custom input view to enter characters from a runic alphabet. You may also attach an input accessory view to the system keyboard or to a custom input view; this accessory view runs along the top of the main input view and can contain, for example, controls that affect the text in some way or labels that display some information about the text.

To get this feature if your application is using UITextView and UITextField objects for text editing, simply assign custom views to the inputView and inputAccessoryView properties. Those custom views are shown when the text object becomes first responder...

Actually i don't need to mention all this mess to you, but there is an interesting reason for mentioning this, from the first sentence i am mentioning view-view-view, but you are making the input view in a separate view controller and you are trying to assign it as an input view of your textfield and init shouldn't be creating the view, loadView does that. Calling the view getter (v.view) when view is nil will cause loadView to be invoked.Thats why it is crashing with EXC_BAD_ACCESS.

Source : Text, Web, and Editing Programming Guide for iOS