【发布时间】：2011-09-14 03:10:39
【问题描述】：
我有一个蓝牙脚踏开关，它基本上是一个无线键盘。一个踏板发送向上箭头键，另一个发送向下箭头键。当按下其中一个踏板时，我希望能够在我的 iPad 应用程序中执行我自己的代码。踏板的制造商告诉我应该创建一个UITextField，并在包含的UIView 中采用UIKeyInput 协议，并使用beginningOfDocument 和endOfDocument 方法来执行我的代码。我这样做了，但无论我做什么，都不会调用 UIKeyInput 或 UITextInput 方法。任何人都可以引导我完成这个，或者指导我到一个类似的教程吗？有没有更简单的方法来做到这一点？
感谢您的帮助。
这是我的 .h：
#import <UIKit/UIKit.h>
@interface Pedal_ProtocolViewController : UIViewController <UIKeyInput, UITextInput>{
UITextField *myTextField;
}
@property (nonatomic, retain) IBOutlet UITextField *myTextField;
@end
这是我的 .m：
#import "Pedal_ProtocolViewController.h"
@implementation Pedal_ProtocolViewController
@synthesize myTextField;
- (void)dealloc
{
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
[super viewDidLoad];
[myTextField canBecomeFirstResponder];
[myTextField becomeFirstResponder];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return YES;
}
#pragma mark -
#pragma mark UIKeyInput Protocol Methods
- (BOOL)hasText {
return NO;
}
- (void)insertText:(NSString *)theText {
}
- (void)deleteBackward {
}
- (BOOL)canBecomeFirstResponder {
return YES;
}
#pragma mark -
#pragma mark UITextInput Protocol Methods
- (NSString *)textInRange:(UITextRange *)range {
return @"";
}
- (void)replaceRange:(UITextRange *)range withText:(NSString *)text {
}
- (void) setSelectedTextRange: (UITextRange *) range {
}
- (UITextRange *) markedTextRange {
return nil;
}
- (NSDictionary *) markedTextStyle {
return nil;
}
- (void) setMarkedTextStyle: (NSDictionary *) style {
}
- (void)setMarkedText:(NSString *)markedText selectedRange:(NSRange)selectedRange {
}
- (void) unmarkText {
}
- (UITextPosition *) endOfDocument {
//DOWN KEY
NSLog(@"Down");
return nil;
}
- (UITextPosition *) beginningOfDocument {
//UP KEY
NSLog(@"UP");
return nil;
}
- (UITextRange *)textRangeFromPosition:(UITextPosition *)fromPosition toPosition:(UITextPosition *)toPosition{
return nil;
}
- (UITextPosition *)positionFromPosition:(UITextPosition *)position offset:(NSInteger)offset{
return nil;
}
- (UITextPosition *)positionFromPosition:(UITextPosition *)position inDirection:(UITextLayoutDirection)direction offset:(NSInteger)offset {
return nil;
}
- (NSComparisonResult) comparePosition: (UITextPosition *)position toPosition: (UITextPosition *)other {
return NSOrderedSame;
}
- (NSInteger) offsetFromPosition: (UITextPosition *)from toPosition: (UITextPosition *)toPosition {
return 0;
}
- (void) setInputDelegate: (id <UITextInputDelegate>) delegate {
}
- (id <UITextInputDelegate>) inputDelegate {
return nil;
}
- (id <UITextInputTokenizer>) tokenizer {
return nil;
}
- (UITextPosition *)positionWithinRange:(UITextRange *)range farthestInDirection:(UITextLayoutDirection)direction {
return nil;
}
- (UITextRange *) characterRangeByExtendingPosition: (UITextPosition *) position inDirection: (UITextLayoutDirection) direction {
return nil;
}
- (UITextWritingDirection) baseWritingDirectionForPosition: (UITextPosition *)position inDirection: (UITextStorageDirection)direction {
return 0;
}
- (void) setBaseWritingDirection: (UITextWritingDirection)writingDirection forRange:(UITextRange *)range {
}
- (CGRect) firstRectForRange: (UITextRange *) range {
return CGRectZero;
}
- (CGRect) caretRectForPosition: (UITextPosition *) position {
return CGRectZero;
}
- (UITextPosition *) closestPositionToPoint: (CGPoint)point {
return nil;
}
- (UITextPosition *) closestPositionToPoint: (CGPoint)point withinRange: (UITextRange *) range {
return nil;
}
- (UITextRange *) characterRangeAtPoint: (CGPoint)point {
return nil;
}
- (UITextRange *) selectedTextRange {
return [[UITextRange alloc]init];
}
@end
【问题讨论】：
-
我现在也遇到了同样的问题，你解决了吗？
-
Github 上的 DCIntrospect project 中有一些有用的花絮。这些家伙正在使用一些简洁的选择跟踪来区分上、下、左、右以及所有四个，也可以使用 shift 和 option。总而言之，我想，这是一个非常令人印象深刻的努力。
标签： objective-c ios ipad subclass