项目中需要使用自定义安全键盘，随机布局，键盘区域防截屏

1. 自定义键盘，通过自定义UITextField的inputView和inputAccessoryView实现

   • 首先确定键盘上所有的字符，数字、字母、符号、控制字符等；

     self.numbers = [@"0 1 2 3 4 5 6 7 8 9" componentsSeparatedByString:@" "];
     self.letters = [@"a b c d e f g h i j k l m n o p q r s backspace uppercase t u v w x y z return" componentsSeparatedByString:@" "];
     self.controls = [@"backspace uppercase return" componentsSeparatedByString:@" "];
     self.symbols = [@"~ ` ! @ # $ % ^ & * ( ) _ - + = { [ } ] | \\ : ; \" ' < , > backspace . ? / € ￡ ¥ space  return" componentsSeparatedByString:@" "];
     

   • 每个字符一个键位，点击字符设置输入框内容，点击控制字符修改键盘或者输入

     - (void)clickKey:(UIButton *)button {
         if ([self.controls containsObject:button.titleLabel.text] || button.titleLabel.text.length==0) {
             return;
         }
         NSString *inputKey = button.titleLabel.text;
         if ([button.titleLabel.text isEqualToString:@"space"]) {
             inputKey = @" ";
         }
         self.text = [NSString stringWithFormat:@"%@%@", self.text, inputKey];
         [self sendActionsForControlEvents:UIControlEventEditingChanged];//直接设置text不会触发controlevent事件，需要调用此方法
     }
     

   • 开始编辑时，对所有字符随机排序，并重新设置所有按键

     - (void)onBeginEditing {
         self.numbers = [self shuffleArray:self.numbers];
         self.letters = [self shuffleArray:self.letters];
     //    self.symbols = [self shuffleArray:self.symbols];
         [self changeKeyboardType:self.customAccessoryView.items[2] reset:YES];
     }
     

   • 点击右上角按钮，切换键盘

     //更改键盘类型
     - (void)changeKeyboardType:(UIBarButtonItem *)item reset:(BOOL)isReset {
         self.secureKeyboardType = !isReset && self.secureKeyboardType == WMYSecureKeyboardTypeCharacter ? WMYSecureKeyboardTypeSymbol : WMYSecureKeyboardTypeCharacter;
         BOOL isSymbol = self.secureKeyboardType == WMYSecureKeyboardTypeSymbol;
         NSArray *keys = isSymbol ? self.symbols : [self.numbers arrayByAddingObjectsFromArray:self.letters];
         for (int i = 0; i < self.customInputView.subviews.count; i ++) {
             NSString *key = (keys.count - 1 < i) || [keys[i] isEqualToString:@"backspace"] || [keys[i] isEqualToString:@"uppercase"] ? @"" : keys[i];
             UIButton *keyButton = self.customInputView.subviews[i];
             if (i == 30) {//回退键
                 [self setupUppercaseButton:keyButton isKey:isSymbol];
                 [keyButton setTitle:isSymbol?key:@"" forState:UIControlStateNormal|UIControlStateSelected];
             } else if (i == 36) {//空格键
                 [self setupSpaceButton:keyButton isBig:isSymbol];
             } else if (i == 37) {//隐藏按键
                 CGRect frame = keyButton.frame;
                 frame.size = isSymbol ? CGSizeMake(0, 0) : CGSizeMake(self.keyWidth, self.keyHeight);
                 keyButton.frame = frame;
             }
             [keyButton setTitle:key forState:UIControlStateNormal];
         }
         item.title = isSymbol ? @"数字/字母" : @"符号";
     }
     

2. 洗牌算法，交换第i个和之后的某一个元素

     - (NSArray *)shuffleArray:(NSArray *)items {
         NSMutableArray *newItems = [NSMutableArray arrayWithArray:items];
         for (int i = 0; i < newItems.count; i++) {
             int randomIndex = arc4random()%(newItems.count - i) + i;
             id item = newItems[randomIndex];
             //过滤控制字符，防止控制字符交换位置引起混乱
             if ([self.controls containsObject:item] || [self.controls containsObject:newItems[i]]) continue;
             newItems[randomIndex] = newItems[i];
             newItems[i] = item;
         }
         return newItems;
     }
   

3. 防截屏，通过UITextfield的安全输入实现，将需要防截屏的区域的父视图设置为下面的view，这里设置为_customInputView = [self getSecureView];

     //防截屏
     - (UIView *)getSecureView{
         UITextField *bgTextField = [[UITextField alloc] init];
         [bgTextField setSecureTextEntry:YES];
   
         UIView *bgView = bgTextField.subviews.firstObject;
         [bgView setUserInteractionEnabled:YES];
         return bgView;
     }
   

4. 遇到的问题

   • 输入之后，不会触发UITextField的controlEvents事件；每次设置输入之后，手动调用sendActionsForControlEvents方法，触发事件
   • 控制字符在字符数组中，随机排序后，导致显示混乱；通过过滤控制字符，不参与随机排序解决
   • 按照mac键盘输入所有字符，只有33个，少于字母和数字的36个；参考别的键盘，增加了€ ￡ ¥这三个符号

5. 待完善内容

   • 还有单独数字输入的键盘，由于时间不够，暂时没写
   • 点击按键放大动画，因为时间问题，还没实现

6. 参考链接

   • iOS防截屏-完全解决
   • iconfont图标
   • iOS安全键盘
   • UITextField的inputView和inputAccessoryView注意点