iOS UITextField的代理的几点笔记

 今天做项目的时候，有个需求，点击按钮，就在特定的编辑框输入按钮中的文字，一开始我还以c++的思想来写，先获取光标的位置，然后在判断是否在那个编辑框，进行输入。后来我旁边的同事看到了直接教我用代理方法，因为接触ios没多久，也不清楚<uitextfielddelegate>的用法。非常感谢我同事。

1、代理<uitextfielddelegate>

@interface idiom_viewcontroller ()<uitextfielddelegate>
{
    uitextfield * _selecttf;
    nsarray *uibutton_array;
}
@property (weak, nonatomic) iboutlet uitextfield *first_idiom;
@property (weak, nonatomic) iboutlet uitextfield *second_idiom;
@property (weak, nonatomic) iboutlet uitextfield *third_idiom;

- (void)viewdidload {
    [super viewdidload];
    //实现uitextfielddelegate的协议
    _first_idiom.delegate=self;
    _second_idiom.delegate =self;
    _third_idiom.delegate =self;
    //点击编辑框隐藏软键盘
    _first_idiom.inputview =[uiview new];
    _second_idiom.inputview =[uiview new];
    _third_idiom.inputview =[uiview new];
    //创建手势识别对象并监听手势
    uitapgesturerecognizer * tap =[[uitapgesturerecognizer alloc]initwithtarget:self action:@selector(tapaction)];
    [self.view addgesturerecognizer:tap];
    // do any additional setup after loading the view from its nib.
}

//失去焦点
-(void)tapaction{
    [self.view endediting:yes];
}

-(void)textfielddidendediting:(uitextfield *)textfield{
    _isbegintf =no;
}

-(void)textfielddidbeginediting:(uitextfield *)textfield
{
    _isbegintf =yes;
    _selecttf =textfield;
}

2、按钮点击事件-编辑框输入按钮文字

- (void)button_word:(uibutton *)btn
{
    if (!_isbegintf) {
        return;
    }
    _selecttf.text = [nsstring stringwithformat:@"%@%@",_selecttf.text,btn.titlelabel.text];
    btn.userinteractionenabled =no;
    btn.backgroundcolor =[uicolor lightgraycolor];
}

3、删除按钮事件

- (ibaction)gobackbuttonaction:(id)sender {
    if (!_isbegintf) {
        return;
    }
    
    if ([_selecttf.text isequaltostring:@""]) {
        return;
    }
    //获取编辑框最后一个文字
    nsstring *gabackstr =[_selecttf.text substringwithrange:nsmakerange(_selecttf.text.length-1, 1)];
    //获取编辑框length -1的文字
    _selecttf.text =[_selecttf.text substringtoindex:_selecttf.text.length -1];
    
    for (int i=0; i<12; i++) {
         uibutton *btn= uibutton_array[i];
        //判断删除的文字和按钮中的文字是否相同
        if ([btn.titlelabel.text isequaltostring:gabackstr]) {
            //相同，按钮从不可点击变为可点击，颜色改变
            btn.userinteractionenabled =yes;
            btn.backgroundcolor =[uicolor orangecolor];
            return;
        }
    }
    
}