在專案的開發中經常需要用到一些提示框，提示使用者是否確定進行某項操作。雖然系統提供了一個UIAlter的控制元件供開發人員使用，但是系統自帶往往有侷限性，不能滿足需求了，很多時候需要自定義提示框。我寫了一個比較簡單的自定義提示框，當然可以根據自己實際的需求，在我寫的基礎上面進行自定義，去新增一些更加豐富的功能。

1、新建一個類，命名為:PopAlterView，繼承於UIView，然後新增如下程式碼：

#import <UIKit/UIKit.h>

@interface PopAlterView : UIView

@property (strong, nonatomic) UIView
 
 *transparentView;
@property (strong, nonatomic) UIView *alterView;
@property (strong, nonatomic) UILabel *labTitle;
@property (strong, nonatomic) UIButton *btnCancle;
@property (strong, nonatomic) UIButton *btnConfirm;

/**
 * 自定義提示框
 *
 *  @param theView 提示框彈出的view
 *  @param title   提示框的標題
 */
- (void
 
)showInView:(UIView *)theView withTitle:(NSString *)title;


//點選按鈕後的回撥方法
@property (nonatomic,strong) void (^btnAction)(NSInteger tag);

@end

#import "PopAlterView.h"

@implementation PopAlterView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

        _transparentView = [[UIView
 
 alloc] initWithFrame:frame];
        _transparentView.backgroundColor= [UIColor colorWithWhite:0 alpha:0.25];
        [self addSubview:_transparentView];

        _alterView = [[UIView alloc] initWithFrame:CGRectMake((frame.size.width-200)/2, (frame.size.height-100)/2, 200, 100)];
        _alterView.backgroundColor = [UIColor whiteColor];
        _alterView.layer.cornerRadius = 5.0;
        _alterView.layer.masksToBounds = YES;
        [_transparentView addSubview:_alterView];

        _labTitle = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 180, 50)];
        _labTitle.textAlignment = NSTextAlignmentCenter;
        _labTitle.numberOfLines = 0;
        [_alterView addSubview:_labTitle];

        _btnCancle = [[UIButton alloc] initWithFrame:CGRectMake(10, 60, 80, 25)];
        [_btnCancle setTitle:@"取消" forState:UIControlStateNormal];
        _btnCancle.layer.cornerRadius = 12.0;
        _btnCancle.layer.masksToBounds = YES;
        _btnCancle.backgroundColor = [UIColor grayColor];
        [_btnCancle setTag:100];
        [_btnCancle addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
        [_alterView addSubview:_btnCancle];

        _btnConfirm = [[UIButton alloc] initWithFrame:CGRectMake (105, 60, 80, 25)];
        [_btnConfirm setTitle:@"確定" forState:UIControlStateNormal];
        _btnConfirm.layer.cornerRadius = 12.0;
        _btnConfirm.layer.masksToBounds = YES;
        _btnConfirm.backgroundColor = [UIColor blueColor];
        [_btnConfirm addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
        [_btnConfirm setTag:200];
        [_alterView addSubview:_btnConfirm];
    }
    return self;
}

- (void)showInView:(UIView *)theView withTitle:(NSString *)title
{
    [theView addSubview:self];
    _labTitle.text = title;
}

-(void)btnClick:(id)sender
{
    UIButton *btn = (UIButton *)sender;
    _btnAction(btn.tag);

    [self removeFromSuperview];
}

@end

自定義提示框的類就寫好了，然後就可以呼叫了。

2、在需要呼叫的地方，進行呼叫

- (void)btnClick:(id)sender
{
    PopAlterView *alterView = [[PopAlterView alloc] initWithFrame:self.view.frame];
    [alterView showInView:self.view withTitle:@"測試"];

    alterView.btnAction = ^(NSInteger tag){
        NSLog(@"%ld",(long)tag);
    };
}

對於點選提示框上的“取消”和“確定”按鈕需要進行的操作，可以在btnAction這個回撥方法中進行。