(ios实战)实现类似于android 的toast控件

1实现原理

 创建一个自定义控件，控件中显示文本，同时设置一个动画，三秒钟后，控件的alpha为0,动画完成后，控件移出掉ViewControl

 

2 创建PopView

2.1 PopView.h 部分

@interface PopView : UIView
{
    UILabel         *_textLabel;
    int             _queueCount;
}

- (void) setText:(NSString *) text;

@end

2.2 PopView.m

#import "PopView.h"
#import <QuartzCore/QuartzCore.h>
@implementation PopView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent: 0.75f];
        self.layer.cornerRadius = 5.0f;
        _textLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 10)];
        _textLabel.numberOfLines = 0;
        _textLabel.font = [UIFont systemFontOfSize:17];
        _textLabel.textColor = [UIColor whiteColor];
        _textLabel.textAlignment = NSTextAlignmentCenter;
        _textLabel.backgroundColor = [UIColor clearColor];
        _textLabel.textAlignment = NSTextAlignmentCenter;
        [self addSubview:_textLabel];
        _queueCount = 0;
    }
    return self;
}




- (void) setText:(NSString *) text
{
    _textLabel.frame = CGRectMake(0, 0, 100, 10);
    _queueCount ++;
    self.alpha = 1.0f;
    _textLabel.text = text;
    [_textLabel sizeToFit];
    CGRect frame = CGRectMake(5, 0, _textLabel.frame.size.width, _textLabel.frame.size.height);
    _textLabel.frame = frame;
   frame =  CGRectMake(self.frame.origin.x, self.frame.origin.y, _textLabel.frame.size.width+10, _textLabel.frame.size.height+10);
    self.frame = frame;
    [UIView animateWithDuration:3.0
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseIn
                     animations:^{
                         self.alpha = 0;
                     }
                     completion:^(BOOL finished){
                         if (_queueCount == 1) {
                             [self removeFromSuperview];
                         }
                        _queueCount--;

                     }
     ];
    
}


@end

3 调用方式：

[self.view addSubview:_popView];
    [_popView setText:@"合成恢复"];