清除缓存步骤与显示弹框

// 单例(一个应用程序只有一个对象)

SDImageCache *sdImageCache = [SDImageCache sharedImageCache];

NSString *str = [NSString stringWithFormat:@"缓存大小%.2fM.是否清除缓存?", [sdImageCache checkTmpSize]];

NSString *cancelStr = @"取消";

if ([sdImageCache checkTmpSize] == 0) {

str = @"您还没有缓存, 不需要清理哦!";

cancelStr = nil;

}

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:str delegate:self cancelButtonTitle:cancelStr otherButtonTitles:@"确定", nil];

// 这里执行协议方法的对象是这个视图控制器对象(协议方法是给别人用的)

alertView.delegate = self;

[alertView show];

[alertView release];

// alertView协议方法执行清除缓存的方法

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;

{

if (buttonIndex == 1) {

[[SDImageCache sharedImageCache] clearDisk];

}

}

// 计算缓存文件大小方法的实现

- (float)checkTmpSize {

float totalSize = 0;

NSDirectoryEnumerator *fileEnumerator = [[NSFileManager defaultManager] enumeratorAtPath:_diskCachePath];

for (NSString *fileName in fileEnumerator) {

NSString *filePath = [_diskCachePath stringByAppendingPathComponent:fileName];

NSDictionary *attrs = [[NSFileManager defaultManager] attributesOfItemAtPath:filePath error:nil];

unsigned long long length = [attrs fileSize];

totalSize += length / 1024.0 / 1024.0;

} // NSLog(@"tmp size is %.2f",totalSize);

return totalSize;

}