self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"清除緩存" style:(UIBarButtonItemStyleDone) target:self action:@selector(deletClink)];
- (void)deletClink {
//讀取緩存大小
NSString *str = [NSString stringWithFormat:@"%.2fM",[self readCacheSize]];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:str delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"確定", nil];
[alert show];
}
//2. 清除緩存
- (void)clearFile
{
NSString * cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES ) firstObject];
NSArray * files = [[NSFileManager defaultManager ] subpathsAtPath :cachePath];
//NSLog ( @"cachpath = %@" , cachePath);
for ( NSString * p in files) {
NSError * error = nil ;
//獲取文件全路徑
NSString * fileAbsolutePath = [cachePath stringByAppendingPathComponent :p];
if ([[NSFileManager defaultManager ] fileExistsAtPath :fileAbsolutePath]) {
[[NSFileManager defaultManager ] removeItemAtPath :fileAbsolutePath error :&error];
}
}
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
if (buttonIndex == 1) {
[self clearFile];
}
}
//1. 獲取緩存文件的大小
-( float )readCacheSize
{
NSString *cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES) firstObject];
return [ self folderSizeAtPath :cachePath];
}
//由于緩存文件存在沙箱中，我們可以通過NSFileManager API來實現對緩存文件大小的計算。
// 遍歷文件夾獲得文件夾大小，返回多少 M
- ( float ) folderSizeAtPath:( NSString *) folderPath{
NSFileManager * manager = [NSFileManager defaultManager];
if (![manager fileExistsAtPath :folderPath]) return 0 ;
NSEnumerator *childFilesEnumerator = [[manager subpathsAtPath :folderPath] objectEnumerator];
NSString * fileName;
long long folderSize = 0 ;
while ((fileName = [childFilesEnumerator nextObject]) != nil ){
//獲取文件全路徑
NSString * fileAbsolutePath = [folderPath stringByAppendingPathComponent :fileName];
folderSize += [ self fileSizeAtPath :fileAbsolutePath];
}
return folderSize/( 1024.0 * 1024.0);
}
// 計算 單個文件的大小
- ( long long ) fileSizeAtPath:( NSString *) filePath{
NSFileManager * manager = [NSFileManager defaultManager];
if ([manager fileExistsAtPath :filePath]){
return [[manager attributesOfItemAtPath :filePath error : nil] fileSize];
}
return 0;
}
