iOS中自动释放问题？(2)

    //path成员变量，文件路径－自动释放对象
    path=[docstr stringByAppendingPathComponent:@"1.png"];
    //调用方法，path做参数      
    [self saveData:path];
    //分割线
-(void)saveData:(NSString *)filePath
{
    //data读取内容
    NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"IMG_1340" ofType:@"PNG"];
    NSData *data= [NSData dataWithContentsOfFile:imagePath];
    //用path去保存data
    [data writeToFile:filePath atomically:NO];
} 例子2,这么写，也没问题，文件能保存。或者[self  saveData:path]; 改成[self saveData];  saveData方法不传入参数，用成员变量path代替filePath的作用，这么写，也没问题。[html] view plaincopyprint?    //例子3 
    NSArray*patharray=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString*docstr=[patharray objectAtIndex:0];    
    //path成员变量，文件路径－自动释放对象 
    path=[docstr stringByAppendingPathComponent:@"1.png"]; 
    
    //创建按钮 
    UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(0.0, 0.0, 100, 100)]; 
    button.backgroundColor = [UIColor redColor]; 
    [button addTarget:self action:@selector(saveData) forControlEvents:UIControlEventTouchUpInside]; 
    [self.view addSubview:button]; 
-(void)saveData 
{ 
    //data读取内容 
    NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"IMG_1340" ofType:@"PNG"]; 
    NSData *data= [NSData dataWithContentsOfFile:imagePath];  
    //用path去保存data 
    [data writeToFile:path atomically:NO];  
} 

    //例子3
    NSArray*patharray=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString*docstr=[patharray objectAtIndex:0];  
    //path成员变量，文件路径－自动释放对象
    path=[docstr stringByAppendingPathComponent:@"1.png"];
  
    //创建按钮
    UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(0.0, 0.0, 100, 100)];
    button.backgroundColor = [UIColor redColor];
    [button addTarget:self action:@selector(saveData) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];