Question

目前我有一些与此相关的内容

public class SomeActivity extends AppCompatActivity
{
    public AppCompatImageView myFavPicture;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_some);

        myFavPicture = (AppCompatImageView) findViewById(R.id.my_fav_picture);
    }

    public void setPictureToRed()
    {
        myFavPicture.setImageResource(R.color.red);
    }

    public void setPictureToLink(Uri link)
    {
        Picasso.with(this).load(link).into(myFavPicture);
    }
}

我目前遇到的问题是担心setPictureToRed和setPictureToLink

之间的竞争状况

如果我打电话给setPictureToLink(someLink)，然后在毕加索完全加载图片之前立即拨打setPictureToRed - 我担心毕加索会稍后回来并覆盖红色图片（这不是我想要的）

有没有办法做这样的事情？

public void setPictureToRed()
{
    // flush all previous loads for "myFavPicture" to avoid race conditions
    Picasso.with(this).flush(myFavPicture);
    myFavPicture.setImageResource(R.color.red);
}

Answer 1

user@dev:~/dev/kernel-sandbox$ make
sudo make -C /lib/modules/4.10.0-35-generic/build M=/home/user/dev/kernel-sandbox modules
make: Entering directory '/usr/src/linux-headers-4.10.0-35-generic'
  CC [M]  /home/user/dev/kernel-sandbox/lkm.o
In file included from ./arch/x86/include/asm/preempt.h:6:0,
                 from ./include/linux/preempt.h:59,
                 from ./include/linux/spinlock.h:50,
                 from ./include/linux/seqlock.h:35,
                 from ./include/linux/time.h:5,
                 from ./include/linux/stat.h:18,
                 from ./include/linux/module.h:10,
                 from /home/user/dev/kernel-sandbox/lkm.c:3:
/home/user/dev/kernel-sandbox/lkm.c: In function ‘hello_init’:
./include/linux/thread_info.h:21:54: error: ‘current’ undeclared (first use in this function)
 #define current_thread_info() ((struct thread_info *)current)
                                                      ^
./include/asm-generic/current.h:6:24: note: in expansion of macro ‘current_thread_info’
 #define get_current() (current_thread_info()->task)
                        ^
./include/asm-generic/current.h:7:17: note: in expansion of macro ‘get_current’
 #define current get_current()
                 ^
/home/user/dev/kernel-sandbox/lkm.c:13:17: note: in expansion of macro ‘current’
                 current->comm, current->pid);
                 ^
./include/linux/thread_info.h:21:54: note: each undeclared identifier is reported only once for each function it appears in
 #define current_thread_info() ((struct thread_info *)current)
                                                      ^
./include/asm-generic/current.h:6:24: note: in expansion of macro ‘current_thread_info’
 #define get_current() (current_thread_info()->task)
                        ^
./include/asm-generic/current.h:7:17: note: in expansion of macro ‘get_current’
 #define current get_current()
                 ^
/home/user/dev/kernel-sandbox/lkm.c:13:17: note: in expansion of macro ‘current’
                 current->comm, current->pid);
                 ^
scripts/Makefile.build:301: recipe for target '/home/user/dev/kernel-sandbox/lkm.o' failed
make[1]: *** [/home/user/dev/kernel-sandbox/lkm.o] Error 1
Makefile:1524: recipe for target '_module_/home/user/dev/kernel-sandbox' failed
make: *** [_module_/home/user/dev/kernel-sandbox] Error 2
make: Leaving directory '/usr/src/linux-headers-4.10.0-35-generic'
Makefile:3: recipe for target 'all' failed
make: *** [all] Error 2

如何取消对特定视图的毕加索请求？

1 个答案: