有几种使用 of 的技术runOnUiThread()
,让我们看看所有
这是我的名为AndroidBasicThreadActivity的主线程(UI 线程),我将以各种方式从工作线程更新它 -
public class AndroidBasicThreadActivity extends AppCompatActivity
{
public static TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_android_basic_thread);
textView = (TextView) findViewById(R.id.textview);
MyAndroidThread myTask = new MyAndroidThread(AndroidBasicThreadActivity.this);
Thread t1 = new Thread(myTask, "Bajrang");
t1.start();
}
}
1.) 通过将 Activity 的实例作为参数传递给工作线程
class MyAndroidThread implements Runnable
{
Activity activity;
public MyAndroidThread(Activity activity)
{
this.activity = activity;
}
@Override
public void run()
{
//perform heavy task here and finally update the UI with result this way -
activity.runOnUiThread(new Runnable()
{
@Override
public void run()
{
AndroidBasicThreadActivity.textView.setText("Hello!! Android Team :-) From child thread.");
}
});
}
}
2.) 在工作线程中使用 View 的 post(Runnable runnable) 方法
class MyAndroidThread implements Runnable
{
Activity activity;
public MyAndroidThread(Activity activity)
{
this.activity = activity;
}
@Override
public void run()
{
//perform heavy task here and finally update the UI with result this way -
AndroidBasicThreadActivity.textView.post(new Runnable()
{
@Override
public void run()
{
AndroidBasicThreadActivity.textView.setText("Hello!! Android Team :-) From child thread.");
}
});
}
}
3.) 通过使用 android.os 包中
的 Handler 类 如果我们没有上下文 ( this
/ getApplicationContext()
) 或 Activity 的实例 ( AndroidBasicThreadActivity.this
),那么我们必须使用 Handler 类,如下所示 -
class MyAndroidThread implements Runnable
{
Activity activity;
public MyAndroidThread(Activity activity)
{
this.activity = activity;
}
@Override
public void run()
{
//perform heavy task here and finally update the UI with result this way -
new Handler(Looper.getMainLooper()).post(new Runnable() {
public void run() {
AndroidBasicThreadActivity.textView.setText("Hello!! Android Team :-) From child thread.");
}
});
}
}