我正在非UI线程中创建一组webview对象,并在网页加载完成后将它们添加到队列中。 UI线程最终会查询webview,如果维护的队列中有元素,则会从队列中选择webview。这个非UI线程将一直运行并在需要时填充队列。不幸的是,当UI线程呈现webview时,虽然它得到了正确的呈现,但非UI线程突然以“CalledFromWrongThreadException”的错误失败了。我不确定这种行为是否符合预期。我已创建一个示例程序来演示相同的问题。有人能帮助我识别问题吗?
public class MultiThreadTest extends Activity {
private volatile WebView mWv;
private LinearLayout mLL;
private volatile Handler nonUiThreadHandler = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mLL = (LinearLayout) findViewById(R.id.linearLayout);
Button creator = (Button) findViewById(R.id.creator);
creator.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
createThread();
}
});
Button consumer = (Button) findViewById(R.id.consumer);
consumer.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mLL.addView(mWv, new LinearLayout.LayoutParams(200, 200));
mWv.requestFocus();
}
});
}
public void createThread() {
Thread t = new Thread (new Runnable() {
@Override
public void run() {
Looper.prepare();
nonUiThreadHandler = new Handler();
Looper.loop();
}
}, "Creator thread");
t.start();
while (!t.isAlive() || nonUiThreadHandler==null) {}
nonUiThreadHandler.post(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
constructView();
}
});
}
public void constructView() {
mWv = new WebView(MultiThreadTest.this);
mWv.setWebChromeClient(new WebChromeClient());
mWv.loadUrl("http://www.yahoo.com");
mWv.setFocusable(true);
}
}
runOnUiThread()
,它与处理程序相同但没有处理程序。 - bigstones