我正在尝试在同一个 WebView 上运行许多 AsyncTask 来执行 loadData()。例如,我有 3 个线程,包含 3 个内容:“一”、“二”、“三”和一个内容为“abc”的 WebView。(就像下面的代码)
完成 3 个任务后,我希望 WebView 有内容:“abcOneTwoThree”。这段代码的想法是三个线程随时将其内容附加到WebView,因此结果可能是“abcTwoOneThree”或“abcTwoThreeOne”等......
我阅读了许多并发文章,但仍然不明白如何实现这一点。这是我的代码。它只打印“abcThree”。
public class UsingSameWebViewActivity extends Activity implements OnClickListener {
private Button button1;
private WebView webView;
private String result;
@Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button1 = (Button)findViewById(R.id.button1);
button1.setOnClickListener(this);
webView = (WebView)findViewById(R.id.webView1);
result = "abc";
}
@Override
public void onClick(final View v) {
final String[] contents = {"One", "Two", "Three"};
for(int i = 0; i < 3; ++i) {
final FooTask task = new FooTask(webView, result);
task.execute(contents[i]);
}
}
private class FooTask extends AsyncTask<String, Void, String> {
private final WebView resultView;
private String result;
// This is what I try to make it work right.
private synchronized String getResult() {
return result;
}
public FooTask(final WebView resultView, final String result) {
this.resultView = resultView;
this.result = result;
}
@Override
protected String doInBackground(final String... params) {
// Do a long time work randomly then returns a string.
return params[0];
}
@Override
protected void onPostExecute(final String content) {
result = getResult() + content;
resultView.loadData(result, "text/html", "utf-8");
}
}
}