java - 将值从辅助线程传递到主线程

Question

我有一个带有 try-catch block 的线程。在 try block 内，我将 HTML 存储在一个变量中，我想将其加载到 web View 中。现在Android/Java不允许Webview在主线程之外的任何地方被调用。

如何在线程范围之外传递这个字符串变量值？将字符串变量设为 Final 并声明外部线程没有帮助。

public class MyCustomView extends LinearLayout {
//UI elements
private WebView mWebView;
final Activity activity = (Activity) this.getContext();

new Thread(new Runnable() {

        @Override
        public void run() {
            try {

                //Using thread because accessing network
                URL obj = new URL(adrequesturl);
                HttpURLConnection con = (HttpURLConnection) obj.openConnection();
                con.setRequestMethod("GET");


                if (con.getResponseCode() == 200) {

                //*****Need this variable's value in the Main Thread
                String dataToLoad="some_custom_html";


              //mWebView is a webview that I have created and below can not get executed from inside helper thread                      
              //mWebView.loadData(dataToLoad, "text/html", "utf-8");-

                } else {
                    //Some code
                }

            } catch (Exception e) {
                    //Some code
            }
        }

    }).start();


//**solution which worked for me**  
activity.runOnUiThread(new Runnable() {
                    public void run() {
                        mWebView.loadData(dataToLoad, "text/html", "utf-8");
                    }
                });


  //Now we are back to main thread

  //********Main Problem**************
  //Below mWebView.loadData is allowed but I can not get dataToLoad value here
  //mWebView.loadData(dataToLoad, "text/html", "utf-8");

}

Answer 1

您可以通过这种方式在 UI 线程中运行部分代码:

this.getContext().runOnUiThread(new Runnable() {
    public void run() {
        mWebView.loadData(dataToLoad, "text/html", "utf-8");
    }
});