Java Can'；t在未调用循环器的线程内创建处理程序

我得到以下错误：

08-27 17:49:17.995: E/AndroidRuntime(10085): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
08-27 17:49:17.995: E/AndroidRuntime(10085):    at android.os.Handler.<init>(Handler.java:121)
08-27 17:49:17.995: E/AndroidRuntime(10085):    at android.widget.Toast$TN.<init>(Toast.java:361)
08-27 17:49:17.995: E/AndroidRuntime(10085):    at android.widget.Toast.<init>(Toast.java:97)
08-27 17:49:17.995: E/AndroidRuntime(10085):    at android.widget.Toast.makeText(Toast.java:254)

---

我如何解决这个问题？

类似的方法应该可以：

public static void alertUser(String str) {

runOnUiThread(setErrorMessage); 

}


private Runnable setErrorMessage = new Runnable() {
    @Override
    public void run() {

        Toast toast = Toast.makeText(mInstance.getApplicationContext(), str,
        Toast.LENGTH_LONG);
toast.show();
    }
};

---

似乎您正在从线程更新ui，但在这个答案上，他们提出了其他建议：

public static void alertUser(String str) {

runOnUiThread(setErrorMessage); 

}


private Runnable setErrorMessage = new Runnable() {
    @Override
    public void run() {

        Toast toast = Toast.makeText(mInstance.getApplicationContext(), str,
        Toast.LENGTH_LONG);
toast.show();
    }
};