第一次尝试登录，无论登录信息是否正确，当它应该说“用户ID/密码不正确”或“登录成功!”时，我没有得到任何回复。但在第一次尝试后的任何时候它都会打印正确的消息，为什么要这样做？
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
un = (EditText) findViewById(R.id.et_un);
pw = (EditText) findViewById(R.id.et_pw);
ok = (Button) findViewById(R.id.btn_login);
// error = (TextView) findViewById(R.id.tv_error);
textview = (TextView) findViewById(R.id.textView1);
ok.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/**
* According with the new StrictGuard policy, running long tasks
* on the Main UI thread is not possible So creating new thread
* to create and execute http operations
*/
new Thread(new Runnable() {
@Override
public void run() {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("UserID",
un.getText().toString()));
postParameters.add(new BasicNameValuePair("Password",
pw.getText().toString()));
String response = null;
try {
response = SimpleHttpClient
.executeHttpPost("website",
postParameters);
res = response.toString();
resp = res.replaceAll("\\s+", "");
System.out.println(res);
} catch (Exception e) {
e.printStackTrace();
errorMsg = e.getMessage();
}
}
}).start();
try {
Thread.sleep(1000);
/**
* Inside the new thread we cannot update the main thread So
* updating the main thread outside the new thread
*/
//error.setText(resp);
if(res.indexOf("<TITLE>LoginOk</TITLE>") != -1 ||(resp.indexOf("<TITLE>Login</TITLE>") != -1)) {
textview.setText("Incorrect User ID / Password");
}
else if(res.indexOf("Already") != -1){
textview.setText("An account is already logged In");
}
else{
textview.setText("Login Successful! ");
}
if (null != errorMsg && !errorMsg.isEmpty()) {
textview.setText(errorMsg);
}
} catch (Exception e) {
textview.setText(e.getMessage());
}
}
});
}
最佳答案
在您的代码中，您放置的用于显示消息的条件在线程运行之前执行，因此您的响应始终为空或空白，这不满足您的任何条件，因此无法正确执行。
您需要做的是，在主代码实现之后，简单地实现您需要在线程中调用的处理程序。
final Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
/**
* Inside the new thread we cannot update the main thread So
* updating the main thread outside the new thread
*/
//error.setText(resp);
if(res.indexOf("<TITLE>LoginOk</TITLE>") != -1 ||(resp.indexOf("<TITLE>Login</TITLE>") != -1)) {
textview.setText("Incorrect User ID / Password");
}
else if(res.indexOf("Already") != -1){
textview.setText("An account is already logged In");
}
else{
textview.setText("Login Successful! ");
}
if (null != errorMsg && !errorMsg.isEmpty()) {
textview.setText(errorMsg);
}
}
};
Thread thread = new Thread(){
@Override
public void run() {
super.run();
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("UserID",
un.getText().toString()));
postParameters.add(new BasicNameValuePair("Password",
pw.getText().toString()));
String response = null;
try {
response = SimpleHttpClient
.executeHttpPost("http://www.e-learning.com/wlc_loginok.asp",
postParameters);
res = response.toString();
resp = res.replaceAll("\\s+", "");
System.out.println(res);
} catch (Exception e) {
e.printStackTrace();
errorMsg = e.getMessage();
}finally{
handler.sendEmptyMessage(0);
}
}
};
thread.start();
关于java - 我的第一次登录尝试没有给我任何消息，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24255679/