我正在进行登录页面，并具有以下代码。我打开这个代码的那一刻
// Login button clicked
// ok = (Button)findViewById(R.id.btn_login);
// ok.setOnClickListener((android.view.View.OnClickListener) this);
我的应用崩溃了。我看起来大多数都使用这种方法公共类MainActivity扩展ActionBarActivity实现OnClickListener所以我跟着。在单击按钮登录以调用发布数据时启用的正确方法是什么？
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.support.v7.app.ActionBarActivity;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements OnClickListener {
Button ok,back,exit;
TextView result;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
// Login button clicked
// ok = (Button)findViewById(R.id.btn_login);
// ok.setOnClickListener((android.view.View.OnClickListener) this);
result = (TextView)findViewById(R.id.lbl_result);
}
public void postLoginData() {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
/* login.php returns true if username and password is equal to saranga */
HttpPost httppost = new HttpPost("http://www.sencide.com/blog/login.php");
try {
// Add user name and password
EditText uname = (EditText)findViewById(R.id.txt_username);
String username = uname.getText().toString();
EditText pword = (EditText)findViewById(R.id.txt_password);
String password = pword.getText().toString();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("username", username));
nameValuePairs.add(new BasicNameValuePair("password", password));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
Log.w("SENCIDE", "Execute HTTP Post Request");
HttpResponse response = httpclient.execute(httppost);
String str = inputStreamToString(response.getEntity().getContent()).toString();
Log.w("SENCIDE", str);
if(str.toString().equalsIgnoreCase("true"))
{
Log.w("SENCIDE", "TRUE");
result.setText("Login successful");
}else
{
Log.w("SENCIDE", "FALSE");
result.setText(str);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private StringBuilder inputStreamToString(InputStream is) {
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
// Read response until the end
try {
while ((line = rd.readLine()) != null) {
total.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
// Return full string
return total;
}
public void onClick(View view) {
if(view == ok){
postLoginData();
}
}
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}
以下是我尝试使用onclick事件
运行应用程序时遇到的一些错误09-30 01:58:01.075: E/AndroidRuntime(1342): FATAL EXCEPTION: main
09-30 01:58:01.075: E/AndroidRuntime(1342): Process: com.example.guard1, PID: 1342
09-30 01:58:01.075: E/AndroidRuntime(1342): android.os.NetworkOnMainThreadException
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
09-30 01:58:01.075: E/AndroidRuntime(1342): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
09-30 01:58:01.075: E/AndroidRuntime(1342): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
09-30 01:58:01.075: E/AndroidRuntime(1342): at java.net.InetAddress.getAllByName(InetAddress.java:214)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
09-30 01:58:01.075: E/AndroidRuntime(1342): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
09-30 01:58:01.075: E/AndroidRuntime(1342): at com.example.guard1.MainActivity.postLoginData(MainActivity.java:72)
09-30 01:58:01.075: E/AndroidRuntime(1342): at com.example.guard1.MainActivity.onClick(MainActivity.java:113)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.view.View.performClick(View.java:4438)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.view.View$PerformClick.run(View.java:18422)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.os.Handler.handleCallback(Handler.java:733)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.os.Handler.dispatchMessage(Handler.java:95)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.os.Looper.loop(Looper.java:136)
09-30 01:58:01.075: E/AndroidRuntime(1342): at android.app.ActivityThread.main(ActivityThread.java:5017)
09-30 01:58:01.075: E/AndroidRuntime(1342): at java.lang.reflect.Method.invokeNative(Native Method)
09-30 01:58:01.075: E/AndroidRuntime(1342): at java.lang.reflect.Method.invoke(Method.java:515)
09-30 01:58:01.075: E/AndroidRuntime(1342): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-30 01:58:01.075: E/AndroidRuntime(1342): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-30 01:58:01.075: E/AndroidRuntime(1342): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：5)
删除此导入
import android.content.DialogInterface.OnClickListener;
并添加此导入
import android.view.View.OnClickListener;
答案 1 :(得分：0)
您可以使用
ok.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
...
}
});
并添加
import android.view.View;
或只是替换
import android.content.DialogInterface.OnClickListener;
与
import android.view.View.OnClickListener;
答案 2 :(得分：0)
首先导入包
import android.view.View.OnClickListener;
而不是：
ok.setOnClickListener((android.view.View.OnClickListener) this);
试试这个：
ok.setOnClickListener(this);
如果你删除了活动的implements方法 然后你可以直接使用这个
ok.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO
}
});
而不是ok.setOnClickListener(this);
答案 3 :(得分：0)
使用OnClickListener。
ok.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
...
}});
在主线程中工作的onClick回调，这就是你遇到异常的原因。使用后台线程进行网络交互。加载器 - 它是一个很好的安卓解决方案： http://developer.android.com/guide/components/loaders.html