我是Android开发中的新手。 我开发了一个包含登录的应用程序，必须在文本字段中传递凭据，然后它将调用web服务。 我面临的问题是用户和密码没有被复制到所需的位置。 请帮帮我。
package com.authorwjf.http_get;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class Main extends Activity implements OnClickListener {
EditText txtUserName;
EditText txtPassword;
@Override
public void onCreate(Bundle savedInstanceState) {
txtUserName=(EditText)this.findViewById(R.id.editText1);
txtPassword=(EditText)this.findViewById(R.id.editText2);
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.my_button).setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
Button b = (Button)findViewById(R.id.my_button);
b.setClickable(false);
new LongRunningGetIO().execute();
}
private class LongRunningGetIO extends AsyncTask <Void, Void, String> {
protected String getASCIIContentFromEntity(HttpEntity entity) throws IllegalStateException, IOException {
InputStream in = entity.getContent();
StringBuffer out = new StringBuffer();
int n = 1;
while (n>0) {
byte[] b = new byte[4096];
n = in.read(b);
if (n>0) out.append(new String(b, 0, n));
}
return out.toString();
}
@Override
protected String doInBackground(Void... params) {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
String user= txtUserName.getText().toString();
String pass= txtPassword.getText().toString();
System.out.println("USERRRR"+user);
System.out.println(pass);
//String user="at@ril.com";
//String pass= "123456";
String accessTokenQry = "{"+
"\"uid\":\""+user+"\","+
"\"password\":\""+pass+"\","+
"\"consumptionDeviceId\":\"fder-et3w-3adw2-2erf\","+
"\"consumptionDeviceName\":\"Samsung Tab\""+
"}";
HttpPost httpPost = new HttpPost("http://devssg01.ril.com:8080/v2/dip/auth/login");
httpPost.setHeader("Content-Type",
"application/json");
httpPost.setHeader("X-API-Key",
"l7xx7914b8704b2d4b029ab9c4b1b9c66dbf");
StringEntity input;
try {
input = new StringEntity(accessTokenQry);
httpPost.setEntity(input);
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String text = null;
try {
HttpResponse response = httpClient.execute(httpPost, localContext);
HttpEntity entity = response.getEntity();
text = getASCIIContentFromEntity(entity);
} catch (Exception e) {
return e.getLocalizedMessage();
}
return text;
}
protected void onPostExecute(String results) {
if (results!=null) {
EditText et = (EditText)findViewById(R.id.my_edit);
et.setText(results);
}
Button b = (Button)findViewById(R.id.my_button);
b.setClickable(true);
}
}
}
LogCat输出为：
08-10 01:20:23.977: W/dalvikvm(760): threadid=14: thread exiting with uncaught exception (group=0x414c4700)
08-10 01:20:23.984: E/AndroidRuntime(760): FATAL EXCEPTION: AsyncTask #4
08-10 01:20:23.984: E/AndroidRuntime(760): java.lang.RuntimeException: An error occured while executing doInBackground()
08-10 01:20:23.984: E/AndroidRuntime(760): at android.os.AsyncTask$3.done(AsyncTask.java:299)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.FutureTask.run(FutureTask.java:239)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.lang.Thread.run(Thread.java:841)
08-10 01:20:23.984: E/AndroidRuntime(760): Caused by: java.lang.NullPointerException
08-10 01:20:23.984: E/AndroidRuntime(760): at com.authorwjf.http_get.Main$LongRunningGetIO.doInBackground(Main.java:66)
08-10 01:20:23.984: E/AndroidRuntime(760): at com.authorwjf.http_get.Main$LongRunningGetIO.doInBackground(Main.java:1)
08-10 01:20:23.984: E/AndroidRuntime(760): at android.os.AsyncTask$2.call(AsyncTask.java:287)
08-10 01:20:23.984: E/AndroidRuntime(760): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
08-10 01:20:23.984: E/AndroidRuntime(760): ... 3 more
答案 0 :(得分：1)
您正尝试在加载布局之前初始化EditText。
如果要在布局上获取EditText，则必须在加载布局后初始化它。
这是正确的代码：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.my_button).setOnClickListener(this);
txtUserName=(EditText)this.findViewById(R.id.editText1);
txtPassword=(EditText)this.findViewById(R.id.editText2);
}
答案 1 :(得分：1)
使用此
EditText textw3d =(EditText) findViewById(R.id.editText3d);
final String strd3d = textw3d.getText().toString();
答案 2 :(得分：1)
我建议您在代码中进行更改。
只需写下以下行
super.onCreate（savedInstanceState）; 的setContentView（R.layout.main）;
上面
txtUserName =（EditText上）this.findViewById（R.id.editText1）; txtPassword =（EditText上）this.findViewById（R.id.editText2）;
答案 3 :(得分：1)
在setContentView函数调用之后移动您获取文本视图引用的行：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.my_button).setOnClickListener(this);
txtUserName=(EditText)this.findViewById(R.id.editText1);
txtPassword=(EditText)this.findViewById(R.id.editText2);
}
事实上，您需要在初始化布局中的任何窗口小部件之前调用setContentView，因为这是将layout_main.xml文件中定义的布局“加载”到您的活动中的调用。
答案 4 :(得分：0)
非常感谢Guyz， 这个问题现在解决了。 特别感谢JustWork
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.my_button).setOnClickListener(this);
txtUserName=(EditText)this.findViewById(R.id.editText1);
txtPassword=(EditText)this.findViewById(R.id.editText2);
}