我正在尝试使用（View.Invisible）隐藏2个LinearLayouts。 LinearLayouts分别有1-1个文本视图。有什么建议？下面我附上了MainActivity类，AsyncTask类和Logcat文本。当我试图将LinearLayouts添加到Arraylist时，我得到了错误（我已经研究了很多：P ...评论它不会出错）...提前致谢
MainActivity
package com.abhishek.ally2;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
TextView textview;
String header;
Handler handler;
ImageView image ;
asyncNetwork task = null;
ProgressBar pg;
List<String> response = null;
List<LinearLayout> ll =new ArrayList<LinearLayout>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
handler = new Handler();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void login(View v)
{
boolean check = true;
String id = null;
int length;
textview = (TextView)findViewById(R.id.allyId);
if(textview.getText().length() == 0)
{
Toast.makeText(this, "Enter Ally ID", Toast.LENGTH_LONG).show();
check = false;
}
for (char c : textview.getText().toString().toCharArray())
{
if (!Character.isDigit(c))
{
Toast.makeText(this, "Invalid Input", Toast.LENGTH_LONG).show();
check = false;
break;
}
}
if(check)
{
id = textview.getText().toString();
id = "id="+id;
length = id.length();
setContentView(R.layout.activity_main);
pg = (ProgressBar)findViewById(R.id.progressBar1);
textview = (TextView)findViewById(R.id.status);
image = (ImageView)findViewById(R.id.imageFrnds);
ll.add((LinearLayout)findViewById(R.id.emailll1));
ll.add((LinearLayout)findViewById(R.id.smsll1));
image.setImageResource(R.drawable.ally);
task = new asyncNetwork(this, textview, new Handler(), image, pg, ll);
task.execute("easyvote.co.in", "80", "POST /ally.php HTTP/1.0\nHost: easyvote.co.in\nContent-Type: application/x-www-form-urlencoded\nContent-Length: "+ length +"\n\n" + id + "\n");
}
}
}
asyncNetwork.java
/**
*
*/
package com.abhishek.ally2;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;
public class asyncNetwork extends AsyncTask<String, Void, String>{
Context myCtx;
Friend friend ;
TextView status;
ImageView image;
private Handler handler;
private Runnable r;
String responseLine;
List<String> response = null;
List<LinearLayout> ll = null;
ProgressBar pg;
boolean data = false;
asyncNetwork(Context context, TextView status, Handler handler, ImageView image, ProgressBar pg, List<LinearLayout> ll)
{
this.myCtx = context;
this.status = status;
this.handler = handler;
this.data = false;
this.image = image;
this.pg = pg;
this.ll = ll;
}
@Override
protected String doInBackground(String... mainData) {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String host = mainData[0];
int port = Integer.parseInt(mainData[1]);
String data = mainData[2];
Socket client = null;
DataOutputStream os = null;
BufferedReader is = null;
try
{
while(true)
{
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
this.response = new ArrayList<String>();
this.data = false;
client = new Socket(host, port);
os = new DataOutputStream(client.getOutputStream());
is= new BufferedReader(new InputStreamReader(client.getInputStream(), "iso-8859-1"), 8);
if(client != null && os != null && is != null)
{
//Log.d("Response", data);
os.writeBytes(data);
responseLine = is.readLine();
if(!responseLine.contains("200"))
{
r = new Runnable(){
@Override
public void run() {
status.setText("404 Error :(");
}
};
this.handler.post(r);
}
while((responseLine = is.readLine()) != null)
{
Log.d("Response", responseLine);
if(this.data)
{
response.add(responseLine);
}
if(responseLine.contains("###start"))
{
this.data = true;
}
}
os.close();
is.close();
client.close();
Log.d("Count value", "value" + response.size());
friend = new Friend(response.get(0));
if(friend.isOnline())
{
Log.d("Count value", friend.name + " is online :)");
//status.setText(friend.name + " is online :)");
r = new Runnable(){
@Override
public void run() {
status.setText(friend.name + " is Online :)");
image.setImageResource(R.drawable.tapus);
pg.setVisibility(View.INVISIBLE);
}
};
this.handler.post(r);
}
else
{
Log.d("Count value", friend.name + " is Offline :)");
r = new Runnable(){
@Override
public void run() {
image.setImageResource(R.drawable.tapus);
status.setText(friend.name + " is Offline :(");
pg.setVisibility(View.VISIBLE);
//ll[0].setVisibility(View.VISIBLE);
//ll[1].setVisibility(View.VISIBLE);
}
};
this.handler.post(r);
}
}
}
}
catch (UnknownHostException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}
Logcat数据
07-04 22:39:19.875: E/AndroidRuntime(446): FATAL EXCEPTION: main
07-04 22:39:19.875: E/AndroidRuntime(446): java.lang.IllegalStateException: Could not execute method of the activity
07-04 22:39:19.875: E/AndroidRuntime(446): at android.view.View$1.onClick(View.java:2072)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.view.View.performClick(View.java:2408)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.view.View$PerformClick.run(View.java:8816)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.os.Handler.handleCallback(Handler.java:587)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.os.Handler.dispatchMessage(Handler.java:92)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.os.Looper.loop(Looper.java:123)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-04 22:39:19.875: E/AndroidRuntime(446): at java.lang.reflect.Method.invokeNative(Native Method)
07-04 22:39:19.875: E/AndroidRuntime(446): at java.lang.reflect.Method.invoke(Method.java:521)
07-04 22:39:19.875: E/AndroidRuntime(446): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-04 22:39:19.875: E/AndroidRuntime(446): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-04 22:39:19.875: E/AndroidRuntime(446): at dalvik.system.NativeStart.main(Native Method)
07-04 22:39:19.875: E/AndroidRuntime(446): Caused by: java.lang.reflect.InvocationTargetException
07-04 22:39:19.875: E/AndroidRuntime(446): at com.abhishek.ally2.MainActivity.login(MainActivity.java:70)
07-04 22:39:19.875: E/AndroidRuntime(446): at java.lang.reflect.Method.invokeNative(Native Method)
07-04 22:39:19.875: E/AndroidRuntime(446): at java.lang.reflect.Method.invoke(Method.java:521)
07-04 22:39:19.875: E/AndroidRuntime(446): at android.view.View$1.onClick(View.java:2067)
07-04 22:39:19.875: E/AndroidRuntime(446): ... 11 more
07-04 22:39:19.875: E/AndroidRuntime(446): Caused by: java.lang.ClassCastException: android.widget.TextView
07-04 22:39:19.875: E/AndroidRuntime(446): ... 15 more
答案 0 :(得分：0)
错误似乎出现在这两行
中 ll.add((LinearLayout)findViewById(R.id.emailll1));
ll.add((LinearLayout)findViewById(R.id.smsll1));
您正在尝试将View转换为LinearLayout，并且通过logcat它们似乎是TextViews（至少第一个会抛出错误）。
如果是这种情况，那么您需要将此处添加的内容更改为ArrayList，以添加您拥有的实际LinearLayout。