Question

This is my code, what’s the matter?

Operation result is “has stopped unexpectedly”.
It can go through when remove the OnClickListener,that is say, that button to click on the binding is wrong?

gao.java

package cn.gao; 

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.*; 

public class gao<hellotwo> extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);  

        setContentView(R.layout.main); 
        Button btn=(Button)findViewById(R.id.go); 

        btn.setOnClickListener(new View.OnClickListener() 
        { 
                public void onClick(View v) 
                { 
                        EditText edt=(EditText)gao.this.findViewById(R.id.edt); 
                        TextView txt=(TextView)gao.this.findViewById(R.id.txt); 
                        txt.setText(getString(R.string.msg_dialog)+edt.getText()); 
                } 
        }); 
    } 
}

main.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    androidrientation="vertical" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    > 

<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"   
    /> 

<EditText id="@+id/edt" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="" 
/> 
<EditText id="@+id/txt" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="" 
/> 
<Button id="@+id/go" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:text="@string/go"> 
    <requestFocus /> 
</Button> 
</LinearLayout> 

strings.xml

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <string name="hello">hello android</string> 
    <string name="app_name">hellotwo</string> 
    <string name="tit_dialog">提示</string> 
    <string name="msg_dialog">你好，中国</string> 
    <string name="ok_dialog">确定</string> 
    <string name="go">浏览</string> 
</resources> 

Answer 1

Tested Code below,

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    > 

<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"   
    /> 

<EditText
    android:id="@+id/edt"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/edit"
    android:text="" />

<EditText
    android:id="@+id/txt"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/edit"
    android:text="" />

<Button
    android:id="@+id/go"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/go" >

    <requestFocus /> 
</Button> 
</LinearLayout> 

MainActivity.java:

package com.example.stackoverflow;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn=(Button)findViewById(R.id.go); 

        btn.setOnClickListener(new View.OnClickListener() 
        { 
                public void onClick(View v) 
                { 
                        EditText edt=(EditText)findViewById(R.id.edt); 
                        TextView txt=(TextView)findViewById(R.id.txt); 
                        txt.setText(getString(R.string.msg_dialog)+edt.getText()); 
                } 
        }); 
    }
}

string.xml:

<resources>    
    <string name="hello_world">Hello world!</string>
    <string name="menu_settings">Settings</string>
    <string name="title_activity_main">MainActivity</string>
    <string name="hello">hello android</string> 
    <string name="app_name">hellotwo</string> 
    <string name="tit_dialog">提示</string> 
    <string name="msg_dialog">你好，中国</string> 
    <string name="ok_dialog">确定</string> 
    <string name="go">浏览</string> 
    <string name="edit">Enter text</string> 
</resources>

Output:

Hope it will help you. 🙂