我正在尝试运行此程序。在logcat或构建期间没有显示错误。但我在设备上收到错误：
不幸的是我的应用已停止工作了。
我如何克服这个问题？
// activity.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:background="#daf1ff">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="USER REGISTRATION"
android:textSize="30dp"
android:layout_marginBottom="20dp"
android:layout_marginLeft="22dp"
android:textColor="#ed2d26"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp">
<TextView android:text="Name: "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:textColor="#fd7214"/>
<EditText
android:layout_width="250dp"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp">
<TextView android:text="Gender: "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:layout_marginRight="20dp"
android:textColor="#fd7214"/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Male"
android:textColor="#a61f82"
android:textSize="20dp"
android:layout_marginLeft="10dp"/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Female"
android:textColor="#a61f82"
android:textSize="20dp"/>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp">
<TextView android:text="Country: "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:textColor="#fd7214"
android:layout_marginRight="20dp"/>
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/spinner1"
android:layout_marginTop="20dp">
</Spinner>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp">
<TextView android:text="Address: "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:layout_marginRight="20dp"
android:textColor="#fd7214"/>
<EditText
android:layout_width="250dp"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp">
<TextView android:text="Phone No: +91 "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:textColor="#fd7214"
/>
<EditText
android:layout_width="150dp"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="50dp">
<TextView android:text="E-mail: "
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:textColor="#fd7214"
/>
<EditText
android:layout_width="86dp"
android:layout_height="wrap_content" />
<Spinner
android:layout_width="100dp"
android:layout_height="wrap_content"
android:id="@+id/spinner2"
android:layout_marginTop="20dp">
</Spinner>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=".com "
android:textSize="20dp"
android:textColor="#ff0080"/>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="REGISTER"
android:textSize="25dp"
android:layout_marginRight="70dp"
android:id="@+id/register"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CANCEL"
android:textSize="25dp"
android:id="@+id/cancel"/>
</LinearLayout>
</LinearLayout>
</RelativeLayout>
// MainActivity.java
package com.example.sreelakshmi.myuser;
import android.app.Activity;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;
public class MainActivity extends Activity implements AdapterView.OnItemSelectedListener {
String[] country=new String[]{"India","Japan","Canada","US","Others"};
String[] mailid=new String[]{"@ gmail","@ yahoo","@ rediffmail","@ hotmail","@ godrej"};
Spinner spin1=(Spinner)findViewById(R.id.spinner1);
Spinner spin2=(Spinner)findViewById(R.id.spinner2);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayAdapter a1=new ArrayAdapter(this,android.R.layout.simple_spinner_dropdown_item,country);
a1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spin1.setAdapter(a1);
ArrayAdapter a2=new ArrayAdapter(this,android.R.layout.simple_spinner_dropdown_item,mailid);
a2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spin2.setAdapter(a2);
Button b1=(Button)findViewById(R.id.register);
Button b2=(Button)findViewById(R.id.cancel);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),"Registration Successful!",Toast.LENGTH_LONG).show();
}
});
b2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
spin1.setOnItemSelectedListener(this);
spin2.setOnItemSelectedListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
switch(arg0.getId()){
case R.id.spinner1 :
Toast.makeText(getApplicationContext(),country[arg2],Toast.LENGTH_LONG).show();
break;
case R.id.spinner2 :
//Your Another Action Here.
Toast.makeText(getApplicationContext(),mailid[arg2],Toast.LENGTH_LONG).show();
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
答案 0 :(得分：2)
angularJS必须在Spinner spin1=(Spinner)findViewById(R.id.spinner1);
Spinner spin2=(Spinner)findViewById(R.id.spinner2);
之后onCreate
setContentView findViewById你没有小工具可以找到，拨打电话setContentView，不必要答案 1 :(得分：0)
刚刚在我的代码中进行了此更改并且运行良好。 。 。 。
final Spinner spin1=(Spinner)findViewById(R.id.spinner1);
ArrayAdapter a1=new ArrayAdapter(this,android.R.layout.simple_spinner_dropdown_item,country);
a1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spin1.setAdapter(a1);
final Spinner spin2=(Spinner)findViewById(R.id.spinner2);
ArrayAdapter a2=new ArrayAdapter(this,R.layout.first,R.id.text1,mailid);
spin2.setAdapter(a2);
.
.
.
.
spin1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(getApplicationContext(), spin1.getSelectedItem().toString(), Toast.LENGTH_LONG).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
spin2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(getApplicationContext(), spin2.getSelectedItem().toString(), Toast.LENGTH_LONG).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
。 。 。 。