这是代码: public class beautiful extends Activity { ImageView radar =(ImageView)findViewById(R.id.radar);
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.beautiful);
Button search = (Button) findViewById(R.id.magnifier);
ImageView text = (ImageView) findViewById(R.id.text);
MediaPlayer siren = MediaPlayer.create(this, R.raw.siren);
search.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Thread counter = new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
try{
Thread.sleep(2000);
radar.setImageResource(R.drawable.radar_new_full);
Thread.sleep(3000);
radar.setImageResource(R.drawable.radar_new_50);
Thread.sleep(2000);
radar.setImageResource(R.drawable.radar_new_found);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
}
}
});
counter.start();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// TODO Auto-generated method stub
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
// TODO Auto-generated method stub
switch(item.getItemId()){
case R.id.new_search:
startActivity(new Intent("com.zwiebel.MENU"));
}
return super.onMenuItemSelected(featureId, item);
}
}
这是布局:
<?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"
android:background="#fccea8">
<Button
android:id="@+id/magnifier"
android:layout_width="25dp"
android:layout_height="25dp"
android:layout_gravity="right"
android:background="@drawable/searchmagnificer"
/>
<ImageView
android:id="@+id/radar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingTop="5dp"
/>
<ImageView
android:id="@+id/text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
/>
</LinearLayout>
我在代码中没有看到任何问题,所以我不知道错误是什么。
答案 0 :(得分:6)
很明显。您正在尝试在设置视图之前查找视图。
ImageView radar = (ImageView) findViewById(R.id.radar);
将其更改为
ImageView radar;
并放
radar = (ImageView) findViewById(R.id.radar);
在setContentView函数
下面