很抱歉再次烦恼，我试图设置一个圆形菜单的背景我已经做了，但应用程序崩溃，我已经尝试了几次，但我还没弄明白。你能帮帮我吗？
TestMenuActivity.java
package com.example.circlemenu;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.RelativeLayout;
import android.widget.Spinner;
import android.widget.Toast;
public class TestMenuActivity extends Activity {
CircleView cView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View pruebafondo = findViewById(R.id.pruebafondo);
pruebafondo.setBackgroundResource(R.drawable.circle);
int numberOfElements = 6;
View[] elems = new View[numberOfElements];
ImageButton tv = new ImageButton(this);
tv.setBackgroundResource(R.drawable.images1);
tv.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[0] = tv;
tv.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
Toast t = Toast.makeText(getBaseContext(), "Enviar correo a un Socio",
Toast.LENGTH_SHORT);
t.show();
}
});
tv.setOnLongClickListener(new OnLongClickListener(){
public boolean onLongClick(View arg0){
Intent intent = new Intent(TestMenuActivity.this, prueba.class);
startActivity(intent);
return true;
}
});
ImageButton tv1 = new ImageButton(this);
tv1.setBackgroundResource(R.drawable.imagen2);
tv1.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[1] = tv1;
ImageButton tv2 = new ImageButton(this);
tv2.setBackgroundResource(R.drawable.image3);
tv2.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[2] = tv2;
ImageButton tv3 = new ImageButton(this);
tv3.setBackgroundResource(R.drawable.imagen4);
tv3.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[3] = tv3;
ImageButton tv4 = new ImageButton(this);
tv4.setBackgroundResource(R.drawable.imagen5);
tv4.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[4] = tv4;
ImageButton tv5 = new ImageButton(this);
tv5.setBackgroundResource(R.drawable.image6);
tv5.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
elems[numberOfElements - 1] = tv5;
cView = new CircleView(this, 115, elems);
setContentView(cView);
}
}
CircleView.java
package com.example.circlemenu;
import android.content.Context;
import android.view.View;
import android.widget.RelativeLayout;
public class CircleView extends RelativeLayout {
static final int centerId = 111;
private final int radius;
private RelativeLayout.LayoutParams createNewRelativeLayoutParams() {
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT);
lp.addRule(RelativeLayout.ABOVE, centerId);
lp.addRule(RIGHT_OF, centerId);
return lp;
}
private View prepareElementForCircle(View elem, int distX, int distY) {
RelativeLayout.LayoutParams lp = createNewRelativeLayoutParams();
elem.measure(0, 0);
int deltaX = elem.getMeasuredWidth() / 2;
int deltaY = elem.getMeasuredHeight() / 2;
lp.setMargins(distX - deltaX, 0, 0, radius - distY - deltaY);
elem.setLayoutParams(lp);
return elem;
}
public CircleView(Context context, int radius, View[] elements) {
super(context);
this.radius = radius;
RelativeLayout.LayoutParams lpView = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT);
this.setLayoutParams(lpView);
View center = new View(context);
center.setId(centerId);
RelativeLayout.LayoutParams lpcenter = new RelativeLayout.LayoutParams(
0, 0);
lpcenter.addRule(CENTER_HORIZONTAL);
lpcenter.addRule(CENTER_VERTICAL);
center.setLayoutParams(lpcenter);
this.addView(center);
this.addView(prepareElementForCircle(elements[0], 0, 0));
if (elements.length % 2 == 0) {
this.addView(prepareElementForCircle(elements[elements.length / 2],
0, 2 * radius));
}
if (elements.length > 2) {
for (int i = 1; i <= (elements.length - 1) / 2; i++) {
int y = i * 4 * radius / elements.length;
int x = (int) Math.sqrt(Math.pow(radius, 2)
- Math.pow((radius - y), 2));
this.addView(prepareElementForCircle(elements[i], x, y));
this.addView(prepareElementForCircle(elements[elements.length
- i], -x, y));
}
}
}
}
activity_test_menu.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/pruebafondo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:background="@drawable/circle"
tools:context=".TestMenuActivity" >
</RelativeLayout>
logcat的：
01-29 09:08:12.303: W/dalvikvm(771): threadid=1: thread exiting with uncaught exception (group=0x41465700)
01-29 09:08:12.313: E/AndroidRuntime(771): FATAL EXCEPTION: main
01-29 09:08:12.313: E/AndroidRuntime(771): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.circlemenu/com.example.circlemenu.TestMenuActivity}: java.lang.NullPointerException
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.os.Handler.dispatchMessage(Handler.java:99)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.os.Looper.loop(Looper.java:137)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread.main(ActivityThread.java:5103)
01-29 09:08:12.313: E/AndroidRuntime(771): at java.lang.reflect.Method.invokeNative(Native Method)
01-29 09:08:12.313: E/AndroidRuntime(771): at java.lang.reflect.Method.invoke(Method.java:525)
01-29 09:08:12.313: E/AndroidRuntime(771): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
01-29 09:08:12.313: E/AndroidRuntime(771): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-29 09:08:12.313: E/AndroidRuntime(771): at dalvik.system.NativeStart.main(Native Method)
01-29 09:08:12.313: E/AndroidRuntime(771): Caused by: java.lang.NullPointerException
01-29 09:08:12.313: E/AndroidRuntime(771): at com.example.circlemenu.TestMenuActivity.onCreate(TestMenuActivity.java:29)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.Activity.performCreate(Activity.java:5133)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
01-29 09:08:12.313: E/AndroidRuntime(771): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
01-29 09:08:12.313: E/AndroidRuntime(771): ... 11 more