我有一个表面视图，将图像作为我的画布的背景，另一个作为拖放图像放在第一张图片的顶部。我的代码部分工作正常（除了在我触摸它时启动屏幕是黑色的）然后出现背景图像，一切正常。此活动在没有setContentView调用的情况下全屏运行，因此我想使用活动布局添加按钮以启动下一个活动。
的setContentView（R.layout.image_edit_activity）;
public class ImageEditActivity extends Activity {
public String reportDate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.image_edit_activity);
Intent intent = getIntent();
reportDate = intent.getStringExtra("reportDate");
int w=getWindowManager().getDefaultDisplay().getWidth()-25;
int h=getWindowManager().getDefaultDisplay().getHeight()-25;
Crosshair crosshairView = new Crosshair(this,w,h, reportDate);
//app works fine without this line, but I think this is the key to
//have the surfaceview inside the activity layout.xml
crosshairView = (Crosshair) findViewById(R.id.surfaceView);
}
}
class Crosshair extends SurfaceView implements SurfaceHolder.Callback {
private Bitmap bitmap ;
private int x=20,y=20;int width,height;
String reportDate1;
public Crosshair(Context context,int w,int h, String reportDate) {
super(context);
reportDate1 = reportDate;
width=w;
height=h;
getHolder().addCallback(this);
setFocusable(true);
}
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/VibrationMeasurement/" + reportDate1 + ".machine" + ".jpg";
Bitmap bitmap2 = BitmapFactory.decodeFile(path);
Bitmap scaled = Bitmap.createScaledBitmap(bitmap2, width, height, true);
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.crosshair);
// canvas.drawColor(Color.BLUE);//To make background
canvas.drawBitmap(scaled,0,0,null);
canvas.drawBitmap(bitmap,x-(bitmap.getWidth()/2),y-(bitmap.getHeight()/2),null);
// canvas.drawBitmap(;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
x=(int)event.getX();
y=(int)event.getY();
if(x<25)
x=25;
if(x> width)
x=width;
if(y <25)
y=25;
if(y > height)
y=height;
updateCrosshair();
return true;
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
private void updateCrosshair() {
Canvas canvas = null;
try {
canvas = getHolder().lockCanvas(null);
synchronized (getHolder()) {
this.onDraw(canvas);
}
}
finally {
if (canvas != null) {
getHolder().unlockCanvasAndPost(canvas);
}
}
}
}
这是xml文件：
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<com.effbe.accelerometer.ImageEditActivity.Crosshair
android:id="@+id/surfaceView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="114dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="@drawable/ok_button"
android:padding="10dp"
android:paddingLeft="10dip"
android:text="OK"
android:textColor="#ffffff" />
</LinearLayout>
当我尝试运行应用程序时，它会为Crosshair类抛出NoClassDefFoundError。
logcat的
04-23 21:12:28.618: E/AndroidRuntime(27487): FATAL EXCEPTION: main
04-23 21:12:28.618: E/AndroidRuntime(27487): Process: com.effbe.accelerometer
04-23 21:12:28.618: E/AndroidRuntime(27487): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.effbe.accelerometer/com.effbe.accelerometer.ImageEditActivity}: android.view.InflateException: Binary XML file line #6: Error inflating class com.effbe.accelerometer.ImageEditActivity.Crosshair
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487): Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class com.effbe.accelerometer.ImageEditActivity.Crosshair
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487):
04-23 21:12:28.618: E/AndroidRuntime(27487): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.effbe.accelerometer.ImageEditActivity.Crosshair" on path: DexPathList[[zip file "/data/app/com.effbe.accelerometer-1.apk"]
答案 0 :(得分：0)
每次使用xml类时都需要三个构造函数。
public Crosshair(Context context) {
super(context);
init(context);
}
public Crosshair(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public Crosshair(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}