我编写了一个名为GameView的自定义视图，它运行正常，很好地绘制了所有内容，但当我在XML中包含此自定义视图时，应用程序已运行，但自定义视图中没有任何内容被绘制出来。
以下代码：
GameView 类是 NewGame 的内部类
public class NewGame extends Activity {
GameView game_view;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
game_view = new GameView(this);
setContentView(R.layout.activity_new_game);
}
public static class GameView extends SurfaceView implements Runnable {
Thread game_thread = null;
// SurfaceHolder for Paint and Canvas in a thread
SurfaceHolder the_holder;
// Canvas and Paint objects
Canvas canvas;
Paint paint;
Bitmap dragon;
long fps; // tracks the game frame rate
private long time_this_frame; // calculate the fps
float x_position = 0; // start position
float y_position = 0;
long frame_ticker = 0l;
// New variables for spritesheet
private int frame_count = 10;
private int sprite_width = 600;
private int sprite_height = 450;
private int current_frame = 0; // Start at the first frame - where else?
// A rectangle to define an area of the sprite sheet that represents 1 frame
private Rect frame_to_draw = new Rect(0, 0, sprite_width, sprite_height);
// A rect that defines an area of the screen on which to draw
RectF where_to_draw = new RectF(x_position, 0, x_position + sprite_width, sprite_height);
// When the we initialize (call new()) on gameView
// This special constructor method runs
public GameView(Context context) {
super(context);
init(context);
}
public GameView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public GameView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
private void init(Context context) {
// Initialize ourHolder and paint objects
the_holder = getHolder();
paint = new Paint();
// Load dragon from .png file
dragon = BitmapFactory.decodeResource(this.getResources(), R.drawable.gd10_spritesheet);
}
@Override
public void run() {
while (true) {
// Capture the current time in milliseconds in startFrameTime
long startFrameTime = System.currentTimeMillis();
// Update the frame
update();
// Draw the frame
draw();
// Calculate the fps this frame
// We can then use the result to
// time animations and more.
time_this_frame = System.currentTimeMillis() - startFrameTime;
if (time_this_frame >= 1) {
fps = 5000 / time_this_frame;
}
}
}
// Everything that needs to be updated goes in here
// In later projects we will have dozens (arrays) of objects.
// We will also do other things like collision detection.
public void update() {
long game_time = System.currentTimeMillis();
if (game_time > (frame_ticker + fps)) {
frame_ticker = game_time;
current_frame++;
if (current_frame >= frame_count) {
current_frame = 0;
}
}
frame_to_draw.left = current_frame * sprite_width;
frame_to_draw.right = frame_to_draw.left + sprite_width;
}
// Draw the newly updated scene
public void draw() {
// Make sure our drawing surface is valid or we crash
if (the_holder.getSurface().isValid()) {
// Lock the canvas ready to draw
canvas = the_holder.lockCanvas();
//Log.d("test", "in if of draw()");
// Draw the background color
canvas.drawColor(Color.argb(255, 144, 195, 212));
// Choose the brush color for drawing
paint.setColor(Color.argb(255, 249, 129, 0));
x_position = (float) (this.getWidth()/2.0 - frame_to_draw.width()/2.0);
y_position = (float) (this.getHeight()/4.0 - frame_to_draw.height()/2.0);
where_to_draw.set((int) x_position,
(int) y_position,
(int) x_position + sprite_width,
(int) y_position + sprite_height);
canvas.drawBitmap(dragon,
frame_to_draw,
where_to_draw, paint);
// Draw everything to the screen
the_holder.unlockCanvasAndPost(canvas);
}
}
public void getCurrentFrame(){
long time = System.currentTimeMillis();
/*current_frame++;
if (current_frame >= frame_count)
current_frame = 0;*/
//update the left and right values of the source of
//the next frame on the spritesheet
frame_to_draw.left = current_frame * sprite_width;
frame_to_draw.right = frame_to_draw.left + sprite_width;
}
public void pause() {
try {
game_thread.join();
} catch (InterruptedException e) {
Log.e("Error:", "joining thread");
}
}
public void resume() {
game_thread = new Thread(this);
game_thread.start();
}
}
// This method executes when the player starts the game
@Override
protected void onResume() {
super.onResume();
// Tell the gameView resume method to execute
game_view.resume();
}
// This method executes when the player quits the game
@Override
protected void onPause() {
super.onPause();
// Tell the gameView pause method to execute
game_view.pause();
}
}
activity_new_game.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
tools:context="com.example.xuan.tictactoe.NewGame">
<view class="com.example.xuan.tictactoe.NewGame$GameView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
因此，当我执行此操作时它不起作用，但如果onCreate NewGame setContentView(game_view) if (the_holder.getSurface().isValid())，那么程序会运行并执行我想要的操作。我做了一些调试，发现当我在XML文件中包含自定义视图时，onDraw下GameView <script type="text/javascript">
var visitors = document.getElementById('tb254597').value;
function limitVisitors() {
if ( visitors > 60 ) {
alert("We can only accommodate 60 people on a group visit. You entered " + visitors + " visitors.");
}
}
</script>
下的Config.groovy返回false，所以事情不会得到。
不知道为什么它会返回false。我只想将自定义视图与XML中的一些小部件一起使用。有什么建议吗？谢谢！