在我的 Android 应用程序中,我试图一个一个地显示字母,每个字母之间有短暂的延迟,同时还为每个字母播放声音。我一切正常,声音以正确的延迟播放,但文本总是以太快的速度打印到屏幕上。即使我没有专门使视图无效,画布似乎也已更新。
这是我到目前为止所拥有的 - 我还尝试了基于“蛇”示例的变体并得到了相同的结果......任何帮助将不胜感激!
public class SpellingView extends View {
private static final String WORD = "TRUCK";
int width;
int height;
String textToPrint;
float textspace;
int j=0;
private final Path arc;
private final Paint tPaint;
//constructor for SpellingView
public SpellingView(Context context) {
super(context);
arc = new Path();
tPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
displayLetterLoop();
}
public void displayLetterLoop(){
for (int i = 0; i < WORD.length(); i++){
final Runnable mUpdateUITimerTask = new Runnable() {
public void run() {
Spelling.mp.start();
}
};
final Handler mHandler = new Handler();
mHandler.postDelayed(mUpdateUITimerTask, i*1500);
}
}
@Override
protected void onDraw(Canvas canvas) {
int k;
// Drawing commands go here
width = canvas.getWidth();
height = canvas.getHeight();
arc.addArc(new RectF((width*.15f), (height*.15f), (width*.85f), (height*.4f)), 180,180);
tPaint.setStyle(Paint.Style.FILL_AND_STROKE);
tPaint.setColor(Color.RED);
tPaint.setTextSize(height * 0.1f);
tPaint.setTextAlign(Paint.Align.LEFT);
setBackgroundColor(Color.BLACK);
for (k = 0; k < j; k++){
char c = WORD.charAt(k);
String cs = Character.toString(c);
textToPrint+= cs;
textspace =(float) (k*(width/WORD.length())*.9);
canvas.drawTextOnPath(cs, arc, textspace , 0, tPaint);
}
if(j<WORD.length()){
j++;
}
}
}