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我有一个加载了动画 gif 的 WebView。我还有一个倒数计时器，当它启动时，它会加载不同的动画 gif。

当计时器运行时，gif 不会动画。解决此问题的最佳方法是什么？

public class Practice extends SherlockActivity implements
    AnimationLayout.Listener {
public final static String TAG = "Practice";

protected ListView mList;
protected AnimationLayout mLayout;
protected String[] mStrings = { "Lesson 1", "Lesson 2", "Lesson 3",
        "Lesson 4", "Lesson 5", "Lesson 6", "Lesson 7", "Lesson 8",
        "Lesson 9", "Lesson 10" };
String[] lesson1;
String[] lesson2;
String[] lesson3;
String[] lesson4;
String[] lesson5;
String[] lesson6;
String[] lesson7;
String[] lesson8;
String[] lesson9;
String[] lesson10;
Button buttonA;
Button buttonB;
Button buttonC;
Button buttonD;
String[] prev;
int numCorrect;
int numWrong;
int i;
String answer;
static Random rnd;
Random r;
final String alphabet = "ABCD";
final int N = 4;
char letter = 'A';
String rand = " ";
int index;
WebView sign;
long mMilliseconds = 10000;
TextView score;

CountDownTimer mCountDownTimer = new CountDownTimer(mMilliseconds, 10){
    @Override
    public void onFinish() {
        score.setText("0");
    }

    public void onTick(long millisUntilFinished){
        score.setText(String.valueOf(millisUntilFinished/100));
    }
};
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_practice);

    prev = new String[100];
    rnd = new Random();
    r = new Random();
    score = (TextView) findViewById(R.id.textView1);

    lesson1 = getResources().getStringArray(R.array.lesson_1);
    lesson2 = getResources().getStringArray(R.array.lesson_2);
    lesson3 = getResources().getStringArray(R.array.lesson_3);
    lesson4 = getResources().getStringArray(R.array.lesson_4);
    lesson5 = getResources().getStringArray(R.array.lesson_5);
    lesson6 = getResources().getStringArray(R.array.lesson_6);
    lesson7 = getResources().getStringArray(R.array.lesson_7);
    lesson8 = getResources().getStringArray(R.array.lesson_8);
    lesson9 = getResources().getStringArray(R.array.lesson_9);
    lesson10 = getResources().getStringArray(R.array.lesson_10);

    rand = lesson1[rnd.nextInt(lesson1.length)];

    mLayout = (AnimationLayout) findViewById(R.id.animation_layout);
    mLayout.setListener(this);

    mList = (ListView) findViewById(R.id.sidebar_list);
    mList.setAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_multiple_choice, mStrings));
    mList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
    mList.setItemChecked(0, true);

    sign = new WebView(getApplicationContext());
    sign = (WebView) findViewById(R.id.webView1);

    buttonA = (Button) findViewById(R.id.option1_button);
    buttonB = (Button) findViewById(R.id.option2_button);
    buttonC = (Button) findViewById(R.id.option3_button);
    buttonD = (Button) findViewById(R.id.option4_button);

    setSign();
}

public void onClickContentButton(View v) {
    mLayout.toggleSidebar();
}

public void onClickA(View v) {
    if (answer == buttonA.getText().toString()) {
        numCorrect += 1;
    } else {
        numWrong += 1;
    }

    setSign();
}

public void onClickB(View v) {
    if (answer == buttonB.getText().toString()) {
        numCorrect += 1;
    } else {
        numWrong += 1;
    }

    setSign();
}

public void onClickC(View v) {
    if (answer == buttonC.getText().toString()) {
        numCorrect += 1;
    } else {
        numWrong += 1;
    }

    setSign();
}

public void onClickD(View v) {
    if (answer == buttonD.getText().toString()) {
        numCorrect += 1;
    } else {
        numWrong += 1;
    }

    setSign();
}

public void onClick(View view) {

}

@Override
public void onBackPressed() {
    if (mLayout.isOpening()) {
        mLayout.closeSidebar();
    } else {
        finish();
    }
}

@Override
public void onSidebarOpened() {
    Log.d(TAG, "opened");
}

@Override
public void onSidebarClosed() {
    Log.d(TAG, "opened");
}

@Override
public boolean onContentTouchedWhenOpening() {
    Log.d(TAG, "going to close sidebar");
    mLayout.closeSidebar();
    return true;
}

public void setSign() {

    answer = pickRandomAnswer(prev[i]);

    letter = alphabet.charAt(r.nextInt(N));

    sign.loadUrl("file:///android_asset/" + answer.toLowerCase() + ".html");

    prev[i] = answer;

    buttonA.setText(pickRandomAnswer(answer));
    buttonB.setText(pickRandomAnswer(buttonA.getText().toString()));
    buttonC.setText(pickRandomAnswer(buttonB.getText().toString()));
    buttonD.setText(pickRandomAnswer(buttonC.getText().toString()));

    if (letter == 'A')
        buttonA.setText(answer);
    if (letter == 'B')
        buttonB.setText(answer);
    if (letter == 'C')
        buttonC.setText(answer);
    if (letter == 'D')
        buttonD.setText(answer);

    if(i>= 95){
        i = 0;
    } else {
        i += 1;
    }
    mCountDownTimer.start();
}


public String pickRandomAnswer(String str) {

    do{
        index = rnd.nextInt(10+1);

        if(index == 1){
            if(mList.isItemChecked(0)){
                rand = lesson1[rnd.nextInt(lesson1.length)];
            }
        }

        if(index == 2){
            if(mList.isItemChecked(1)){
                rand = lesson2[rnd.nextInt(lesson2.length)];
            }
        }

        if(index == 3){
            if(mList.isItemChecked(2)){
                rand = lesson3[rnd.nextInt(lesson3.length)];
            }
        }

        if(index == 4){
            if(mList.isItemChecked(3)){
                rand = lesson4[rnd.nextInt(lesson4.length)];
            }
        }

        if(index == 5){
            if(mList.isItemChecked(4)){
                rand = lesson5[rnd.nextInt(lesson5.length)];
            }
        }

        if(index == 6){
            if(mList.isItemChecked(5)){
                rand = lesson6[rnd.nextInt(lesson6.length)];
            }
        }

        if(index == 7){
            if(mList.isItemChecked(6)){
                rand = lesson7[rnd.nextInt(lesson7.length)];
            }
        }

        if(index == 8){
            if(mList.isItemChecked(7)){
                rand = lesson8[rnd.nextInt(lesson8.length)];
            }
        }

        if(index == 9){
            if(mList.isItemChecked(8)){
                rand = lesson9[rnd.nextInt(lesson9.length)];
            }
        }

        if(index == 10){
            if(mList.isItemChecked(9)){
                rand = lesson10[rnd.nextInt(lesson10.length)];
            }
        }

    } while ( rand.contains("Grammar")| rand == str);
    return rand;
}

static void shuffleArray(String[] words) {
    for (int i = words.length - 1; i >= 0; i--) {
        int index = rnd.nextInt(i + 1);
        String a = words[index];
        words[index] = words[i];
        words[i] = a;
    }
}
}
4

2 回答 2

0

查看您的代码后，您的问题的一个可能原因是您TextView在每次onTick()调用CountDownTimer. 文档CountDownTimer只提到它是“定期”调用的，所以我不确定它被调用的频率，但在我看来，你不应该在每次onTick()调用时做一些更新 UI 的事情，尤其是当你有WebView一个 gif 动画（一个相当资源密集型的任务）。onTick()我建议在你的方法中这样做：

public void onTick(long millisUntilFinished){
   if (mLastMillisUntilFinished == 0 ||
       mLastMillisUntilFinished - millisUntilFinished > UI_UPDATE_INTERVAL) {
       score.setText(String.valueOf(millisUntilFinished/UI_UPDATE_INTERVAL));
       mLastMillisUntilFinished = millisUntilFinished;
   }
}

这样，您只需每UI_UPDATE_INTERVAL毫秒更新一次 UI（只需将其定义为您想要的间隔，例如在您的情况下为 100 以每 10 秒更新一次）。这可以保护您避免过于频繁地更新 UI，并允许WebView您完成它的工作。

作为最后的手段，有一个更复杂（不太复杂）的解决方案可以让您获得所需的性能。GifView在我的一个 github 存储库中查看此类：

https://github.com/bduncavage/catoverflow/blob/master/src/jp/tomorrowkey/android/gifplayer/GifView.java

我在 google code 的一个废弃项目中找到了该类，并将其用于需要我将动画 gif 绘制到 Canvas 的项目中。它需要认真的工作，因为它根本不是线程安全的，而且它占用内存，但是，它确实有效。

您可以非常轻松地使用 GifView，它应该比使用 WebView 来制作 gif 动画要快得多。您还需要GifDecoder类。

干杯。

于 2013-04-04T05:39:08.750 回答
0

作为最后的手段，我想说你也可以将你的 GIF 分割成帧，然后使用 drawables 在 android 中渲染它们。 绘图参考

于 2013-04-05T12:53:34.683 回答