Question

我已经搜索了几个小时的解决方案，但找不到一个。我正在尝试创建一个自定义TextView，如果它是数字，它会动画值。但是，我甚至在它开始第一个值之前就得到了一个例外。我希望你能提供帮助。

这是我的代码：

import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.widget.TextView;

public class AnimatedValueTextView extends TextView {
    private static final int DURATION = 900;
    private float actualValue;
    private ValueAnimator animator;

    public AnimatedValueTextView(Context context) {
        super(context);
        init();
    }

    public AnimatedValueTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public AnimatedValueTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }


    private void init()
    {
        actualValue = 0;
        animator = new ValueAnimator();

        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator valueAnimator) {
                setText(valueAnimator.getAnimatedValue().toString());
                actualValue = (Float)valueAnimator.getAnimatedValue();
            }
        });

        animator.setDuration(DURATION);
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);

        boolean validValue = true;
        float newValue = 0;

        try {
            newValue = Float.parseFloat(this.getText().toString());
        }

        catch (Exception e)
        {
            validValue = false;
        }

        if(validValue)
        {
            if(animator == null)
            {
                init();
            }

            animator.cancel();
            animator.setFloatValues(actualValue, newValue);
            animator.start();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

我的XML

<com.---.-------.AnimatedValueTextView
            android:id="@+id/actualPressure"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            style="@style/FunkyTextBig"
            android:paddingLeft="2dp"
            android:text="1043"/>

和LogCat

01-16 09:55:14.954    5085-5085/com.---.----- E/AndroidRuntime﹕ FATAL EXCEPTION: main
    android.view.InflateException: Binary XML file line #18: Error inflating class com.---.-----.AnimatedValueTextView
            at android.view.LayoutInflater.createView(LayoutInflater.java:620)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:758)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
            at com.---.-----.ForecastFragment.onCreateView(ForecastFragment.java:70)
            at android.app.Fragment.performCreateView(Fragment.java:1695)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1057)
            at android.app.BackStackRecord.run(BackStackRecord.java:682)
            at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
            at android.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:474)
            at android.support.v13.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:167)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
            at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
            at android.view.View.measure(View.java:15848)
            at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
            at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
            at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
            at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905)
            at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
            at android.view.Choreographer.doCallbacks(Choreographer.java:562)
            at android.view.Choreographer.doFrame(Choreographer.java:532)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
            at android.os.Handler.handleCallback(Handler.java:730)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.reflect.InvocationTargetException
            at java.lang.reflect.Constructor.constructNative(Native Method)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
            at android.view.LayoutInflater.createView(LayoutInflater.java:594)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:758)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
            at com.---.-----.ForecastFragment.onCreateView(ForecastFragment.java:70)
            at android.app.Fragment.performCreateView(Fragment.java:1695)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1057)
            at android.app.BackStackRecord.run(BackStackRecord.java:682)
            at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
            at android.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:474)
            at android.support.v13.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:167)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
            at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
            at android.view.View.measure(View.java:15848)
            at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
            at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
            at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
            at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189)
            at android.view.View.measure(View.java:15848)
            at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905)
            at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
            at android.view.Choreographer.doCallbacks(Choreographer.java:562)
            at android.view.Choreographer.doFrame(Choreographer.java:532)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
            at android.os.Handler.handleCallback(Handler.java:730)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.StackOverflowError
            at java.lang.RealToString.floatToString(RealToString.java:126)
            at java.lang.Float.toString(Float.java:322)
            at java.lang.Float.toString(Float.java:310)

使用的风格：

<style name="FunkyTextBig" parent="@android:style/TextAppearance">
        <item name="android:textColor">#eaf1f7</item>
        <item name="android:textStyle">bold</item>
        <item name="android:shadowColor">#000000</item>
        <item name="android:shadowRadius">13</item>
        <item name="android:textSize">45sp</item>
        <item name="android:shadowDx">0</item>
        <item name="android:shadowDy">0</item>
    </style>

    <style name="FunkyTextMedium" parent="@style/FunkyTextBig">
        <item name="android:textSize">22sp</item>
    </style>

Answer 1

您收到此错误是因为您正在循环设置文本。

1）调用onTextChanged以保存初始值

2）onTextChanged中的代码开始动画，并在每一步调用setText（自动调用onTextChanged）

3）此onTextChanged将取消动画并重新开始。

解决方案是通过标志来控制onTextChanged的调用，为Animation添加另一个监听器：

animator.addListener(new Animator.AnimatorListener(){
    public void onAnimationStart(Animator animation) {
        isAnimating = true;
    }
    public void onAnimationEnd(Animator animation) {
        isAnimating = false;
    }
    public void onAnimationRepeat(Animator animation) {}
    public void onAnimationCancel(Animator animation) {}
})


@Override
protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
    if (isAnimating) return;
    super.onTextChanged(text, start, lengthBefore, lengthAfter);

    ...
}

Answer 2

另一个不错的解决方案是不覆盖onTextChanged方法，并且有两个方法setText：一个将触发动画的公共方法，以及一个将在没有动画的情况下更改值的私有方法：

private void init(){
    actualValue = 0;
    animator = new ValueAnimator();
    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            setTextInternal(valueAnimator.getAnimatedValue().toString());
            actualValue = (Float)valueAnimator.getAnimatedValue();
        }
    });

    animator.setDuration(DURATION);
}


public void setNumber(float newValue){
    animator.cancel();
    animator.setFloatValues(actualValue, newValue);
    animator.start();
}

public void setText(String txt){
    try {
        float newValue = Float.parseFloat(txt);
        setNumber(newValue);
    }catch (Exception e){
        super.setText(txt);
    }
}


private void setTextInternal(String txt){
    super.setText(txt);
}

Answer 3

在onTextChanged方法中，您正在启动animator，而setText()又会再次调用onTextChanged，这又会再次触发onTextChanged，这将永远持续下去，直到VM足够了。

如果您按如下方式更改@Override protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) { super.onTextChanged(text, start, lengthBefore, lengthAfter); if (animator != null && (animator.isStarted() || animator.isRunning())) return; // rest as above方法，则可以：

{{1}}

在Android中自定义TextView时出错

3 个答案: