旋转图像。动画列表或动画旋转？ （安卓） [英] Rotating image. Animation list or animated rotate? (Android)

问题描述

我想创建一个旋转的进步形象，不知道是继续进行的最佳方式。我可以把它与动画列表，例如12幅改变每100ms工作。这工作得很好，但它是相当繁琐的创建12图像或每一个的大小和分辨率：

I want to create a rotating progress image, and wonder what's the best way to proceed. I can make it work with an animation list with for example 12 images changing every 100ms. This works fine, but it's quite tedious to create 12 images or for every size and resolution:

<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:oneshot="false">
<item android:drawable="@drawable/ic_loading_grey_on_black_01" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_02" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_03" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_04" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_05" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_06" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_07" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_08" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_09" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_10" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_11" android:duration="100" />
<item android:drawable="@drawable/ic_loading_grey_on_black_12" android:duration="100" />

我假定一个更简单的解决方法是使用一个图像单位分辨率，而是将其旋转对每一帧。在平台资源（Android的SDK-窗口/平台...）我发现了一些所谓的动画，旋转在文件绘制/ search_spinner.xml，但如果我复制code得到一个编译错误抱怨安卓framesCount和android：frameDuration（谷歌的API在Eclipse 2.2）：

I suppose that an easier solution is to use one image per resolution, but rather rotate it for each frame. In the platform resources (android-sdk-windows/platforms...) I found something called animated-rotate in the file drawable/search_spinner.xml, but if I copy the code get a compiler error complaining about android:framesCount and android:frameDuration (Google APIs 2.2 in Eclipse):

<animated-rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:drawable="@drawable/spinner_black_20"
android:pivotX="50%"
android:pivotY="50%"
android:framesCount="12"
android:frameDuration="100" />

我也尝试过使用的重复旋转动画（使用动画资源文件夹），但我其实preFER的动画列表版本的外观。

I have also tried using a repeating rotate animation (using in the anim resource folder), but I actually prefer the look of the animation list version.

什么是解决这个问题的推荐方法？

What is the recommended way of solving this problem?

推荐答案

旋转绘制由普利文认为不会放弃的帧计数你的控制。让我们假设你想实现一个自定义加载器由来自8个部分：

Rotate drawable suggested by Praveen won't give you control of frame count. Let's assume you want to implement a custom loader which consists from 8 sections:

使用动画列表的办法，你需要创建8张由旋转45 * frameNumber的手动度。另外，您也可以使用第1帧，并设置旋转动画吧：

Using animation-list approach, you need to create 8 frames rotated by 45*frameNumber degrees manually. Alternatively, you can use 1st frame and set rotation animation to it:

文件 RES /动画/ progress_anim.xml ：

<?xml version="1.0" encoding="utf-8"?>
<rotate
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360"
    android:pivotX="50%"
    android:pivotY="50%"
    android:repeatCount="infinite" />

文件 MainActivity.java

Animation a = AnimationUtils.loadAnimation(getContext(), R.anim.progress_anim);
a.setDuration(1000);
imageView.startAnimation(a);

这将给你流畅的动画，而不是8阶梯。为了解决这个问题，我们需要实现自定义的内插器：

This will give you smooth animation instead of 8-stepped. To fix this we need to implement custom interpolator:

a.setInterpolator(new Interpolator() {
    private final int frameCount = 8;

    @Override
    public float getInterpolation(float input) {
        return (float)Math.floor(input*frameCount)/frameCount;
    }
});

你也可以创建一个自定义窗口小部件：

Also you can create a custom widget:

文件 RES /价值/ attrs.xml ：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ProgressView">
        <attr name="frameCount" format="integer"/>
        <attr name="duration" format="integer" />
    </declare-styleable>
</resources>

文件 ProgressView.java ：

public class ProgressView extends ImageView {

    public ProgressView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setAnimation(attrs);
    }

    public ProgressView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setAnimation(attrs);
    }

    public ProgressView(Context context) {
        super(context);
    }

    private void setAnimation(AttributeSet attrs) {
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ProgressView);
        int frameCount = a.getInt(R.styleable.ProgressView_frameCount, 12);  
        int duration = a.getInt(R.styleable.ProgressView_duration, 1000);
        a.recycle();

        setAnimation(frameCount, duration);
    }

    public void setAnimation(final int frameCount, final int duration) {
        Animation a = AnimationUtils.loadAnimation(getContext(), R.anim.progress_anim);
        a.setDuration(duration);
        a.setInterpolator(new Interpolator() {

            @Override
            public float getInterpolation(float input) {
                return (float)Math.floor(input*frameCount)/frameCount;
            }
        });
        startAnimation(a);
    }
}

文件 activity_main.xml ：

<com.example.widget.ProgressView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_progress" 
    app:frameCount="8"
    app:duration="1000"/>

文件 RES /动画/ progress_anim.xml ：上面

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