Android利用translate、scale、alpha、rotate实现动画效果
在Android中可以用animation实现动画效果，Android中的animation由四种类型组成:
- alpha 透明度的变换
- scale 渐变尺寸伸缩动画
- translate view切换位置移动的效果
- rotate 旋转效果
这些xml我们需要定义在res/anim文件夹下面，如下图所示：
image
scale标签
- android:fromXScale="float"
Float. Starting X size offset, where 1.0 is no change. - android:toXScale="float"
Float. Ending X size offset, where 1.0 is no change. - android:fromYScale="float"
Float. Starting Y size offset, where 1.0 is no change. - android:toYScale="float"
Float. Ending Y size offset, where 1.0 is no change. - android:pivotX="float"
Float. The X coordinate to remain fixed when the object is scaled. - android:pivotY="float"
Float. The Y coordinate to remain fixed when the object is scaled.
alpha
- android:fromAlpha="float"
Float. Starting opacity offset, where 0.0 is transparent and 1.0 is opaque. - android:toAlpha="float"
Float. Ending opacity offset, where 0.0 is transparent and 1.0 is opaque.
translate
- android:fromXDelta="float"
Float or percentage. Starting X offset. Expressed either: in pixels relative to the normal position (such as "5"), in percentage relative to the element width (such as "5%"), or in percentage relative to the parent width (such as "5%p"). - android:toXDelta="float"
Float or percentage. Ending X offset. Expressed either: in pixels relative to the normal position (such as "5"), in percentage relative to the element width (such as "5%"), or in percentage relative to the parent width (such as "5%p"). - android:fromYDelta="float"
Float or percentage. Starting Y offset. Expressed either: in pixels relative to the normal position (such as "5"), in percentage relative to the element height (such as "5%"), or in percentage relative to the parent height (such as "5%p"). - android:toYDelta="float"
Float or percentage. Ending Y offset. Expressed either: in pixels relative to the normal position (such as "5"), in percentage relative to the element height (such as "5%"), or in percentage relative to the parent height (such as "5%p").
rotate
- android:fromDegrees="float"
Float. Starting angular position, in degrees - android:toDegrees="float"
Float. Ending angular position, in degrees. - android:pivotX="float
Float or percentage. The X coordinate of the center of rotation. Expressed either: in pixels relative to the object's left edge (such as "5"), in percentage relative to the object's left edge (such as "5%"), or in percentage relative to the parent container's left edge (such as "5%p"). - android:pivotY="float"
Float or percentage. The Y coordinate of the center of rotation. Expressed either: in pixels relative to the object's top edge (such as "5"), in percentage relative to the object's top edge (such as "5%"), or in percentage relative to the parent container's top edge (such as "5%p").
Animation类具有的xml属性
- android:detachWallpaper
Special option for window animations: if this window is on top of a wallpaper, don't animate the wallpaper with it. - android:duration
Amount of time (in milliseconds) for the animation to run. - android:fillAfter
When set to true, the animation transformation is applied after the animation is over. - android:fillBefore
When set to true or when fillEnabled is not set to true, the animation transformation is applied before the animation has started.
android:fillEnabled When set to true, the value of fillBefore is taken into account. - android:interpolator
Defines the interpolator used to smooth the animation movement in time. - android:repeatCount
Defines how many times the animation should repeat. - android:repeatMode
Defines the animation behavior when it reaches the end and the repeat count is greater than 0 or infinite. - android:startOffset
Delay in milliseconds before the animation runs, once start time is reached. - android:zAdjustment
Allows for an adjustment of the Z ordering of the content being animated for the duration of the animation.
具体实例
具体实例:
alpha.xml
<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:fromAlpha="1.0"
android:toAlpha="0.1"
android:duration="3000"
android:fillBefore="true">
</alpha>
rotate.xml
<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="0"
android:toDegrees="-650"
android:pivotX="50%"
android:pivotY="50%"
android:duration="3000"
android:fillAfter="true">
</rotate>
scale.xml
<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXScale="0.0"
android:toXScale="1.4"
android:fromYScale="0.0"
android:toYScale="1.4"
android:pivotX="50%"
android:pivotY="50%"
android:duration="700" />
translate.xml
<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXDelta="0"
android:toXDelta="-80"
android:fromYDelta="0"
android:toYDelta="-80"
android:duration="2000"
android:fillBefore="true">
</translate>
set_anim.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="3000"
android:fillAfter="true">
<alpha
android:fromAlpha="0.0"
android:toAlpha="1.0" />
<scale
android:fromXScale="0.0"
android:fromYScale="0.0"
android:pivotX="50%"
android:pivotY="50%"
android:toXScale="1.4"
android:toYScale="1.4" />
<rotate
android:fromDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="720" />
</set>
java代码:
package com.qf58.learncustomview;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.text_view);
final Animation scaleAnimation = AnimationUtils.loadAnimation(this, R.anim.scale);
final Animation alphaAnimation = AnimationUtils.loadAnimation(this, R.anim.alpha);
final Animation translate = AnimationUtils.loadAnimation(this, R.anim.translate);
final Animation rotate = AnimationUtils.loadAnimation(this, R.anim.rotate);
final Animation set = AnimationUtils.loadAnimation(this,R.anim.set_anim);
findViewById(R.id.alpha).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
textView.startAnimation(alphaAnimation);
}
});
findViewById(R.id.scale).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
textView.startAnimation(scaleAnimation);
}
});
findViewById(R.id.translate).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
textView.startAnimation(translate);
}
});
findViewById(R.id.rotate).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
textView.startAnimation(rotate);
}
});
findViewById(R.id.set).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
textView.startAnimation(set);
}
});
}
}
