使用Java的Android动画

动画是一种方法，其中以特定方式组合图像集合并进行处理，然后将它们显示为运动图像。建立动画使屏幕上的对象看起来还活着。 Android有很多工具可以帮助您相对轻松地创建动画。因此，在本文中，让我们学习使用Java创建android动画。

属性表

XML ATTRIBUTES	DESCRIPTION
android:id	Sets unique id of the view
android:duration	Used to specify the duration of the animation
android:fromDegrees	Starting angular position (in degrees)
android:toDegrees	Ending angular position (in degrees)
android:fromXScale	Starting X size offset
android:toXScale	Ending of X size offset
android:fromYScale	Starting Y size offset
android:toYScale	Ending of Y size offset
android:fromAlpha	Starting alpha value for the animation (1.0 means fully opaque and 0.0 means fully transparent)
android:toAlpha	Ending alpha value
android:fromYDelta	Change in Y coordinate to be applied at the beginning of the animation
android:toYDelta	Change in Y coordinate to be applied at the end of the animation
android:pivotX	Represents the X-axis coordinates to zoom from the starting point
android:pivotY	Represents the Y-axis coordinates to zoom from the starting point
android:interpolator	It defines the rate of change of an animation
android:startOffset	Delay occurs when an animation runs (in ms), once start time is reached

如何使用Java在Android中添加动画

步骤1：创建一个新项目

• 启动Android Studio(版本> 2.2)
• 转到文件->新建->新建项目。
• 选择清空活动，然后单击下一步
• 选择最低的SDK作为21
• 选择Java语言，然后单击完成按钮。
• 修改以下XML和Java文件。

步骤2：修改activity_main.xml文件

在XML文件中，我们在RelativeLayout内添加了ImageView，TextView和Button。

步骤3：将这些XML文件添加到anim目录

修改布局后，我们将为动画创建XML文件。因此，我们将首先创建一个文件夹名称anim 。在此文件夹中，我们将添加将用于生成动画的XML文件。为此，请右键单击app / res ，然后选择“ Android资源目录”并将其命名为动画。

Android中一些常见的动画类型是

1. 闪烁–隐藏对象0.6到1秒钟。
2. 滑动–将对象垂直或水平移动到其轴。
3. 旋转–顺时针或逆时针旋转对象。
4. 缩放–在X和Y轴上放大或缩小对象。

步骤4：修改MainActivity。Java

要在android中执行动画，我们必须调用AnimationUtils类的静态函数loadAnimation() 。我们在动画对象的实例中获得结果。创建动画对象的语法：

Animation object = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.ANIMATIONFILE);

要将以上动画应用于对象(在图像中说)，我们必须调用对象的startAnimation()方法。调用方法的语法：

ImageView image = findViewById(R.id.imageID); 

image.startAnimation(object);

动画课的方法：

Method	Description
startAnimation(object)	Starts the animation
setDuration(long duration)	Sets the duration of animation
getDuration()	Gets the duration of animation
end()	Ends the animation
cancel()	Cancels the animation

Java

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageView;
  
public class MainActivity extends AppCompatActivity {
    ImageView logo;
    Button blink, slide, rotate, zoom;
  
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
  
        // GFG logo
        logo = findViewById(R.id.imageView1);
  
        // blink button
        blink = findViewById(R.id.button1);
  
        // slide button
        slide = findViewById(R.id.button2);
  
        // rotate button
        rotate = findViewById(R.id.button3);
  
        // zoom button
        zoom = findViewById(R.id.button4);
  
        // blink button listener
        blink.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                // call a static function loadAnimation()
                // of the class AnimationUtils
                Animation object
                    = AnimationUtils
                          .loadAnimation(
                              getApplicationContext(),
  
                              // blink file is in anim folder
                              R.anim.blinks);
                // call the startAnimation method
                logo.startAnimation(object);
            }
        });
        // slide button listener
        slide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                // call a static function loadAnimation()
                // of the class AnimationUtils
                Animation object
                    = AnimationUtils
                          .loadAnimation(
  
                              getApplicationContext(),
  
                              // slide file is in anim folder
                              R.anim.slide);
  
                // call the startAnimation method
                logo.startAnimation(object);
            }
        });
  
        // rotate button listener
        rotate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                // call a static function loadAnimation()
                // of the class AnimationUtils
                Animation object
                    = AnimationUtils
                          .loadAnimation(
                              getApplicationContext(),
  
                              // rotate file is in anim folder
                              R.anim.rotate);
  
                // call the startAnimation method
                logo.startAnimation(object);
            }
        });
  
        // zoom button listener
        zoom.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                // call a static function loadAnimation()
                // of the class AnimationUtils
                Animation object
                    = AnimationUtils
                          .loadAnimation(
                              getApplicationContext(),
  
                              // zoom file is in anim folder
                              R.anim.zoom);
  
                // call the startAnimation method
                logo.startAnimation(object);
            }
        });
    }
}

输出：在模拟器上运行