在两个活动之间切换时，屏幕在从右到左之间滑动。当我按返回键时，屏幕从右向左滑动。当我从活动中按后退键以更改屏幕滑动方向时，这是一种方式吗？
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2 回答
5
对的，这是可能的。捕获后退键事件或任何其他导致新屏幕加载的事件后，您可以控制屏幕滑动的方向，但如何做到这一点并不直观。布局的最外层永远不会被您的代码动画化，因此您可能需要将布局放置在包装器中。您还必须从您希望动画发生的屏幕的 onCreate() 内部调用动画代码。
如果您使用“android.example”作为包为自己创建一个名为“ScreenTransitionLab”的项目，您可以使用以下示例来帮助您了解如何完成您想要做的事情。它目前设置为顶部和底部过渡，但可以轻松修改为使用左右过渡。
修改后的主屏幕，因此整个屏幕将滑动：
<?xml version="1.0" encoding="utf-8"?>
<!--
Wrapper layout whose children are to be animated. The outermost layout
used by an activity can never be animated, so this wrapper is needed.
The wrapper layout is given a different color so it can be
distinguished from the layout that is animated.
-->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#0000FF"
>
<!-- Actual layout that is animated. -->
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF0000"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/btnForwards"
android:text="Forwards" />
</LinearLayout>
</LinearLayout>
修改后的新屏幕，使整个屏幕将滑动：
<?xml version="1.0" encoding="utf-8"?>
<!--
Wrapper layout whose children are to be animated. The outermost layout
used by an activity can never be animated, so this wrapper is needed.
The wrapper layout is given a different color so it can be
distinguished from the layout that is animated.
-->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#0000FF"
>
<!-- Actual layout that is animated. -->
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF0000"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/btnForwards"
android:text="Forwards" />
</LinearLayout>
</LinearLayout>
在 NewScreen 活动中单击“向后”按钮时动画的 ScreenTransitionsLab 活动：
package android.example;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
public class ScreenTransitionLab extends Activity {
// Layout fields
protected LinearLayout mainLayout;
public static Button btnForwards = null;
public static Activity currentActivity;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
currentActivity = this;
/*
* This creates View objects from the xml file. The xml file should
* define all views and all static attributes.
*/
mainLayout = (LinearLayout) getLayoutInflater().inflate(R.layout.main,
null);
btnForwards = (Button) mainLayout.findViewById(R.id.btnForwards);
btnForwards.setOnClickListener(forwardsOnClickListener);
UIHelper.setSlideDirection(mainLayout, UIHelper.bottom);
/*
* Use the Layout that contains the View objects that were modified to
* create screen that will be shown after activity is done processing
* instead of the xml file. The Layout will contain all of the views and
* static attributes that were defined in the xml file plus all of the
* dynamic attributes that were defined in the code above.
*/
setContentView(mainLayout);
}
public View.OnClickListener forwardsOnClickListener = new View.OnClickListener() {
public void onClick(View v) {
Activity currentActivity = (Activity) v.getContext();
Intent i = new Intent(currentActivity, NewScreen.class);
currentActivity.startActivity(i);
/*
* Remove activity that is no longer current from the activity stack
* to prevent the application from bloating.
*/
currentActivity.finish();
}
};
}
在 ScreenTransitionsLab 活动中单击“转发”按钮时动画的 NewScreen 活动：
package android.example;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
public class NewScreen extends Activity {
protected LinearLayout mainLayout;
public static Button btnBackwards = null;
public static Activity currentActivity;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
currentActivity = this;
/*
* This creates View objects from the xml file. The xml file should
* define all views and all static attributes.
*/
mainLayout = (LinearLayout) getLayoutInflater().inflate(
R.layout.new_screen, null);
btnBackwards = (Button) mainLayout.findViewById(R.id.btnBackwards);
btnBackwards.setOnClickListener(backwardsOnClickListener);
UIHelper.setSlideDirection(mainLayout, UIHelper.top);
/*
* Use the Layout that contains the View objects that were modified to
* create screen that will be shown after activity is done processing
* instead of the xml file. The Layout will contain all of the views and
* static attributes that were defined in the xml file plus all of the
* dynamic attributes that were defined in the code above.
*/
setContentView(mainLayout);
}
public View.OnClickListener backwardsOnClickListener = new View.OnClickListener() {
public void onClick(View v) {
Activity currentActivity = (Activity) v.getContext();
Intent i = new Intent(currentActivity, ScreenTransitionLab.class);
currentActivity.startActivity(i);
/*
* Remove activity that is no longer current from the activity stack
* to prevent the application from bloating.
*/
currentActivity.finish();
}
};
}
实际执行动画的 UIHelper 类：
package android.example;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.LayoutAnimationController;
import android.view.animation.TranslateAnimation;
public class UIHelper {
public static final int top = 1;
public static final int bottom = 2;
public static final int left = 3;
public static final int right = 4;
/**
* Set direction that children in the panel will slide in from when next
* displayed.
*
* @param panel
* {@link ViewGroup} whose children will be slid in from the
* specified direction when the panel is next displayed.
* @param fromDirection
* Primitive int indicating the direction to slide the children
* of the panel from.
*/
public static void setSlideDirection(ViewGroup panel, int fromDirection) {
float fromX = 0;
float toX = 0;
float fromY = 0;
float toY = 0;
AnimationSet set = new AnimationSet(true);
Animation animation = new AlphaAnimation(0.0f, 1.0f);
animation.setDuration(100);
set.addAnimation(animation);
switch (fromDirection) {
case top:
fromX = 0.00f;
toX = 0.00f;
fromY = -1.00f;
toY = 0.00f;
break;
case bottom:
fromX = 0.00f;
toX = 0.00f;
fromY = 1.00f;
toY = 0.00f;
break;
case left:
fromX = -1.00f;
toX = 0.00f;
fromY = 0.00f;
toY = 0.00f;
break;
default:
fromX = 1.00f;
toX = 0.00f;
fromY = 0.00f;
toY = 0.00f;
break;
}
animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, fromX,
Animation.RELATIVE_TO_SELF, toX, Animation.RELATIVE_TO_SELF,
fromY, Animation.RELATIVE_TO_SELF, toY);
animation.setDuration(200);
set.addAnimation(animation);
LayoutAnimationController controller = new LayoutAnimationController(
set, 0.25f);
panel.setLayoutAnimation(controller);
}
}
于 2011-03-28T19:16:15.453 回答
4
可以使 Danny 的解决方案起作用，但它过于复杂。您想了解的关键方法是 overridePendingTransition()。
这是我模拟使用它的主要活动。我让它垂直过渡只是为了表明你可以在任何你喜欢的方向上进行转换：
package com.superliminal.test;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class ScreenTransitionTest extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btnForwards = (Button) findViewById(R.id.btnForwards);
btnForwards.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Activity currentActivity = (Activity) v.getContext();
Intent i = new Intent(currentActivity, NewScreen.class);
// Tell the new activity how return when finished.
i.putExtra("anim id in", R.anim.down_in);
i.putExtra("anim id out", R.anim.down_out);
currentActivity.startActivity(i);
// This makes the new screen slide up as it fades in
// while the current screen slides up as it fades out.
overridePendingTransition(R.anim.up_in, R.anim.up_out);
}
});
}
}
这是新屏幕的实现：
package com.superliminal.test;
import android.app.Activity;
import android.os.Bundle;
public class NewScreen extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.new_screen);
}
@Override
public void onBackPressed() {
this.finish();
// Use exiting animations specified by the parent activity if given
// Translate left if not specified.
overridePendingTransition(
getIntent().getIntExtra("anim id in", R.anim.left_in),
getIntent().getIntExtra("anim id out", R.anim.left_out));
}
}
您的布局文件可以是您喜欢的任何内容。您不需要包装层。这是我的 main.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#990000" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Main Activity" />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/btnForwards"
android:text="Forward" />
</LinearLayout>
这是我的 new_screen.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#009900" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="New Screen. Use back button to return." />
</RelativeLayout>
您唯一需要的其他东西是放在 res/anim 文件夹中的动画 XML 文件。
up_in.xml：
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate android:fromYDelta="-100%p" android:toYDelta="0" android:duration="1000"/>
<alpha android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="1000" />
</set>
up_out.xml：
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate android:fromYDelta="0" android:toYDelta="100%p" android:duration="1000"/>
<alpha android:fromAlpha="1.0" android:toAlpha="0.0" android:duration="1000" />
</set>
down_in.xml：
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate android:fromYDelta="100%p" android:toYDelta="0" android:duration="1000"/>
<alpha android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="1000" />
</set>
down_out.xml：
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate android:fromYDelta="0" android:toYDelta="-100%p" android:duration="1000"/>
<alpha android:fromAlpha="1.0" android:toAlpha="0.0" android:duration="1000" />
</set>
于 2012-03-17T06:06:03.157 回答