本文实例讲述了Android编程实现图片背景渐变切换与图层叠加效果。分享给大家供大家参考,具体如下:
本例要实现的目的:
1。图片背景渐变的切换,例如渐变的从红色切换成绿色。
2。代码中进行图层叠加,即把多个可拉的叠加在一起显示在一个组件之上。
效果图:
代码很简单:
(1)布局文件:
& lt; RelativeLayout xmlns: android=" http://schemas.android.com/apk/res/android "
xmlns:工具=" http://schemas.android.com/tools "
android: layout_width=" match_parent "
android: layout_height=" match_parent "
android: paddingLeft=" @dimen/activity_horizontal_margin”
android: paddingRight=" @dimen/activity_horizontal_margin”
android: paddingTop=" @dimen/activity_vertical_margin”
android: paddingBottom=" @dimen/activity_vertical_margin”
工具:忽视=" ContentDescription "
工具:上下文=?MainActivity”比;
& lt; ImageView
android: id=癅 + id/color_iv”
android: layout_width=" 200 dp”
android: layout_height=" 200 dp”
android: layout_centerHorizontal=" true "
android: src=" https://www.yisu.com/zixun/@drawable image_bg_2 "
android: layout_margin=" 20 dp/比;
& lt; TextView
android: id=癅 + id/note_text”
android: layout_below=癅 + id/color_iv”
android: layout_width=" wrap_content "
android: layout_height=" wrap_content "
android: textSize=" 16 sp "
android: layout_margin=" 10 dp”
android:文本="点击颜色块,切换图片背景”/比;
LinearLayout & lt;
android: layout_width=" match_parent "
android: layout_height=48“斜坡”,
android: layout_below=癅 + id/note_text”
android: layout_marginBottom=" 8下降”
android: layout_marginLeft=" 4下降”
android: layout_marginRight=" 4下降”
面向android:="水平"比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 99666666 "
android: onClick=" onColorClicked "
android:标签=" # 99666666 "/比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 9996 aa39 "
android: onClick=" onColorClicked "
android:标签=" # 9996 aa39 "/比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 99 c74b46 "
android: onClick=" onColorClicked "
android:标签=" # 99 c74b46 "/比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 99 f4842d "
android: onClick=" onColorClicked "
android:标签=" # 99 f4842d "/比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 993 f9fe0 "
android: onClick=" onColorClicked "
android:标签=" # 993 f9fe0 "/比;
& lt; ImageView
android: layout_width=" 0下降”
android: layout_height=" match_parent "
android: layout_margin=" 4下降”
android: layout_weight=" 1 "
android:背景=" # 995161 bc”
android: onClick=" onColorClicked "
android:标签=" # 995161 bc”/比;
& lt;/LinearLayout>
& lt;/RelativeLayout>
之前
(2)活动代码:
包com.sinatj.colorgradientanim;
进口android.graphics.Color;
进口android.graphics.drawable.ColorDrawable;
进口android.graphics.drawable.Drawable;
进口android.graphics.drawable.LayerDrawable;
进口android.graphics.drawable.TransitionDrawable;
进口android.os.Build;
进口handler;
进口android.support.v7.app.ActionBarActivity;
进口android.os.Bundle;
进口android.view.View;
进口android.widget.ImageView;
公开课MainActivity延伸ActionBarActivity {
私人ImageView ImageView;
私人可拉的oldBackground=零;
私人可拉的bgDrawable;
@Override
保护无效onCreate(包savedInstanceState) {
super.onCreate (savedInstanceState);
setContentView (R.layout.activity_main);
imageView=(imageView) findViewById (R.id.color_iv);
bgDrawable=getresource () .getDrawable (R.drawable.image_bg_1);//初始颜色
changeColor (Color.parseColor (" # 6696 aa39 "));
}
私人空间changeColor (int newColor) {
可拉的colorDrawable=new colorDrawable (newColor);//图层叠加
LayerDrawable ld=new LayerDrawable(新可拉的[]{bgDrawable, colorDrawable});
如果(oldBackground==null) {
imageView.setBackgroundDrawable (ld);
其他}{//渐变切换
TransitionDrawable td=new TransitionDrawable(新可拉的[]{oldBackground, ld});
imageView.setBackgroundDrawable (td);
td.startTransition (300);
}
oldBackground=ld;
}
公共空间onColorClicked(查看v) {
.toString int颜色=Color.parseColor (v.getTag () ());
changeColor(颜色);
}
}
