英文:
App crashes when using TransitionDrawable
问题
以下是翻译的内容：
我想在按钮被点击时使背景颜色过渡变化，但是一旦我按下按钮，我的应用似乎会崩溃。按钮运行TransitionDrawable代码。我已将背景设置为包含transition的drawable文件夹。有人可以帮助我吗？非常感谢！
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void colourChangeButton(View view) {
final TransitionDrawable transition = (TransitionDrawable) view.getBackground();
transition.startTransition(1000);
}
}
这是定义颜色的我的可绘制文件：
第一个文件（blue_background.xml）：
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<color android:color="#2575fc"></color>
</item>
</selector>
第二个文件（pink_background.xml）：
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<color android:color="#ff0844"></color>
</item>
</selector>
这是我的过渡可绘制文件（transition.xml）：
<?xml version="1.0" encoding="utf-8"?>
<transition xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/blue_background"></item>
<item android:drawable="@drawable/pink_background"></item>
</transition>
英文:
I want to transition the color of my background when a button is clicked but my app seems to crash once I press the button. The button runs the TransitionDrawable code. I have set my background to the drawable folder containing the transition.Could anyone help me? Thank you very much!
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void colourChangeButton(View view) {
final TransitionDrawable transition = (TransitionDrawable) view.getBackground();
transition.startTransition(1000);
}
}
Here are my drawable files that define the colours:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<color android:color="#2575fc"></color>
</item>
</selector>
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<color android:color="#ff0844"></color>
</item>
</selector>
Here is my transition drawable file :
<?xml version="1.0" encoding="utf-8"?>
<transition xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/blue_background"></item>
<item android:drawable="@drawable/pink_background"></item>
</transition>
答案1
得分: 1
你离成功不远了！
你需要将过渡可绘制对象设置为视图的背景。
假设你的活动布局 XML 名称为 activity_main.xml，你的过渡可绘制文件名为 transition.xml。
在你的 activity_main.xml 的根布局中：
<LinearLayout
...
android:id="@+id/main_layout"
android:background="@drawable/transition">
<Button
android:id="@+id/start_transition_button"
... />
...
在 MainActivity.java 中：
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
TransitionDrawable transition = (TransitionDrawable) layout.getBackground();
Button button = (Button) findViewById(R.id.start_transition_button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
transition.startTransition(500);
}
});
}
}
以下是一篇关于此的优质文章：
https://proandroiddev.com/transitiondrawable-small-gems-of-the-android-framework-4dcdd3c83319
英文:
You are almost there!
You need to set the transition drawable as the background of your view.
Let's say your activity's layout xml is called activity_main.xml and your
transition drawable file is called transition.xml.
In the root layout of your activity_main.xml:
<LinearLayout
...
id="@+id/main_layout"
background="@drawable/transition">
<Button
id="@+id/start_transition_button"
... />
...
In MainActivity.java:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
TransitionDrawable transition = (TransitionDrawable) layout.getBackground();
Button button = (Button) findViewById(R.id.start_transition_button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
transition.startTransition(500);
}
}
}
}
Here is a good post about it:
https://proandroiddev.com/transitiondrawable-small-gems-of-the-android-framework-4dcdd3c83319
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