最終效果圖
Android Widget 的實(shí)現(xiàn)方式中 View 是由 RemoteViews 實(shí)現(xiàn)的
* <p>{@code RemoteViews} is limited to support for the following layouts:</p>
* <p>And the following widgets:</p>
* <li>{@link android.widget.AdapterViewFlipper}</li>
* <li>{@link android.widget.FrameLayout}</li>
* <li>{@link android.widget.GridLayout}</li>
* <li>{@link android.widget.GridView}</li>
* <li>{@link android.widget.LinearLayout}</li>
* <li>{@link android.widget.ListView}</li>
* <li>{@link android.widget.RelativeLayout}</li>
* <li>{@link android.widget.StackView}</li>
* <li>{@link android.widget.ViewFlipper}</li>
* <li>{@link android.widget.AnalogClock}</li>
* <li>{@link android.widget.Button}</li>
* <li>{@link android.widget.Chronometer}</li>
* <li>{@link android.widget.ImageButton}</li>
* <li>{@link android.widget.ImageView}</li>
* <li>{@link android.widget.ProgressBar}</li>
* <li>{@link android.widget.TextClock}</li>
* <li>{@link android.widget.TextView}</li>
public class RemoteViews implements Parcelable, Filter {...}
RemoteViews 并不是一個(gè) View弧呐，它繼承自 Parcelable欧募，Android 官方支持的 View 上方的少數(shù)幾種染苛，自定義 View 明顯是不支持的
private Class<?> getParameterType() {
switch (this.type) {
case BOOLEAN:
return boolean.class;
case BYTE:
return byte.class;
case SHORT:
return short.class;
case INT:
return int.class;
case LONG:
return long.class;
case FLOAT:
return float.class;
case DOUBLE:
return double.class;
case CHAR:
return char.class;
case STRING:
return String.class;
case CHAR_SEQUENCE:
return CharSequence.class;
case URI:
return Uri.class;
case BITMAP:
return Bitmap.class;
case BUNDLE:
return Bundle.class;
case INTENT:
return Intent.class;
case COLOR_STATE_LIST:
return ColorStateList.class;
case ICON:
return Icon.class;
default:
return null;
}
它不是一個(gè) View织狐，那我們就不能使用 findViewById 方法來找到對(duì)應(yīng)的 View 來進(jìn)行操作候址。
并且 set 方法也是固定的，所支持傳入 setXXX 方法的操作參數(shù)只有上面幾種。
解決方案 : 將自定義 View 放到 AOSP (Android Open Source Project) 源代碼中運(yùn)行。
public class RemoteViews implements Parcelable, Filter {...
/* (non-Javadoc)
* Used to restrict the views which can be inflated
*
* @see android.view.LayoutInflater.Filter#onLoadClass(java.lang.Class)
*/
public boolean onLoadClass(Class clazz) {
return clazz.isAnnotationPresent(RemoteView.class);
}
...
}
@RemoteView
public class LinearLayout extends ViewGroup {...}
@RemoteView
public class Button extends TextView{
...
@android.view.RemotableViewMethod
public final void setText(@StringRes int resid) {
setText(getContext().getResources().getText(resid));
mTextSetFromXmlOrResourceId = true;
mTextId = resid;
}
...
}
@RemoteView
public class ImageView extends View {...
@android.view.RemotableViewMethod(asyncImpl="setImageResourceAsync")
public void setImageResource(@DrawableRes int resId) {
...}
...
}
@RemoteView
public class TextView extends View implements ViewTreeObserver.OnPreDrawListener {...}
在 RemoteView 支持的 View 開頭都有個(gè) @RemoteView 的注解琐旁，結(jié)合 RemoteView 繼承了 Filter，
發(fā)現(xiàn)在加載 RemoteView 的時(shí)候會(huì)去判斷這個(gè)類時(shí)候是否帶有專屬的注解猜绣。所以我們的自定義 View 要加注解才能編譯成功灰殴。
@RemoteView
public class Button extends TextView{
...
@android.view.RemotableViewMethod
public final void setText(@StringRes int resid) {
setText(getContext().getResources().getText(resid));
mTextSetFromXmlOrResourceId = true;
mTextId = resid;
}
...
@RemoteView
public class ImageView extends View {...
@android.view.RemotableViewMethod(asyncImpl="setImageResourceAsync")
public void setImageResource(@DrawableRes int resId) {
...}
...
}
public class RemoteViews implements Parcelable, Filter {
...
private MethodHandle getMethod(View view, String methodName, Class<?> paramType,
boolean async) {
...
if (!method.isAnnotationPresent(RemotableViewMethod.class)) {
throw new ActionException("view: " + klass.getName()
+ " can't use method with RemoteViews: "
+ methodName + getParameters(paramType));
}
...}
...}
在 RemoteView 支持的 View 中還發(fā)現(xiàn)在對(duì)應(yīng)的set方法中都有加上 @android.view.RemotableViewMethod 的注解，回去查看到源碼發(fā)現(xiàn)掰邢，調(diào)用方法的時(shí)候也會(huì)去判斷這個(gè)Method 是否加上了專屬注解否則無法使用,會(huì)提示以下錯(cuò)誤牺陶。
2019-02-22 14:41:08.311 2516-2516/com.android.launcher3 W/AppWidgetHostView:
Error inflating RemoteViews : android.widget.RemoteViews$ActionException:
android.widget.RemoteViews$ActionException: view: android.widget.EnergyMapView
can't use method with RemoteViews: setLevels(class android.os.Bundle)
/** @hide */
@android.view.RemotableViewMethod
public void setLevels(Bundle bundle) {
Log.i("EnergyMapView", "setBundle");
setLevels(bundle.getIntArray("xx"));
}
最后將自定義 View 代碼放到 framework 中編譯
@RemoteView
public class EnergyMapView extends View {...}
將 EnergyMapView 放到 AOSP 目錄下的 /frameworks/base/core/java/android/widget/ 路徑下,然后開啟編譯流程,最后在模擬器中運(yùn)行我們的 APP
source build/envsetup.sh
lunch aosp_x86_64-eng
make update-api
make -j16
emulator
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/demo_root"
android:orientation="vertical"
android:background="@color/color_black_10"
android:layout_width="200dp"
android:layout_height="400dp">
<EnergyMapView
android:id="@+id/demo_energy_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
編譯完成之后直接在 layout 中引用即可，即便Android Studio 中沒有這個(gè)類的源碼辣之，也不會(huì)報(bào)錯(cuò)放心
remoteViews.setBundle(R.id.demo_energy_view, "setLevels", bundle);
最后直接調(diào)用即可
以上的前提是你們公司的設(shè)備的 framework 開發(fā)是自己人ｊ臁！怀估！如果不是的話建議將自定義 View 轉(zhuǎn)換成 bitmap 放到 imageView 中狮鸭。
