我正在制作一个旋转像这篇文章这样的图像的例子。
我扩展了 ImageView，然后覆盖 OnDraw 并放入 MainActivity。但它触发了“InflateException”。这是我的示例代码：
MImageView
public class MImageView extends ImageView {
public MImageView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
canvas.save();
canvas.rotate(45, 0, 0);
super.onDraw(canvas);
canvas.restore();
}
}
主要活动
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MImageView mImageView = (MImageView) findViewById(R.id.imageView1);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
main_activity.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<com.example.rotatetest.MImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" />
</RelativeLayout>
显现
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.rotatetest"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.rotatetest.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
日志猫
08-16 10:21:31.820: D/AndroidRuntime(5135): Shutting down VM
08-16 10:21:31.820: W/dalvikvm(5135): threadid=1: thread exiting with uncaught exception (group=0x40ab4210)
08-16 10:21:31.820: E/AndroidRuntime(5135): FATAL EXCEPTION: main
08-16 10:21:31.820: E/AndroidRuntime(5135): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rotatetest/com.example.rotatetest.MainActivity}: android.view.InflateException: Binary XML file line #13: Error inflating class com.example.rotatetest.MImageView
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2049)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2083)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread.access$600(ActivityThread.java:134)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1233)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.os.Handler.dispatchMessage(Handler.java:99)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.os.Looper.loop(Looper.java:137)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread.main(ActivityThread.java:4697)
08-16 10:21:31.820: E/AndroidRuntime(5135): at java.lang.reflect.Method.invokeNative(Native Method)
08-16 10:21:31.820: E/AndroidRuntime(5135): at java.lang.reflect.Method.invoke(Method.java:511)
08-16 10:21:31.820: E/AndroidRuntime(5135): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
08-16 10:21:31.820: E/AndroidRuntime(5135): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
08-16 10:21:31.820: E/AndroidRuntime(5135): at dalvik.system.NativeStart.main(Native Method)
08-16 10:21:31.820: E/AndroidRuntime(5135): Caused by: android.view.InflateException: Binary XML file line #13: Error inflating class com.example.rotatetest.MImageView
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.createView(LayoutInflater.java:589)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.rInflate(LayoutInflater.java:739)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
08-16 10:21:31.820: E/AndroidRuntime(5135): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:255)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.Activity.setContentView(Activity.java:1879)
08-16 10:21:31.820: E/AndroidRuntime(5135): at com.example.rotatetest.MainActivity.onCreate(MainActivity.java:15)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.Activity.performCreate(Activity.java:4539)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2013)
08-16 10:21:31.820: E/AndroidRuntime(5135): ... 11 more
08-16 10:21:31.820: E/AndroidRuntime(5135): Caused by: java.lang.NoSuchMethodException: <init> [class android.content.Context, interface android.util.AttributeSet]
08-16 10:21:31.820: E/AndroidRuntime(5135): at java.lang.Class.getConstructorOrMethod(Class.java:460)
08-16 10:21:31.820: E/AndroidRuntime(5135): at java.lang.Class.getConstructor(Class.java:431)
08-16 10:21:31.820: E/AndroidRuntime(5135): at android.view.LayoutInflater.createView(LayoutInflater.java:561)
08-16 10:21:31.820: E/AndroidRuntime(5135): ... 22 more
我做错什么了吗？