Java 未知类别：'；按钮'&；无效方法脱毒；findViewById所需的返回类型
我是android新手，请原谅我的无知。我正试图在我的主要活动中添加一个按钮，单击该按钮将使应用程序转换为摄像头视图 主要活动代码： 我有一个问题，它是星号，声明 第一：（未知类：“按钮”） 第二：（无效的方法声明）用于“findViewById” 第三：（未知类R.id.按钮） activity_main.xml：Java 未知类别：'；按钮'&；无效方法脱毒；findViewById所需的返回类型,java,android,android-studio,android-button,Java,Android,Android Studio,Android Button,我是android新手，请原谅我的无知。我正试图在我的主要活动中添加一个按钮，单击该按钮将使应用程序转换为摄像头视图 主要活动代码： 我有一个问题，它是星号，声明 第一：（未知类：“按钮”） 第二：（无效的方法声明）用于“findViewById” 第三：（未知类R.id.按钮） activity_main.xml： 我以前的问题解决了，解决了问题后，更新了代码 package com.cerezaenterprises.swiftversionuno; import android.
package com.cerezaenterprises.swiftversionuno;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, CameraView1.class);
startActivity(intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
super.onOptionsItemSelected(item);
return true;
}
}
package com.cerezaenterprises.swiftversionuno;
import java.io.IOException;
import java.util.List;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import static java.lang.System.loadLibrary;
/**
* Extention of SurfaceView which starts a camera preview and decode video
* content on the native side.
*/
public class CameraView1 extends SurfaceView implements SurfaceHolder.Callback,
Camera.PreviewCallback {
private static final String TAG = "LiveCamera";
static {
loadLibrary("LiveCamera");
}
public native void decode(Bitmap pTarget, byte[] pSource);
private Camera mCamera;
private byte[] mVideoSource;
private Bitmap mBackBuffer;
private Paint mPaint;
public CameraView1(Context context) {
super(context);
// Registers current class so that it listens to surface
// event (creation, destruction and changes).
getHolder().addCallback(this);
// Clears the flag keeping the surface from getting drawn.
// Necessary when not drawing from a thread.
setWillNotDraw(false);
}
public void surfaceCreated(SurfaceHolder holder) {
try {
// Acquires the default camera.
mCamera = Camera.open();
// Sets landscape mode to avoid complications related to
// screen orientation handling.
mCamera.setDisplayOrientation(0);
// Registers callbacks. Automatic preview is deactivated
// as we want to process data ourself (in a buffer).
mCamera.setPreviewDisplay(null);
mCamera.setPreviewCallbackWithBuffer(this);
} catch (IOException eIOException) {
mCamera.release();
mCamera = null;
throw new IllegalStateException();
}
}
public void surfaceChanged(SurfaceHolder pHolder, int pFormat, int pWidth,
int pHeight) {
mCamera.stopPreview();
// Finds a suitable resolution.
Size lSize = findBestResolution(pWidth, pHeight);
// Prepares video source and back buffers.
PixelFormat lPixelFormat = new PixelFormat();
PixelFormat.getPixelFormatInfo(mCamera.getParameters()
.getPreviewFormat(), lPixelFormat);
int lSourceSize = lSize.width * lSize.height
* lPixelFormat.bitsPerPixel / 8;
mVideoSource = new byte[lSourceSize];
mBackBuffer = Bitmap.createBitmap(lSize.width, lSize.height,
Bitmap.Config.ARGB_8888);
// Set-up camera size and video format. YCbCr_420_SP
// should be the default on Android anyway.
Camera.Parameters lParameters = mCamera.getParameters();
lParameters.setPreviewSize(lSize.width, lSize.height);
lParameters.setPreviewFormat(PixelFormat.YCbCr_420_SP);
mCamera.setParameters(lParameters);
// Starts receiving pictures from the camera.
mCamera.addCallbackBuffer(mVideoSource);
mCamera.startPreview();
}
private Size findBestResolution(int pWidth, int pHeight) {
List<Size> lSizes = mCamera.getParameters().getSupportedPreviewSizes();
// Finds the biggest resolution which fits the screen.
// Else, returns the first resolution found.
Size lSelectedSize = mCamera.new Size(0, 0);
for (Size lSize : lSizes) {
if ((lSize.width <= pWidth) && (lSize.height <= pHeight)
&& (lSize.width >= lSelectedSize.width)
&& (lSize.height >= lSelectedSize.height)) {
lSelectedSize = lSize;
}
}
// Previous code assume that there is a preview size smaller
// than screen size. If not, hopefully the Android API
// guarantees that at least one preview size is available.
if ((lSelectedSize.width == 0) || (lSelectedSize.height == 0)) {
lSelectedSize = lSizes.get(0);
}
Log.d(TAG, "findBestResolution: " + lSelectedSize.width + ","
+ lSelectedSize.height);
return lSelectedSize;
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Releases camera which is a shared resource.
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
// These variables can take a lot of memory. Gets rid of
// them as fast as we can.
mCamera = null;
mVideoSource = null;
mBackBuffer = null;
}
}
public void onPreviewFrame(byte[] pData, Camera pCamera) {
// New data has been received from camera. Processes it and
// requests surface to be redrawn right after.
decode(mBackBuffer, pData);
invalidate();
}
@Override
protected void onDraw(Canvas pCanvas) {
if (mCamera != null) {
// Draws resulting image at screen origin.
pCanvas.drawBitmap(mBackBuffer, 0, 0, mPaint);
// Enqueues buffer again to get next image.
mCamera.addCallbackBuffer(mVideoSource);
}
}
}
package com.cerezaenterprises.swiftVersionNo；
导入java.io.IOException；
导入java.util.List；
导入android.content.Context；
导入android.graphics.Bitmap；
导入android.graphics.Canvas；
导入android.graphics.Paint；
导入android.graphics.PixelFormat；
导入android.hardware.Camera；
导入android.hardware.Camera.Size；
导入android.util.Log；
导入android.view.SurfaceHolder；
导入android.view.SurfaceView；
导入静态java.lang.System.loadLibrary；
/**
*SurfaceView的扩展，用于启动摄像头预览和解码视频
*本机端的内容。
*/
公共类CameraView1扩展了SurfaceView实现了SurfaceHolder.Callback，
摄影机。预览回调{
私有静态最终字符串标记=“LiveCamera”；
静止的{
loadLibrary（“LiveCamera”）；
}
公共本机void解码（位图pTarget，字节[]pSource）；
私人摄像机麦卡梅拉；
专用字节[]mVideoSource；
专用位图缓冲区；
私人油漆；
公共摄像W1（背景）{
超级（上下文）；
//注册当前类，以便它侦听曲面
//事件（创建、销毁和更改）。
getHolder（）.addCallback（此）；
//清除阻止绘制曲面的标志。
//非从螺纹上拔出时必须使用。
setWillNotDraw（假）；
}
已创建的公共空白表面（表面持有人）{
试一试{
//获取默认摄影机。
mCamera=Camera.open（）；
//设置横向模式以避免与
//屏幕方向处理。
mCamera.setDisplayOrientation（0）；
//注册回调。自动预览已停用
//因为我们希望自己（在缓冲区中）处理数据。
mCamera.setPreviewDisplay（空）；
mCamera.setPreviewCallbackWithBuffer（此）；
}捕获（IOException eIOException）{
mCamera.release（）；
mCamera=null；
抛出新的非法状态异常（）；
}
}
公共空隙表面改变（表面厚壁、内部形状、内部宽度、，
内特（菲特）{
mCamera.stopPreview（）；
//找到合适的解决方案。
尺寸lSize=最终解决方案（pWidth，pHeight）；
//准备视频源和后台缓冲区。
PixelFormat lPixelFormat=新的PixelFormat（）；
PixelFormat.getPixelFormatInfo（mCamera.getParameters（）
.getPreviewFormat（），lPixelFormat）；
int lSourceSize=lSize.width*lSize.height
*lPixelFormat.bitsPerPixel/8；
mVideoSource=新字节[lSourceSize]；
mBackBuffer=Bitmap.createBitmap（lSize.width、lSize.height、，
位图.Config.ARGB_8888）；
//设置摄像机尺寸和视频格式。YCbCr_420_SP
//应该是Android上的默认设置。
Camera.Parameters lParameters=mCamera.getParameters（）；
lParameters.setPreviewSize（lSize.width，lSize.height）；
lParameters.setPreviewFormat（PixelFormat.YCbCr_420_SP）；
设置参数（lParameters）；
//开始从相机接收图片。
mCamera.addCallbackBuffer（mVideoSource）；
mCamera.startPreview（）；
}
私有大小的findBestResolution（整数宽，整数宽）{
List lSizes=mCamera.getParameters（）.getSupportedPreviewSizes（）；
//查找适合屏幕的最大分辨率。
//否则，返回找到的第一个分辨率。
Size lSelectedSize=mCamera.new Size（0,0）；
用于（大小：lSizes:lSizes）{
如果（（lSize.width=lSelectedSize.height））{
lSelectedSize=lSize；
}
}
//以前的代码假设预览大小较小
//如果不是，希望是Android API
//保证至少有一个预览大小可用。
如果（（lSelectedSize.width==0）| |（lSelectedSize.height==0））{
lSelectedSize=lSizes.get（0）；
}
Log.d（标记“findBestResolution:+lSelectedSize.width+”，“
+l所选尺寸、高度）；
返回lSelectedSize；
}
公共空间表面覆盖（表面覆盖物持有人）{
//释放作为共享资源的摄影机。
if（mCamera！=null）{
mCamera.stopPreview（）；
mCamera.release（）；
//这些变量可能会占用大量内存
//我们尽可能快地找到他们。
mCamera=null；
mVideoSource=null；
mBackBuffer=null；
}
}
预览帧上的公共无效（字节[]pData，摄像头pCamera）{
//已从摄像机接收到新数据。对其进行处理并
//请求立即重新绘制曲面。
解码（mBackBuffer，pData）；
使无效（）；
}
@凌驾
受保护的void onDraw（帆布pCanvas）{
if（mCamera！=null）{
//在屏幕原点绘制结果图像。
pCanvas.drawBitmap（mBackBuffer，0，0，mPaint）；
//再次将缓冲区排队以获取下一个图像。
麦卡梅拉。
package com.cerezaenterprises.swiftversionuno;
import java.io.IOException;
import java.util.List;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import static java.lang.System.loadLibrary;
/**
* Extention of SurfaceView which starts a camera preview and decode video
* content on the native side.
*/
public class CameraView1 extends SurfaceView implements SurfaceHolder.Callback,
Camera.PreviewCallback {
private static final String TAG = "LiveCamera";
static {
loadLibrary("LiveCamera");
}
public native void decode(Bitmap pTarget, byte[] pSource);
private Camera mCamera;
private byte[] mVideoSource;
private Bitmap mBackBuffer;
private Paint mPaint;
public CameraView1(Context context) {
super(context);
// Registers current class so that it listens to surface
// event (creation, destruction and changes).
getHolder().addCallback(this);
// Clears the flag keeping the surface from getting drawn.
// Necessary when not drawing from a thread.
setWillNotDraw(false);
}
public void surfaceCreated(SurfaceHolder holder) {
try {
// Acquires the default camera.
mCamera = Camera.open();
// Sets landscape mode to avoid complications related to
// screen orientation handling.
mCamera.setDisplayOrientation(0);
// Registers callbacks. Automatic preview is deactivated
// as we want to process data ourself (in a buffer).
mCamera.setPreviewDisplay(null);
mCamera.setPreviewCallbackWithBuffer(this);
} catch (IOException eIOException) {
mCamera.release();
mCamera = null;
throw new IllegalStateException();
}
}
public void surfaceChanged(SurfaceHolder pHolder, int pFormat, int pWidth,
int pHeight) {
mCamera.stopPreview();
// Finds a suitable resolution.
Size lSize = findBestResolution(pWidth, pHeight);
// Prepares video source and back buffers.
PixelFormat lPixelFormat = new PixelFormat();
PixelFormat.getPixelFormatInfo(mCamera.getParameters()
.getPreviewFormat(), lPixelFormat);
int lSourceSize = lSize.width * lSize.height
* lPixelFormat.bitsPerPixel / 8;
mVideoSource = new byte[lSourceSize];
mBackBuffer = Bitmap.createBitmap(lSize.width, lSize.height,
Bitmap.Config.ARGB_8888);
// Set-up camera size and video format. YCbCr_420_SP
// should be the default on Android anyway.
Camera.Parameters lParameters = mCamera.getParameters();
lParameters.setPreviewSize(lSize.width, lSize.height);
lParameters.setPreviewFormat(PixelFormat.YCbCr_420_SP);
mCamera.setParameters(lParameters);
// Starts receiving pictures from the camera.
mCamera.addCallbackBuffer(mVideoSource);
mCamera.startPreview();
}
private Size findBestResolution(int pWidth, int pHeight) {
List<Size> lSizes = mCamera.getParameters().getSupportedPreviewSizes();
// Finds the biggest resolution which fits the screen.
// Else, returns the first resolution found.
Size lSelectedSize = mCamera.new Size(0, 0);
for (Size lSize : lSizes) {
if ((lSize.width <= pWidth) && (lSize.height <= pHeight)
&& (lSize.width >= lSelectedSize.width)
&& (lSize.height >= lSelectedSize.height)) {
lSelectedSize = lSize;
}
}
// Previous code assume that there is a preview size smaller
// than screen size. If not, hopefully the Android API
// guarantees that at least one preview size is available.
if ((lSelectedSize.width == 0) || (lSelectedSize.height == 0)) {
lSelectedSize = lSizes.get(0);
}
Log.d(TAG, "findBestResolution: " + lSelectedSize.width + ","
+ lSelectedSize.height);
return lSelectedSize;
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Releases camera which is a shared resource.
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
// These variables can take a lot of memory. Gets rid of
// them as fast as we can.
mCamera = null;
mVideoSource = null;
mBackBuffer = null;
}
}
public void onPreviewFrame(byte[] pData, Camera pCamera) {
// New data has been received from camera. Processes it and
// requests surface to be redrawn right after.
decode(mBackBuffer, pData);
invalidate();
}
@Override
protected void onDraw(Canvas pCanvas) {
if (mCamera != null) {
// Draws resulting image at screen origin.
pCanvas.drawBitmap(mBackBuffer, 0, 0, mPaint);
// Enqueues buffer again to get next image.
mCamera.addCallbackBuffer(mVideoSource);
}
}
}
--------- beginning of crash
07-29 11:33:36.336 2074-2074/com.cerezaenterprises.swiftversionuno E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.cerezaenterprises.swiftversionuno, PID: 2074
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.cerezaenterprises.swiftversionuno/com.cerezaenterprises.swiftversionuno.CameraView1}: java.lang.InstantiationException: class com.cerezaenterprises.swiftversionuno.CameraView1 has no zero argument constructor
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.InstantiationException: class com.cerezaenterprises.swiftversionuno.CameraView1 has no zero argument constructor
at java.lang.Class.newInstance(Class.java:1597)
at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.NoSuchMethodException: <init> []
at java.lang.Class.getConstructor(Class.java:531)
at java.lang.Class.getDeclaredConstructor(Class.java:510)
at java.lang.Class.newInstance(Class.java:1595)
at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
package com.cerezaenterprises.swiftversionuno;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, CameraView1.class);
startActivity(intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
super.onOptionsItemSelected(item);
return true;
}
}