Android 相机预览与文本视图

Question

我的 Android 应用程序上有相机预览，但是当我向 xml 中的 TextView 添加“id”时，该应用程序不再运行。你不允许有一个带id的textview吗？我需要这个，因为我希望在进行相机预览时更改屏幕上的文本？

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"  
android:layout_width="fill_parent"  
android:layout_height="fill_parent"
 > 
<SurfaceView   android:id="@+id/camerapreview"  
android:layout_width="fill_parent"  
android:layout_height="wrap_content"  
/> 
</LinearLayout>

control.xml

<?xml version="1.0" encoding="utf-8"?>

    <ImageView android:src="@drawable/icon" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:layout_gravity="center"
        android:paddingTop="120dp" />
    <TextView android:layout_width="wrap_content" android:id="@+id/mind" 
        android:layout_height="wrap_content" android:text="First Text"
        android:layout_gravity="center" android:paddingTop="50dp"
        android:textSize="30dp" android:textStyle="bold" android:textColor="#FFFFFF" />
    <Button android:id="@+id/takepicture" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:text="Save Image"
        android:layout_gravity="center" android:paddingTop="10dp"/>
</LinearLayout>

main.java：

package com.example.androidcamera;

import java.io.IOException;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.TextView;

public class main extends Activity implements SurfaceHolder.Callback {

Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;
LayoutInflater controlInflater = null;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

    getWindow().setFormat(PixelFormat.UNKNOWN);
    surfaceView = (SurfaceView) findViewById(R.id.camerapreview);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    controlInflater = LayoutInflater.from(getBaseContext());
    View viewControl = controlInflater.inflate(R.layout.control, null);
    LayoutParams layoutParamsControl = new LayoutParams(
            LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    this.addContentView(viewControl, layoutParamsControl);

    TextView textGenerateDesc = (TextView) findViewById(R.id.mind);
    textGenerateDesc.setText("hi");

    Button buttonTakePicture = (Button) findViewById(R.id.takepicture);
    buttonTakePicture.setOnClickListener(new Button.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            camera.takePicture(myShutterCallback,    myPictureCallback_RAW,
                    myPictureCallback_JPG);
        }
    });
}

Answer 1

正如我在 xml 中看到的，您将 textview id 指定为“textview”，在代码中您通过 R.id.mind 获取它，

您是否更改了此处的代码或其你有什么代码？

Answer 2

您刚刚错过了“LinearLayout”的起始标签，

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

其余部分是相同的

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingTop="120dp"
 />
<TextView
android:id="@+id/mind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingTop="50dp"
android:text="First Text"
android:textColor="#FFFFFF"
android:textSize="30dp"
android:textStyle="bold" />

<Button
android:id="@+id/takepicture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingTop="10dp"
android:text="Save Image" />

</LinearLayout>