我正在测试使用
我觉得这很简单。这是我的自定义视图类。
WaveForm.java
当前我正在尝试将变量
canvas.drawLine()
方法将音频频率绘制到画布中。我能够在画布中进行静态绘制。基本上,我有一个测试应用程序,其中有两个按钮“开始”和“停止”,以及一个画布,我正在尝试从FFT获得的音频频率绘制。当我点击“开始”按钮时,它使用AudioRecord
类开始录制声音,并将数据收集到缓冲区中,然后通过FFT运行缓冲区以获取频率。这还处于非常早期的阶段。现在,我只是试图弄清楚如何将这些频率值传递给我的自定义视图类的onDraw
方法。以下是相关代码,从布局开始。<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.testapp.WaveForm
android:id="@+id/waveForm1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginTop="78dp" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/button1"
android:layout_alignBottom="@+id/button1"
android:layout_alignRight="@+id/waveForm1"
android:layout_marginRight="19dp"
android:text="STOP" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/waveForm1"
android:layout_alignParentTop="true"
android:text="START" />
</RelativeLayout>
我觉得这很简单。这是我的自定义视图类。
WaveForm.java
package com.example.testapp;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
public class WaveForm extends View {
private Paint mLinePaint;
float x ;
float y;
public WaveForm(Context context, AttributeSet attrs) {
super(context, attrs);
mLinePaint = new Paint();
mLinePaint.setStyle(Paint.Style.STROKE);
mLinePaint.setARGB(255, 0, 0, 255);
mLinePaint.setAntiAlias(true);
mLinePaint.setStrokeWidth(10);
x = 0.0f;
y = 0.0f;
}
@Override
protected void onDraw(Canvas canvas) {
//Instead of 50 here i would like to pass the value obtained from the Activity class
canvas.drawLine(x, 0, y, 50, mLinePaint);
y = y + 1.0f;
x = x + 1.0f;
super.onDraw(canvas);
}
}
正如我在onDraw方法的评论中提到的,我想传递我在Activity中获得的频率值,而不是50。最后,这是我的Activity:
MainActivity.java
package com.example.testapp;
import android.app.Activity;
import android.graphics.Canvas;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder.AudioSource;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
boolean recording = false;
AudioRecord audioRecord;
double[] x;
double[] y;
double currentPoint = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final View myInstance = (View) findViewById(R.id.waveForm1);
Button start = (Button) findViewById(R.id.button1);
start.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
int sampleRateInHz=44100;
int channelConfig = AudioFormat.CHANNEL_IN_MONO;
int bufferSizeInBytes = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT);
audioRecord = new AudioRecord(AudioSource.MIC, sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT, AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT));
byte[] audioData = new byte[bufferSizeInBytes/4];
FFT myFFT = new FFT(audioData.length);
Canvas canvas = new Canvas();
recording = true;
audioRecord.startRecording();
while(recording) {
audioRecord.read(audioData,0, bufferSizeInBytes/4);
//convert to double here
for(int i=0; i<audioData.length; i++) {
x[i] = (double)audioData[i];
y[i] = 0;
}
double[] samples = myFFT.fft(x, y);
for(int i=0; i<samples.length; i++) {
currentPoint = samples[i];
myInstance.draw(canvas);
myInstance.invalidate();
}
}
}
});
Button stop = (Button) findViewById(R.id.button2);
stop.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
recording = false;
audioRecord.stop();
}
});
}
}
当前我正在尝试将变量
currentPoint
传递给onDraw
方法。非常感谢您的帮助。
final View myInstance = (View) findViewById(R.id.waveForm1);
。所以基本上它不是整个类的一个实例。所以它不会让我执行myInstance.setCurrentPoint(currentPoint)
。我能不能用不同的方式来实例化那个视图,我也更喜欢setter的想法。 - PeshalmyInstance.setTag(currentPoint);
然后在onDraw
方法中使用double currentPoint = (Double)getTag();
,看看这种方式是否可行。让我知道结果。 - ρяσѕρєя KsetTag()
和getTag()
都能正常工作。非常感谢! - Peshal