我正在制作录音应用程序。在录制期间我使用可视化工具像普通录音应用程序一样。但是在特定时间想要在画布上绘制可绘制的可视化工具(即自定义类扩展View类) )。
像这个白色的可绘制点。
这是我的自定义视图类。
public class VisualizerView extends View {
private static final int LINE_WIDTH = 1; // width of visualizer lines
private static final int LINE_SCALE = 75; // scales visualizer lines
private List<VisuallizerItem> visuallizerItems; // amplitudes for line lengths
private int width; // width of this View
private int height; // height of this View
private Paint linePaint; // specifies line drawing characteristics
//Boolean isImage=false;
// constructor
public VisualizerView(Context context, AttributeSet attrs) {
super(context, attrs); // call superclass constructor
linePaint = new Paint(); // create Paint for lines
linePaint.setColor(getResources().getColor(R.color.visualizerColor)); // set color to green
linePaint.setStrokeWidth(LINE_WIDTH); // set stroke width
}
// called when the dimensions of the View change
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
width = w; // new width of this View
height = h; // new height of this View
visuallizerItems = new ArrayList<VisuallizerItem>();
}
// clear all amplitudes to prepare for a new visualization
public void clear() {
visuallizerItems.clear();
}
// add the given amplitude to the amplitudes ArrayList
public void addAmplitude(VisuallizerItem visuallizerItem) {
// isImage=false;
visuallizerItems.add(visuallizerItem); // add newest to the amplitudes ArrayList
// if the power lines completely fill the VisualizerView
if (visuallizerItems.size() * LINE_WIDTH >= width) {
visuallizerItems.remove(0); // remove oldest power value
}
}
public void addAmplitudeImage(VisuallizerItem visuallizerItem) {
//isImage=true;
visuallizerItems.add(visuallizerItem); // add newest to the amplitudes ArrayList
// if the power lines completely fill the VisualizerView
if (visuallizerItems.size() * LINE_WIDTH >= width) {
visuallizerItems.remove(0); // remove oldest power value
}
}
// draw the visualizer with scaled lines representing the amplitudes
@Override
public void onDraw(Canvas canvas) {
int middle = height / 2; // get the middle of the View
float curX = 0; // start curX at zero
// for each item in the amplitudes ArrayList
for (VisuallizerItem power : visuallizerItems) {
if (power.isImage == -100) {
float scaledHeight = power.amplitude / LINE_SCALE; // scale the power
curX += LINE_WIDTH; // increase X by LINE_WIDTH
// draw a line representing this item in the amplitudes ArrayList
canvas.drawLine(curX, middle + scaledHeight / 2, curX, middle
- scaledHeight / 2, linePaint);
} else {//**Here i'm trying to draw mark on canvas**
power.isImage = -100;
//TODO draw attachment image here
Paint p = new Paint();
Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.yellow);
p.setColor(Color.RED);
canvas.drawBitmap(b, visuallizerItems.size(), middle, p);
}
}
}
}
此代码添加白色标记一次,但在onDraw再次调用时将其删除。 实际上我想在画布上画一个像白点一样的标记。
不知道为什么要删除它。请帮助我
提前致谢
答案 0 :(得分:0)
如果再次调用onDraw后删除了点,是否与for循环迭代的方式有关?