我正在尝试在自定义View中绘制一条线。在这里，我创建了一个只有一个段的简单Path，从中创建了一个PathShape，最后将其粘贴到ShapeDrawable中，目的是使用它来绘制{在Canvas内{1}}。但是，这不起作用。看看我的例子，这里。
onDraw()正如您在package com.example.test;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.PathShape;
import android.util.Log;
import android.view.View;
public class TestView extends View {
private Path mPath = null;
private Paint mPaint = null;
private PathShape mPathShape = null;
private ShapeDrawable mShapeDrawable = null;
public TestView(Context context) {
super(context);
}
private void init() {
int width = this.getWidth() / 2;
int height = this.getHeight() / 2;
Log.d("init", String.format("width: %d; height: %d", width, height));
this.mPath = new Path();
this.mPath.moveTo(0, 0);
this.mPath.lineTo(width, height);
this.mPaint = new Paint();
this.mPaint.setColor(Color.RED);
this.mPathShape = new PathShape(this.mPath, 1, 1);
this.mShapeDrawable = new ShapeDrawable(this.mPathShape);
this.mShapeDrawable.getPaint().set(this.mPaint);
this.mShapeDrawable.setBounds(0, 0, width, height);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
// Doing this here because in the constructor we don't have the width and height of the view, yet
this.init();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Log.d("onDraw", "Drawing");
// This works, but won't let me do what I'm really trying to do
canvas.drawLine(0.0f, 0.0f, this.getWidth() / 2.0f, this.getHeight() / 2.0f, this.mPaint);
// This should work, but does not
//this.mPathShape.draw(canvas, this.mPaint);
// This should work, but does not
//this.mShapeDrawable.draw(canvas);
}
}
方法中的评论中所看到的那样，既不使用onDraw()也不使用PathShape将ShapeDrawable实际绘制到Path上作品。我尝试的时候什么都没画。有谁知道为什么？
我正在测试的设备是运行Android 4.1.1。
答案 0 :(得分：12)
这有两个问题。
第一种是Paint风格。默认值为Paint.Stroke.FILL，但如果有一行则无法填充。我需要添加这个（谢谢，Romain Guy）：
this.mPaint.setStyle(Paint.Style.STROKE);
第二个问题是PathShape中的标准高度和宽度不正确。我已经阅读了the documentation，但没有正确理解。一旦我解决了第一个问题，这就变得明显了。将它设置为我的自定义视图的高度和宽度（因为我正在绘制整个视图）修复了这个问题。我还必须更改ShapeDrawable的界限才能匹配。
this.mPathShape = new PathShape(this.mPath, this.getWidth(), this.getHeight());
和
this.mShapeDrawable.setBounds(0, 0, this.getWidth(), this.getHeight());
希望将来可以帮助其他人。