如何使用等borderWidth = 3和borderColor = black绘制空矩形,矩形内的部分没有内容或颜色。使用 Canvas 中的哪个函数
void drawRect(float left, float top, float right, float bottom, Paint paint)
void drawRect(RectF rect, Paint paint)
void drawRect(Rect r, Paint paint)
谢谢。
我试试这个例子
Paint myPaint = new Paint();
myPaint.setColor(Color.rgb(0, 0, 0));
myPaint.setStrokeWidth(10);
c.drawRect(100, 100, 200, 200, myPaint);
它绘制矩形并用黑色填充它,但我只想像这个图像一样“框架”:
https://i.stack.imgur.com/2aUXE.png
试试paint.setStyle(Paint.Style.STROKE)
?
假设“矩形内的部分没有内容颜色”意味着您希望矩形内有不同的填充;您需要在矩形内绘制一个矩形,然后使用笔画宽度 0 和所需的填充颜色。
例如:
绘图视图.java
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;
public class DrawView extends View {
Paint paint = new Paint();
public DrawView(Context context) {
super(context);
}
@Override
public void onDraw(Canvas canvas) {
paint.setColor(Color.BLACK);
paint.setStrokeWidth(3);
canvas.drawRect(30, 30, 80, 80, paint);
paint.setStrokeWidth(0);
paint.setColor(Color.CYAN);
canvas.drawRect(33, 60, 77, 77, paint );
paint.setColor(Color.YELLOW);
canvas.drawRect(33, 33, 77, 60, paint );
}
}
启动它的活动:
开始绘图.java
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
public class StartDraw extends Activity {
DrawView drawView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
drawView = new DrawView(this);
drawView.setBackgroundColor(Color.WHITE);
setContentView(drawView);
}
}
...会变成这样:
https://i.stack.imgur.com/J1z1o.png
//white background
canvas.drawRGB(255, 255, 255);
//border's properties
paint.setColor(Color.BLACK);
paint.setStrokeWidth(0);
paint.setStyle(Paint.Style.STROKE);
canvas.drawRect(100, 100, 200, 200, paint);
创建一个新类MyView, Which extends View
。覆盖 onDraw(Canvas canvas)
方法以在 Canvas
上绘制矩形。
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.View;
public class MyView extends View {
Paint paint;
Path path;
public MyView(Context context) {
super(context);
init();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MyView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init(){
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(10);
paint.setStyle(Paint.Style.STROKE);
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
canvas.drawRect(30, 50, 200, 350, paint);
canvas.drawRect(100, 100, 300, 400, paint);
//drawRect(left, top, right, bottom, paint)
}
}
然后使用我们的自定义视图 MyView.Call 将您的 Java 活动移动到 setContentView()
。
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
}
有关更多详细信息,您可以访问这里
http://developer.android.com/reference/android/graphics/Canvas.html
paint.setStrokeWidth(3);
paint.setColor(BLACK);
并且您的 drawRect
之一应该可以工作。
代码很好,只需将油漆的样式设置为 STROKE
paint.setStyle(Paint.Style.STROKE);
不知道这是否为时已晚,但我解决这个问题的方法是绘制四个细长的矩形,它们共同构成一个大边框。用一个矩形绘制边框似乎是不可撤销的,因为它们都是不透明的,因此您应该分别绘制边框的每个边缘。