自定义视图显示在屏幕
的中心我写了一个自定义的视图类。自定义视图显示在屏幕
我已经实现在主要布局在XML中的自定义视图。并使用以下代码设置屏幕中心的参数
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/cs_background"
android:id="@+id/layout"
>
<com.drawings.DrawingView
android:id="@+id/drawingview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
/>
</RelativeLayout>
在图形布局中,它在中心位置上正确显示。但是当我在模拟器上执行时,它显示在左上角。
我试图改变以编程方式实现布局,使用下面的代码。
RelativeLayout layout = new RelativeLayout(this);
DrawingView myView = new DrawingView(this);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.CENTER_IN_PARENT, RelativeLayout.TRUE);
layout.addView(myView,params);
setContentView(linearLayout);
但仍是它在左上角的核心人。
我drawingview类,
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class DrawingView extends View
{
Context context;
private Path mPath;
private Bitmap backgound;
private Paint mPaint;
private float mX,mY;
private static final float TOUCH_TOLERANCE =4;
public DrawingView(Context c)
{
super(c);
context = c;
init();
}
public DrawingView (Context c, AttributeSet as)
{
super(c,as);
context = c;
init();
}
private void init()
{
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
backgound = BitmapFactory.decodeResource(context.getResources(), R.drawable.cs_one);
}
@Override
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(backgound, 0, 0, null);
if(!mPath.isEmpty())
canvas.drawPath(mPath, mPaint);
invalidate();
}
private void touch_start(float x, float y)
{
mPath.moveTo(x, y);
}
private void touch_move(float x, float y)
{
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE)
{
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
}
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
break;
case MotionEvent.ACTION_UP:
// touch_up();
break;
}
invalidate();
return true;
}
}
是什么问题?以及如何在屏幕中心显示自定义视图。 ?
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
this.setMeasuredDimension(backgound.getWidth(), backgound.getHeight());
}
实现onMeasure(INT,INT)
改变它
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT);
到
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT);
我试着实现代码但没用。仍然只在左边的核心展示。 – Ram
你应该在你的自定义视图类来实现
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
在这里面,你应该计算的高度和宽度自定义视图。 如果您需要在父布局*您的自定义视图 - 确保:
- 自定义视图高度=父视图高度
AND/OR
- 自定义视图宽度! !=父视图宽度
例如:
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final int height = mCircleRadius * 2; //calculated
final int width = getMeasuredWidth(); //parent width
setMeasuredDimension(width, height);
}
现在你可以使用旁边的自定义视图:
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
附:你看到android:layout_centerHorizontal="true"
不起作用。原因是在onMeasure代替的计算精确宽度使用父宽度。
我尝试执行代码但没用。仍然只在左边的核心展示 – Ram
与DrawingView发布您的代码。 –
post DrawingView – Akhil
@changweiyao我已经添加了绘图视图类 – RVG