Question

我是Android开发的新手。我有一个扩展View的类DrawView，它就像一个简单的绘图应用程序

public class DrawView extends View implements OnTouchListener {

    Bitmap bitmap;
    Canvas bitmapCanvas;
    int color;

    // Position of finger down
    float pX, pY;

    // Position of finger up
    float mX, mY;

    // Create new path
    Path path = new Path();

    // Is view initialized?!
    boolean isInitialized;

    // Create new paint
    Paint paint = new Paint();

    int begX, begY, endX, endY = 0;         


    //DrawView constructor
    public DrawView(Context context) {
            // Initialize new view
            super(context);
            setFocusable(false);
            setFocusableInTouchMode(false);
            this.setOnTouchListener(this);
            requestLayout();

            paint.setAntiAlias(true);
            paint.setStyle(Style.STROKE);

            // There is no bitmap yet
            isInitialized = false;
    }

    //Initialize bitmap and canvas
    private void init() {

            bitmap = Bitmap.createBitmap(getWidth(), getHeight()/2, Bitmap.Config.RGB_565);
            bitmap.setPixel(72, 72, Color.BLACK);

            // Create new canvas and set bitmap
            bitmapCanvas = new Canvas();
            bitmapCanvas.setBitmap(bitmap);

            // ... set canvas background color
            bitmapCanvas.drawColor(Color.WHITE);

            // We're done with initialization
            isInitialized = true;
    }

    //Reset canvas
    public void reset(){
            bitmapCanvas.drawColor(Color.WHITE);  
    }

    //Handle event 'onDraw'
    @Override
    public void onDraw(Canvas canvas) {

            // Check if initialized
            if (!isInitialized)
                    init();

            // Draw bitmap!
            canvas.drawBitmap(bitmap, 0, 0, paint);
    }

    //Handle event 'onTouch'        
    public boolean onTouch(View view, MotionEvent event) {
            // Check event type

            switch (event.getAction()) {

            // Finger down
            case MotionEvent.ACTION_DOWN:

                    paint.setColor(Color.BLACK);
                    paint.setStrokeWidth(7f);
                    paint.setStrokeJoin(Paint.Join.ROUND);
                    paint.setStrokeCap(Paint.Cap.ROUND);
                    paint.setAntiAlias(true);

                    // Get current position
                    pX = event.getX();
                    pY = event.getY();                      

                    // Set beginning of path to (posX,posY)                     
                    path.moveTo(pX, pY);
                    begX= (int) pX;
                    begY = (int) pY;
                    bitmapCanvas.drawPoint(pX, pY, paint);

                    break;

            // Finger moves
            case MotionEvent.ACTION_MOVE:
                    mX = event.getX();
                    mY = event.getY();

                    // Set position of end of path
                    path.lineTo(mX, mY);
                    endX = (int) mX;
                    endY = (int) mY;

                    // Draw path
                    bitmapCanvas.drawPath(path, paint);

                    // Invalidate canvas (redraw the view)

                    invalidate();
                    break;

            // Finger up
            case MotionEvent.ACTION_UP:

                    mX = event.getX();
                    mY = event.getY();

                    if (mY == pY && mX == pX){                      
                        bitmapCanvas.drawPoint(pX, pY, paint);
                        invalidate();
                    }

                    path.reset(); 
                    break;

            }

            return true;
    }
}

在我的默认布局中，我希望它包含DrawView和其他元素（button，textview ...）

如何将“默认布局”拆分为包含具有这些元素的DrawView？感谢

编辑：我应该在哪里放置此代码以使DrawView正常工作

public class Draw extends Activity {
DrawView drawView;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    drawView = new DrawView(this);
    setContentView(drawView);
    drawView.requestFocus();
}
}

Answer 1

将您的视图的全名添加到您的布局中。例如：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
...>
<TextView.../>
<my.package.MyCustomView

    android:id="@+id/my_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    />
<Button.../>
</LinearLayout>

此处MyCustomView是扩展View的java类的名称，my.package是包含该类的包的名称。您可以看到可以向其添加LayoutParams ，因为我添加了layout_height或layout_width。

修改

如果您想在XML布局中使用自定义视图，则必须至少将此构造函数添加到您的类中：

public MyCustomView(Context context, AttributeSet attrs){ super(context, attrs); ... }

Answer 2

我实际上不知道你想要什么，但你可以根据你的要求使用任何布局这里是你的视图和分屏中的另一个视图的简单布局

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:layout_weight="1">

    <TextView /> <!--your textview-->
    <TextView /> <!--your textview-->
    <TextView /> <!--your textview-->
</LinearLayout>

<com.androidapp.DrawView android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_weight="1"/>

</LinearLayout>

这将为您的视图分割相同大小的屏幕，并使用嵌套LinearLayout

分割另一个视图

如果要显示带有包装尺寸的内容，只需在DrawView顶部显示并在高度上使用wrap_content或在底部显示而不是在0.2或o中给出它们的重量时移除重量。 3，不管是浮动

修改定义两个构造函数

public DrawView(Context context) { // Initialize new view super(context); initObject(); } public MyCustomView(Context context, AttributeSet attrs){ super(context, attrs); initObject(); } private void initObject(){ setFocusable(false); setFocusableInTouchMode(false); this.setOnTouchListener(this); requestLayout(); paint.setAntiAlias(true); paint.setStyle(Style.STROKE); // There is no bitmap yet isInitialized = false; }

将View类添加到默认布局

2 个答案: