将值从 activity 传递到视图 class

Question

我有一个 activity，其中有 3 个不同视图的复选框。这些复选框用于选择颜色。

在 DrawingView class 中，我必须使用选中的颜色在我的 canvas 上绘图。我想要的是将整数值从 activity 传递到视图 class 并相应地设置油漆颜色。我尝试使用 getter 和 setter，但我得到的是黑色。我想这是因为颜色是在构造函数本身中设置的，并且当我选中任何框时它都不会改变。

请参考this以下代码的更新

代码：

MainActivity：这里选择了color/checkbox。而绘图是在这个activity本身的布局中完成的。

        carImageView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent motionEvent) {
            drawingView=new DrawingView(carImageView.getContext());
            drawingView=new DrawingView(carImageView.getContext(),null);
            drawingView.setColor(color);
            return false;
        }
    });


  scratchesCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
      @Override
      public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
          if(b)
          {
              color=1;
              chipsCb.setChecked(false);
              dentsCb.setChecked(false);
          }
      }
  });
    chipsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
            if(b)
            {
                color=2;
                scratchesCb.setChecked(false);
                dentsCb.setChecked(false);
            }
        }
    });
    dentsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
            if(b)
            {
                color=3;
                chipsCb.setChecked(false);
                scratchesCb.setChecked(false);
            }
        }
    });
}

查看Class:

   public DrawingView(Context context, @Nullable AttributeSet attrs) {
   super(context, attrs);
    mPaint=new Paint();
    if(color==1)
        mPaint.setColor(Color.RED);
    else if(color==2)
        mPaint.setColor(Color.BLUE);
    else if(color==3)
        mPaint.setColor(Color.GREEN);
    this.context=context;
    mPath=new Path();
    mPaint.setAntiAlias(true);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.MITER);
    mPaint.setStrokeWidth(5f);
}
     public void setColor(int color){
    this.color=color;
}
public int getColor(){
    return this.color;
}

编辑

我不一定要使用完全相同的代码。我想要的只是在选中复选框以能够在图像视图上绘制时更改油漆颜色。欢迎任何其他方法。

Answer 1

您需要在 View 上调用 invalidate() 以使其更新。

试试这个，

final DrawingView drawingView = new DrawingView(carImageView.getContext());

carImageView.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent motionEvent) {
        drawingView.setColor(color);
        return false;
    }
});


scratchesCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
  @Override
  public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
      if(b)
      {
          color = 1;
          drawingView.setColor(color);

          chipsCb.setChecked(false);
          dentsCb.setChecked(false);
      }
  }
});

chipsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
        if(b)
        {
            color = 2;
            drawingView.setColor(color);

            scratchesCb.setChecked(false);
            dentsCb.setChecked(false);
        }
    }
});


dentsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
        if(b)
        {
            color = 3;
            drawingView.setColor(color);

            chipsCb.setChecked(false);
            scratchesCb.setChecked(false);
        }
    }
});

DrawingView.java

public DrawingView(Context context) {
    super(context);
    this.context = context;
    init();
}

public DrawingView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    this.context=context;
    init();
}

private void init() {
    mPath=new Path();

    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.MITER);
    mPaint.setStrokeWidth(5f);
    setColor(color);
}


public void setColor(int color){
    this.color=color;
    if(color==1)
        mPaint.setColor(Color.RED);
    else if(color==2)
        mPaint.setColor(Color.BLUE);
    else if(color==3)
        mPaint.setColor(Color.GREEN);

    // Call invalidate
    invalidate();
}

Answer 2

您需要更改函数 setColor。

1.change mPaint 颜色。

2.add invalidate() 重绘视图。

public void setColor(int color){
    this.color=color;
     mPaint.setColor(color);
    invalidate();
}

Answer 3

在 MainActivity 中，您正在创建一个与显示的图像视图无关的 DrawingView。因此，当您更改颜色时，您并没有更改显示的图像视图的颜色，而是未连接的 DrawingView 的颜色。图像视图从未定义过新颜色，并且始终默认为黑色。

这是一个基于您最近提供的代码的小型工作应用程序的视频。单击新复选框时，也许所有颜色都不应更改，但您将能够单独解决该问题。

我对 Java 代码所做的更改被这样评论。还对 XML 进行了更改，以允许您的代码在我的环境中运行，但这些更改未被评论。

MainActivity.java（更新）

public class MainActivity extends AppCompatActivity {
    ImageView caricon;
    int itemSelected = 0;
    private DrawingView carImageView;
    Bitmap bitmap;
    ImageView backarrow;
    TextView nextcheckinAB2;
    Bitmap bmp;
    public static int color;
    CheckBox scratchesCb, chipsCb, dentsCb;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        carImageView = (DrawingView) findViewById(R.id.carImageView);
        scratchesCb = (CheckBox) findViewById(R.id.scratchesCheckBox);
        chipsCb = (CheckBox) findViewById(R.id.ChipCheckbx);
        dentsCb = (CheckBox) findViewById(R.id.DentsCheckBox);

        // Change: Make sure to initialize the color
        color = 1;
        carImageView.setColor(color);

        carImageView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                // drawingView = new DrawingView(carImageView.getContext(),null);
                carImageView.setColor(color);
                return false;
            }
        });


        scratchesCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (b) {
                    color = 1;
                    carImageView.clearCanvas();
                    carImageView.setColor(1); //
                    chipsCb.setChecked(false);
                    dentsCb.setChecked(false);
                }
            }
        });
        chipsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (b) {
                    color = 2;
                    carImageView.setColor(2);
                    scratchesCb.setChecked(false);
                    dentsCb.setChecked(false);

                }
            }
        });
        dentsCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (b) {
                    color = 3;
                    // Change: Do like the other check boxes althogh not really needed.
                    carImageView.setColor(3);
                    chipsCb.setChecked(false);
                    scratchesCb.setChecked(false);

                }
            }
        });
    }
}

DrawingView.java（更新）

public class DrawingView extends android.support.v7.widget.AppCompatImageView {
    private Path mPath;
    private Paint mPaint;
    private float mX, mY;
    private static final float TOLERANCE = 5;
    int color;
    Context context;

    public DrawingView(Context context) {
        super(context);
        this.context = context;
        init();
    }

    public DrawingView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
        init();


    }

    public void init() {
        mPath = new Path();
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.MITER);
        mPaint.setStrokeWidth(5f);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawPath(mPath, mPaint);
    }

    public void setColor(int color) {
        if (color == 1) {
            mPaint.setColor(Color.RED);
            this.color = color;
            invalidate();
        } else if (color == 2) {
            mPaint.setColor(Color.BLUE);
            this.color = color;
            invalidate();
        } else if (color == 3) {
            mPaint.setColor(Color.GREEN);
            this.color = color;
            invalidate();
        }

    }

    public int getColor() {
        return this.color;
    }

    private void onStartTouch(float x, float y) {
        mPath.moveTo(x, y);
        mX = x;
        mY = y;
    }

    private void moveTouch(float x, float y) {
        float dx = Math.abs(x - mX);
        float dy = Math.abs(y - mY);
        if (dx >= TOLERANCE || dy >= TOLERANCE) {
            mPath.quadTo(mX, mY, (mX + x) / 2, (mY + y) / 2);
            mX = x;
            mY = y;
        }
    }

    public void clearCanvas() {
        mPath.reset();
        mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        invalidate();
    }

    private void upTouch() {
        mPath.lineTo(mX, mY);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                onStartTouch(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                moveTouch(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                upTouch();
                invalidate();
                break;
        }

        return true;

    }
}

activity_main.xml（更新）

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"
        android:layout_marginRight="5dp"
        android:orientation="horizontal"
        android:weightSum="3">

        <HorizontalScrollView
            android:id="@+id/horizontalSrollView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1">

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <RelativeLayout
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dp"
                    android:layout_weight="1">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="5dp"

                        android:orientation="vertical">

                        <LinearLayout
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:orientation="horizontal"
                            android:paddingLeft="15dp"
                            android:paddingRight="15dp"
                            android:paddingTop="5dp"
                            android:weightSum="2">

                            <ImageView
                                android:layout_width="20dp"
                                android:layout_height="20dp"
                                android:layout_marginRight="2dp"
                                android:layout_weight="0.5"
                                android:background="@android:color/holo_red_light" />

                            <TextView
                                android:layout_width="wrap_content"
                                android:layout_height="wrap_content"
                                android:layout_marginLeft="2dp"
                                android:layout_weight="1.5"
                                android:text="Scratches"
                                android:textColor="#000" />
                        </LinearLayout>

                        <CheckBox
                            android:id="@+id/scratchesCheckBox"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_gravity="center"
                            android:checked="true" />
                    </LinearLayout>

                </RelativeLayout>

                <RelativeLayout
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="5dp"
                        android:orientation="vertical">

                        <LinearLayout
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:orientation="horizontal"
                            android:paddingLeft="15dp"
                            android:paddingRight="15dp"
                            android:paddingTop="5dp"
                            android:weightSum="2">

                            <ImageView
                                android:layout_width="20dp"
                                android:layout_height="20dp"
                                android:layout_marginRight="2dp"
                                android:layout_weight="0.5"
                                android:background="@android:color/holo_blue_light" />

                            <TextView
                                android:layout_width="wrap_content"
                                android:layout_height="wrap_content"
                                android:layout_marginLeft="2dp"
                                android:layout_weight="1.5"
                                android:text="Chips"
                                android:textColor="#000" />
                        </LinearLayout>

                        <CheckBox
                            android:id="@+id/ChipCheckbx"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_gravity="center" />
                    </LinearLayout>

                </RelativeLayout>

                <RelativeLayout
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="5dp"
                        android:orientation="vertical">

                        <LinearLayout
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:orientation="horizontal"
                            android:paddingLeft="15dp"
                            android:paddingRight="15dp"
                            android:paddingTop="5dp"
                            android:weightSum="2">

                            <ImageView
                                android:layout_width="20dp"
                                android:layout_height="20dp"
                                android:layout_marginRight="2dp"
                                android:layout_weight="0.5"
                                android:background="@android:color/holo_green_light" />

                            <TextView
                                android:layout_width="wrap_content"
                                android:layout_height="wrap_content"
                                android:layout_marginLeft="2dp"
                                android:layout_weight="1.5"
                                android:text="Dings/Dents"
                                android:textColor="#000" />
                        </LinearLayout>

                        <CheckBox
                            android:id="@+id/DentsCheckBox"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_gravity="center" />
                    </LinearLayout>

                </RelativeLayout>
            </LinearLayout>

        </HorizontalScrollView>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="8.7">

        <[your package name].DrawingView
            android:id="@+id/carImageView"
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:src="@mipmap/ic_launcher"
            android:layout_gravity="center_vertical" />
        <!--<ImageView
            android:id="@+id/carImageView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="center_vertical"/>-->
    </LinearLayout>


</LinearLayout>

Answer 4

"even if I pass a static value, say 3 in main activity in drawingview.setColor(int) it gives black. This means the setColor function in Drawingview isn't working. "

这是否意味着它将调用 paint.setColor(3)？

如果是，这当然会使你的颜色变黑。尝试传递 Color.GREEN 而不是

Answer 5

在 DrawingView 中定义静态数据成员

静态整数颜色=1； //默认

然后，从您的 activity 只需调用

DrawingView.color = 一些值；

变量颜色前的静态关键字将确保您的 DrawingView 的所有对象只有一个变量引用 class。

将值从 activity 传递到视图 class

Passing value from activity to view class

android

view

android-imageview

编辑