Question

我正在尝试更新应用以使用素材设计菜单抽屉。使用this tutorial我的应用程序非常有用，每个片段加载并显示正确的屏幕信息。问题是应用程序的一部分是颜色选择器对话框。我似乎无法找到我发现此对话框的页面了。它从主要活动中运行时运行正常，就像我目前在两个应用程序中执行它一样。这是我使用的颜色选择器：

import android.os.Bundle;
import android.app.Dialog;
import android.content.Context;
import android.graphics.*;
import android.view.MotionEvent;
import android.view.View;

public class ColorPicker extends Dialog {

    public interface OnColorChangedListener {
        void colorChanged(int color);
    }

    private OnColorChangedListener mListener;
    private int mInitialColor;

    private static class ColorPickerView extends View {
        private Paint mPaint;
        private Paint mCenterPaint;
        private final int[] mColors;
        private OnColorChangedListener mListener;

        ColorPickerView(Context c, OnColorChangedListener l, int color) {
            super(c);
            mListener = l;
            mColors = new int[] {
                    0xFFFF0000, 0xFFFF00FF, 0xFF0000FF, 0xFF00FFFF, 0xFF00FF00,
                    0xFFFFFF00, 0xFFFF0000
            };
            Shader s = new SweepGradient(0, 0, mColors, null);

            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mPaint.setShader(s);
            mPaint.setStyle(Paint.Style.STROKE);
            //sets the size of the outer ring
            mPaint.setStrokeWidth(60);
            //mPaint.setStrokeWidth(32); original value

            mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mCenterPaint.setColor(color);
            mCenterPaint.setStrokeWidth(5);
        }

        private boolean mTrackingCenter;
        private boolean mHighlightCenter;

        @Override
        protected void onDraw(Canvas canvas) {
            float r = CENTER_X - mPaint.getStrokeWidth()*0.5f;

            canvas.translate(CENTER_X, CENTER_X);

            canvas.drawOval(new RectF(-r, -r, r, r), mPaint);
            canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint);

            if (mTrackingCenter) {
                int c = mCenterPaint.getColor();
                mCenterPaint.setStyle(Paint.Style.STROKE);

                if (mHighlightCenter) {
                    mCenterPaint.setAlpha(0xFF);
                } else {
                    mCenterPaint.setAlpha(0x80);
                }
                canvas.drawCircle(0, 0, CENTER_RADIUS + mCenterPaint.getStrokeWidth(), mCenterPaint);

                mCenterPaint.setStyle(Paint.Style.FILL);
                mCenterPaint.setColor(c);
            }
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(CENTER_X*2, CENTER_Y*2);
        }
        //changes the size of the color picker
        private static final int CENTER_X = 300;
        private static final int CENTER_Y = 300;
        private static final int CENTER_RADIUS = 200;

        private int ave(int s, int d, float p) {
            return s + java.lang.Math.round(p * (d - s));
        }

        private int interpColor(int colors[], float unit) {
            if (unit <= 0) {
                return colors[0];
            }
            if (unit >= 1) {
                return colors[colors.length - 1];
            }

            float p = unit * (colors.length - 1);
            int i = (int)p;
            p -= i;

            int c0 = colors[i];
            int c1 = colors[i+1];
            int a = ave(Color.alpha(c0), Color.alpha(c1), p);
            int r = ave(Color.red(c0), Color.red(c1), p);
            int g = ave(Color.green(c0), Color.green(c1), p);
            int b = ave(Color.blue(c0), Color.blue(c1), p);

            return Color.argb(a, r, g, b);
        }

        private static final float PI = 3.1415926f;

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX() - CENTER_X;
            float y = event.getY() - CENTER_Y;
            boolean inCenter = java.lang.Math.sqrt(x*x + y*y) <= CENTER_RADIUS;

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    mTrackingCenter = inCenter;
                    if (inCenter) {
                        mHighlightCenter = true;
                        invalidate();
                        break;
                    }
                case MotionEvent.ACTION_MOVE:
                    if (mTrackingCenter) {
                        if (mHighlightCenter != inCenter) {
                            mHighlightCenter = inCenter;
                            invalidate();
                        }
                    } else {
                        float angle = (float)java.lang.Math.atan2(y, x);
                        float unit = angle/(2*PI);
                        if (unit < 0) {
                            unit += 1;
                        }
                        mCenterPaint.setColor(interpColor(mColors, unit));
                        invalidate();
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    if (mTrackingCenter) {
                        if (inCenter) {
                            mListener.colorChanged(mCenterPaint.getColor());
                        }
                        mTrackingCenter = false;
                        invalidate();
                    }
                    break;
            }
            return true;
        }
    }

这是我一直看到的错误：

Process: com.comsofinteractive.tipcalculator, PID: 29536
    android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
            at android.view.ViewRootImpl.setView(ViewRootImpl.java:743)
            at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:298)
            at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:87)
            at android.app.Dialog.show(Dialog.java:313)
            at com.comsofinteractive.tipcalculator.activity.MessagesFragment.onClick(MessagesFragment.java:110)
            at android.view.View.performClick(View.java:5254)
            at android.view.View$PerformClick.run(View.java:21179)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:145)
            at android.app.ActivityThread.main(ActivityThread.java:6843)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)

以下是第109和110行，110是根据上述日志问题所在 - 假设我读得正确。这些是onclick事件。

ColorPicker font = new ColorPicker( getActivity().getApplication(), this, Color.WHITE);
font.show();

我已经阅读了一些关于使用片段和对话框的帖子，其中一些来自其他论坛，没有给出的答案似乎解决了我的问题。任何帮助指出答案的方向将不胜感激。

Answer 1

ApplicationContext不应用于创建对话框等任务。当您处于片段中时，您只需通过调用片段getActivity()方法即可获得活动上下文。

实际上，我遇到了同样的问题。

替换以下行：

ColorPicker font = new ColorPicker( getActivity().getApplication(), this, Color.WHITE);

。通过

ColorPicker font = new ColorPicker( getActivity(), this, Color.WHITE);

使用颜色选择器对话框与片段

1 个答案: