从主 activity 调用自定义视图.. 打印 onDraw() 中的消息但未呈现自定义视图

Question

我有两个类 - MainActivity.java 和 MainView.java。

当从主 activity.

触摸屏幕时，我正在尝试呈现自定义视图（在 MainView.java 中定义）

我的代码正在做一件时髦的事情。从主页上，当您触摸屏幕时，它不会呈现我在 MainView.java 中指定的自定义视图 - 但仍会打印出我在 onDraw() 方法中输入的消息，这应该意味着 onDraw( ) 正在运行。为什么我的 onDraw() 方法是运行但它的视图不呈现？

此外，我在 MainActivity.java 和 MainView.java 中的 onTouchEvent 似乎同时响应，尽管我看到的视图是唯一的 activity_main.xml.

请帮忙:(

MainActivity.java

package com.example.owner.thesisapp;

import com.example.owner.thesisapp.MainView;
import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.media.AudioManager;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.media.SoundPool;
import android.view.View;
import android.graphics.Canvas;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;


public class MainActivity extends Activity {

private static SoundPool soundPool;
private static HashMap soundPoolMap;
private static int S1 = R.raw.a3v1;
private static int S2 = R.raw.c3v1;
private static int S3 = R.raw.dsharp3v1;
private static int S4 = R.raw.fsharp3v1;
private int soundID;
private boolean isSoundLoaded = false;

public MainView mainView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mainView = (MainView) findViewById(R.id.main_view);
    soundPool = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
    soundPool.setOnLoadCompleteListener(new SoundPool.OnLoadCompleteListener() {
        @Override
        public void onLoadComplete(SoundPool soundPool, int sampleId,
                                   int status) {
            isSoundLoaded = true;
        }
    });
    soundID = soundPool.load(this, R.raw.fsharp3v1, 1);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    int x = (int)event.getX();
    int y = (int)event.getY();
    if (isSoundLoaded) {
        soundPool.play(soundID, 1f, 1f, 1, 0, 1f);
        Log.d("Test", "Played sound");
    }

    mainView.postInvalidate();
    return false;
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
// Keep landscape orientation
public void onConfigurationChanged(Configuration newConfig) {
    // ignore orientation/keyboard change
    super.onConfigurationChanged(newConfig);
}
}

MainView.java

package com.example.owner.thesisapp;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;

/**
 * Created by Owner on 6/1/2015.
 */
public class MainView extends View {

Bitmap stillWave;
int iy = 0;

public MainView(Context context, AttributeSet attributeSet) {
    super(context, attributeSet);
    stillWave = BitmapFactory.decodeResource(getResources(), R.drawable.wave);
    setWillNotDraw(false);
    Log.d("MAINVIEW: Is this ran?", " ");
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    int x = (int)event.getX();
    int y = (int)event.getY();

    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            Log.d("Action DOWN!", " ");
            iy = 0;
            this.invalidate();
        case MotionEvent.ACTION_MOVE:
            Log.d("Action MOVE!", " ");
        case MotionEvent.ACTION_UP:
            Log.d("Action UP!", " ");
    }

    return false;
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    Log.d("MAINVIEW ONDRAW: Is this ran?", " ");

    int width = canvas.getWidth();
    int height = canvas.getHeight();

    //set background
    Rect wBackground = new Rect();
    wBackground.set(0, 0, width, height);
    Paint pBackground = new Paint();
    pBackground.setStyle(Paint.Style.FILL);
    pBackground.setColor(Color.BLACK);
    canvas.drawRect(wBackground, pBackground);

    //Log.d("garo, sero", width + " " + height);

    //set Wave
    Paint pWave = new Paint();
    pWave.setStyle(Paint.Style.FILL_AND_STROKE);
    pWave.setColor(Color.WHITE);
    pWave.setStrokeWidth(10);
    pWave.setStrokeCap(Paint.Cap.ROUND);

    int waveFlucMin = -100;
    int waveFlucMax = 100;

    float[] coords = new float[width * 2];
    for (int ix = 0; ix < width; ix++) {
        int yoffset = waveFlucMin + (int) (Math.random() * ((waveFlucMax - waveFlucMin) + 1));
        coords[2 * ix] = (float) ix;
        coords[2 * ix + 1] = (float) iy + yoffset;
    }
    //Log.d("Coordinates x?", coords[1] + " " + coords[3] + " " + coords[5] + " " + coords[7] + " " + coords[301] + " " + coords[303] + " ");
    //Log.d("Coordinates y?", coords[0] + " " + coords[2] + " " + coords[4] + " " + coords[6] + " " + coords[300] + " " + coords[302] + " ");
    //Log.d("Generating?", "YES, generating forloop   : " + iy);
    //wait a second between each wave generation
    /*
    try {
        Thread.sleep(1);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    */

    drawWave(coords, width, pWave, canvas);

    if (iy < height) {
        iy += 10;
        invalidate();
    } else {
        //do nothing - finish onDraw() call.
    }

}

private void drawWave(float[] coords, int width, Paint pWave, Canvas canvas) {
    canvas.drawPoints(coords, 0, width*2, pWave);
}
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" tools:context=".MainActivity">


<com.example.owner.thesisapp.MainView
    android:id="@+id/main_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<ImageView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#111C64"/>

Answer 1

问题出在你的布局上。由于您使用的是 RelativeLayout，因此您的自定义 View 和 ImagView 都与左上角对齐。在这种情况下，z 顺序将 ImageView 放在自定义 View 的顶部，并且由于它占据了整个屏幕，因此您看不到自定义视图。

从主 activity 调用自定义视图.. 打印 onDraw() 中的消息但未呈现自定义视图

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