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自定义MediaView控件继承View，实现拖动位置调用功能
重写draw方法和touch方法
package com.example.media;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;public class MediaView extends View {private float startX;private float endX;private float moveStartX;private float moveX;private float offsetX = 0;private float item0Left = 140.0f;private float item0Top = 20.0f;private float item1Left = 10.0f;private float item1Top = 60.0f;private float item2Left = 350.0f;private float item2Top = 60.0f;private Bitmap bitmap;//342private Bitmap bitmapLeftChild;//268private Bitmap bitmapRightChild;//268private float bitmapWidth = 342.0f;private float bitmapHeight = 342.0f;private Matrix matrix = null;private float fScale = 1.0f;private float item0Position = 140.0f;private float item1Position = 10.0f;private float item2Position = 350.0f;private int itemPosition = 0;private Paint mPaint = new Paint();public MediaView(Context context) {super(context);init();}public MediaView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);init();}public MediaView(Context context, @Nullable AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);init();}@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)public MediaView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {super(context, attrs, defStyleAttr, defStyleRes);}public void init() {Log.d("init:", "init view");// 获取显示图片bitmap = BitmapFactory.decodeResource(this.getContext().getResources(), R.drawable.icon_bg);bitmapLeftChild = BitmapFactory.decodeResource(this.getContext().getResources(), R.drawable.icon_child_bg);bitmapRightChild = BitmapFactory.decodeResource(this.getContext().getResources(), R.drawable.icon_child_bg);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);// get paddingint paddingLeft = getPaddingLeft();int paddingRight = getPaddingRight();int paddingTop = getPaddingTop();int paddingBottom = getPaddingBottom();// get view widthint width = getWidth() - paddingLeft - paddingRight;// get view heightint height = getHeight() - paddingTop - paddingBottom;// 绘制View，左上角坐标（0+paddingLeft,0+paddingTop），右下角坐标（width+paddingLeft,height+paddingTop）//canvas.drawRect(0 + paddingLeft,0 + paddingTop,width + paddingLeft,height + paddingTop, mPaint);// layer 123if (offsetX < 0) {switch (itemPosition) {case 0:canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);canvas.drawBitmap(bitmap, item1Left, item1Top,null);canvas.drawBitmap(bitmap, item0Left, item0Top,null);break;case 1:canvas.drawBitmap(bitmap, item0Left, item0Top,null);canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);canvas.drawBitmap(bitmap, item1Left, item1Top,null);break;case 2:canvas.drawBitmap(bitmap, item0Left, item0Top,null);canvas.drawBitmap(bitmap, item1Left, item1Top,null);canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);break;default:break;}} else {switch (itemPosition) {case 0:canvas.drawBitmap(bitmap, item1Left, item1Top,null);canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);canvas.drawBitmap(bitmap, item0Left, item0Top,null);break;case 1:canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);canvas.drawBitmap(bitmap, item0Left, item0Top,null);canvas.drawBitmap(bitmap, item1Left, item1Top,null);break;case 2:canvas.drawBitmap(bitmap, item1Left, item1Top,null);canvas.drawBitmap(bitmap, item0Left, item0Top,null);canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);break;default:break;}}//canvas.drawBitmap(bitmap, item2Left, item2Top + 40.0f,null);//canvas.drawBitmap(bitmap, item1Left, item1Top,null);//canvas.drawBitmap(bitmap, item0Left, item0Top,null);//canvas.drawBitmap(bitmap, new Rect(0,0,342,342), new Rect(50,0,250,200), null);//bitmap = Bitmap.createScaledBitmap(bitmap, 100, 100, true);//canvas.drawBitmap(bitmap, null, new Rect(0, 0, 100, 100), null);//scaleBitmap(bitmap, 0.1f);Log.d("draw:", "draw");}@Overridepublic boolean onTouchEvent(MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:startX = event.getX();moveStartX = startX;Log.d("start x:", Float.toString(startX));break;case MotionEvent.ACTION_UP:endX = event.getX();if (Math.abs(endX - startX) < bitmap.getWidth() / 2) {item0Left = item0Position;item1Left = item1Position;item2Left = item2Position;} else {if (itemPosition == 0) {if (item0Left <= 10.0f) {item0Left = 10.0f;item1Left = 350.0f;item2Left = 140.0f;itemPosition = 2;} else if (item0Left >= 350.0f) {item0Left = 350.0f;item1Left = 140.0f;item2Left = 10.0f;itemPosition = 1;}} else if (itemPosition == 1) {if (item1Left <= 10.0f) {item0Left = 140.0f;item1Left = 10.0f;item2Left = 350.0f;itemPosition = 0;} else if (item1Left >= 350.0f) {item0Left = 10.0f;item1Left = 350.0f;item2Left = 140.0f;itemPosition = 2;}} else if (itemPosition == 2) {if (item2Left <= 10.0f) {item0Left = 350.0f;item1Left = 140.0f;item2Left = 10.0f;itemPosition = 1;} else if (item2Left >= 350.0f) {item0Left = 140.0f;item1Left = 10.0f;item2Left = 350.0f;itemPosition = 0;}}item0Position = item0Left;item1Position = item1Left;item2Position = item2Left;}Log.d("end x:", Float.toString(endX));break;case MotionEvent.ACTION_MOVE:moveX = event.getX();offsetX = moveX - moveStartX;if (offsetX < 0) {if (itemPosition == 0) {item0Left -= Math.abs(offsetX);//item1Left += Math.abs(offsetX);//item2Left -= Math.abs(offsetX);} else if (itemPosition == 1) {item1Left -= Math.abs(offsetX);//item0Left += Math.abs(offsetX);//item2Left += Math.abs(offsetX);} else if (itemPosition == 2) {item2Left -= Math.abs(offsetX);//item0Left += Math.abs(offsetX);//item1Left -= Math.abs(offsetX);} else {Log.d("left move Position:", Integer.toString(itemPosition));}} else if (offsetX > 0) {if (itemPosition == 0) {item0Left += Math.abs(offsetX);//item1Left -= Math.abs(offsetX);//item2Left += Math.abs(offsetX);} else if (itemPosition == 1) {item1Left += Math.abs(offsetX);//item0Left -= Math.abs(offsetX);//item2Left += Math.abs(offsetX);} else if (itemPosition == 2) {item2Left += Math.abs(offsetX);//item0Left += Math.abs(offsetX);//item1Left -= Math.abs(offsetX);} else {Log.d("right move Position:", Integer.toString(itemPosition));}} else {Log.d("offsetX:", Float.toString(offsetX));}Log.d("move:", Float.toString(offsetX));moveStartX = moveX;break;}// reset drawinvalidate();return true;}}
XML中使用
<com.example.media.MediaViewandroid:id="@+id/media_view"android:background="#ff0989"android:layout_width="654dp"android:layout_height="318dp"android:layout_marginLeft="560dp"android:layout_marginRight="66dp"android:layout_marginTop="84dp"android:visibility="gone"app:layout_constraintTop_toTopOf="parent"app:layout_constraintStart_toStartOf="parent"app:layout_constraintEnd_toEndOf="parent"/>MainJava中获取引用
MediaView mMediaView = (MediaView) findViewById(R.id.media_view);
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