Android(安卓)手势
16lz
2022-05-15
本文参考文献：《疯狂Android讲义 : 第2版 》
使用 Android 手势监测需要两个步骤：
- 实现 GestureDetector.OnGestureListener 监听器实例以创建 GestureDetector 对象；
- 为组件的 TouchEvent 事件绑定监听器，在事件处理中把组件上的 TouchEvent 事件交给 GestureDetector 处理，而 GestureDetector 就会检测是否触发了特定的手势动作。
下面是测试不同动作触发哪种手势的实例：
package com.toby.personal.testlistview;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.GestureDetector;import android.view.MotionEvent;import android.widget.Toast;public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener { final private static String TAG = "Toby_Test"; private GestureDetector detector; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 必须创建手势检测器 detector = new GestureDetector(this, this); } @Override public boolean onTouchEvent(MotionEvent event) { // 注意此处的处理 return detector.onTouchEvent(event); } @Override public boolean onDown(MotionEvent e) { Toast.makeText(this, "onDown", Toast.LENGTH_SHORT).show(); return false; } @Override public void onShowPress(MotionEvent e) { Toast.makeText(this, "onShowPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onSingleTapUp(MotionEvent e) { Toast.makeText(this, "onSingleTapUp", Toast.LENGTH_SHORT).show(); return false; } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { Toast.makeText(this, "onScroll", Toast.LENGTH_SHORT).show(); return false; } @Override public void onLongPress(MotionEvent e) { Toast.makeText(this, "onLongPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { Toast.makeText(this, "onFling", Toast.LENGTH_SHORT).show(); return false; }}通过 Fling 手势缩放图片
主布局文件的内容：
<?xml version="1.0" encoding="utf-8"?> 主程序的内容如下：
package com.toby.personal.testlistview;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Matrix;import android.graphics.drawable.BitmapDrawable;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.GestureDetector;import android.view.MotionEvent;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener { final private static String TAG = "Toby_Test"; private GestureDetector detector; private ImageView imageView; private Bitmap bitmap; private int width; private int height; private float currentScale = 1; private Matrix matrix; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 必须创建手势检测器 detector = new GestureDetector(this, this); imageView = (ImageView) findViewById(R.id.image); matrix = new Matrix(); bitmap = BitmapFactory.decodeResource(this.getResources(), R.drawable.girl04); width = bitmap.getWidth(); height = bitmap.getHeight(); imageView.setImageBitmap( BitmapFactory.decodeResource(this.getResources(), R.drawable.girl04)); } @Override public boolean onTouchEvent(MotionEvent event) { // 注意此处的处理 return detector.onTouchEvent(event); } @Override public boolean onDown(MotionEvent e) {// Toast.makeText(this, "onDown", Toast.LENGTH_SHORT).show(); return false; } @Override public void onShowPress(MotionEvent e) {// Toast.makeText(this, "onShowPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onSingleTapUp(MotionEvent e) {// Toast.makeText(this, "onSingleTapUp", Toast.LENGTH_SHORT).show(); return false; } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {// Toast.makeText(this, "onScroll", Toast.LENGTH_SHORT).show(); return false; } @Override public void onLongPress(MotionEvent e) {// Toast.makeText(this, "onLongPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { Toast.makeText(this, "onFling", Toast.LENGTH_SHORT).show(); velocityX = Math.max(Math.min(velocityX, 4000), -4000); currentScale += currentScale * velocityX / 4000.0f; currentScale = Math.max(currentScale, 0.01f); matrix.reset(); matrix.setScale(currentScale, currentScale, 160, 200); BitmapDrawable tmp = (BitmapDrawable) imageView.getDrawable(); if (!tmp.getBitmap().isRecycled()) { // 如果图片还未回收，先强制回收该图片 tmp.getBitmap().recycle(); } Bitmap bitmap2 = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); imageView.setImageBitmap(bitmap2); return true; }}通过手势实现翻页效果
主布局文件的代码如下：
<?xml version="1.0" encoding="utf-8"?> 主程序文件的内容如下：
package com.toby.personal.testlistview;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;import android.view.animation.Animation;import android.view.animation.AnimationUtils;import android.widget.ImageView;import android.widget.Toast;import android.widget.ViewFlipper;public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener { final private static String TAG = "Toby_Test"; private ViewFlipper flipper; private GestureDetector detector; Animation[] animations = new Animation[4]; final int FLIP_DISTANCE = 50; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 必须创建手势检测器 detector = new GestureDetector(this, this); flipper = (ViewFlipper) findViewById(R.id.flipper); flipper.addView(addImageView(R.drawable.girl01)); flipper.addView(addImageView(R.drawable.girl02)); flipper.addView(addImageView(R.drawable.girl03)); flipper.addView(addImageView(R.drawable.girl04)); flipper.addView(addImageView(R.drawable.girl05)); animations[0] = AnimationUtils.loadAnimation(this, R.anim.slide_in_right); animations[1] = AnimationUtils.loadAnimation(this, R.anim.slide_out_left); } private View addImageView(int resId) { ImageView imageView = new ImageView(this); imageView.setImageResource(resId); imageView.setScaleType(ImageView.ScaleType.CENTER); return imageView; } @Override public boolean onTouchEvent(MotionEvent event) { // 注意此处的处理 return detector.onTouchEvent(event); } @Override public boolean onDown(MotionEvent e) {// Toast.makeText(this, "onDown", Toast.LENGTH_SHORT).show(); return false; } @Override public void onShowPress(MotionEvent e) {// Toast.makeText(this, "onShowPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onSingleTapUp(MotionEvent e) {// Toast.makeText(this, "onSingleTapUp", Toast.LENGTH_SHORT).show(); return false; } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {// Toast.makeText(this, "onScroll", Toast.LENGTH_SHORT).show(); return false; } @Override public void onLongPress(MotionEvent e) {// Toast.makeText(this, "onLongPress", Toast.LENGTH_SHORT).show(); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { Toast.makeText(this, "onFling", Toast.LENGTH_SHORT).show(); if (e1.getX() - e2.getX() > FLIP_DISTANCE) { flipper.setInAnimation(animations[0]); flipper.setOutAnimation(animations[1]); flipper.showPrevious(); return true; } if (e2.getX() - e1.getX() > FLIP_DISTANCE){ flipper.setInAnimation(this, android.R.anim.slide_in_left); flipper.setOutAnimation(this, android.R.anim.slide_out_right); flipper.showNext(); return true; } return false; }}更多相关文章
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