事件 和 手勢
事件處理 :
- 物理事件處理
- 觸摸屏事件處理
- 手勢
物理事件處理:
- 基於監聽事件處理
- 基於回調事件處理
基於回調的時間處理: 重寫Activity 回調方法
OnTouchEvent + OnKeyDown + OnKeyUp
基於回調處理事件,採用通用性事件 比如在物理按鍵
1.物理事件 提供三個事件 :
按下 : OnkeyDown, OnKeyUp: ONKeyLongPress(): 長按鍵
Android 當中位每個物理按鍵提供關鍵字常量: keyCODE_MENU,KEYCODE_HOME
案例: 連續按兩次返回鍵返回地圖
package com.example.myapplication;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
/**
* 功能: 連續按兩次返回鍵 退出當前應用
*/
public class MainActivity extends AppCompatActivity {
private long exitTime = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
// 執行退出方法,
exit();
return true;
}
return super.onKeyDown(keyCode, event);
}
public void exit() {
if( (System.currentTimeMillis() - exitTime ) > 2000){
Toast.makeText(MainActivity.this, "再按一次退出程序", Toast.LENGTH_SHORT).show();
exitTime = System.currentTimeMillis();
}else{
finish();
System.exit(0);
}
}
}
觸摸事件
OnTouchEvent ()
package com.example.myapplication;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.RelativeLayout;
import androidx.appcompat.app.AppCompatActivity;
/**
* 功能: 通過Touch 移動帽子 給企鵝帶帽子
* 1. s實例自頂HatView 在圖中 顯示帽子位置
* 2. 通過監聽OnTouchEvent 不斷更新 X,Y 座標
* 3. 將帽子佈局管理器中,動態天劍
*/
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 添加帽子對象,觸摸事件監聽器
final HatView hatView = new HatView(MainActivity.this);
hatView.setOnTouchListener(new View.OnTouchListener(){
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
hatView.bitmapX = motionEvent.getX()- 80; // 減去帽子一般高度,中心點移動
hatView.bitmapY = motionEvent.getY();
// 衝新繪製
hatView.invalidate();
return true;
}
});
RelativeLayout relativeLayout = findViewById(R.id.relativeLayout);
relativeLayout.addView(hatView);
}
}
package com.example.myapplication;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;
/**
* Hat Postition 通過Touch 方式 移動
* */
public class HatView extends View {
public float bitmapX;
public float bitmapY;
public HatView(Context context) {
super(context);
this.bitmapX = 0.0f;
this.bitmapY = 0.0f;
}
/**
* 重新繪製帽子
* */
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint = new Paint();
Bitmap bitmap = BitmapFactory.decodeResource(this.getResources(), R.drawable.hat);
canvas.drawBitmap(bitmap,bitmapX,bitmapY,paint);
if(bitmap.isRecycled()){
bitmap.recycle();
}
}
}
手勢檢測
1.Android 爲手勢檢測提供一個 GestureDetector.onGestureListener
手勢監聽器 必須重寫其六個方法,onDown,OnFling(用戶手指在觸摸屏拖過觸發),OnLongPress
OnScroll,onShowPress,onSingleTapUp(用戶手指在屏幕上親敲擊觸發)
實例用戶的觸發功能:
package com.example.myapplication;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.ViewFlipper;
import androidx.appcompat.app.AppCompatActivity;
/**
* 手勢方式滑動動畫
*/
public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener {
ViewFlipper flipper; //定義ViewFlipper
GestureDetector detector; //定義手勢檢測器
Animation[] animation = new Animation[4];//定義動畫數組,爲ViewFlipper指定切換動畫
final int distance = 50; //定義手勢動作兩點之間最小距離
//定義圖片數組
private int[] images = new int[]{R.drawable.img01, R.drawable.img02, R.drawable.img03,
R.drawable.img04,
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
detector = new GestureDetector(MainActivity.this, this);
// 將顯示的動畫加入ViewFlipper 當中,並且初始化動畫數組
flipper = findViewById(R.id.flipper);
for(int i= 0; i< images.length; i++){
ImageView imageView = new ImageView(this);
imageView.setImageResource(images[i]);
flipper.addView(imageView);
}
// 加載動畫資源組件
animation[0] = AnimationUtils.loadAnimation(this, R.anim.slide_in_left);
animation[1] = AnimationUtils.loadAnimation(this, R.anim.slide_out_left);
animation[2] = AnimationUtils.loadAnimation(this, R.anim.slide_in_right);
animation[3] = AnimationUtils.loadAnimation(this, R.anim.slide_out_right);
}
@Override
public boolean onDown(MotionEvent motionEvent) {
return false;
}
@Override
public void onShowPress(MotionEvent motionEvent) {
}
@Override
public boolean onSingleTapUp(MotionEvent motionEvent) {
return false;
}
@Override
public boolean onScroll(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
return false;
}
@Override
public void onLongPress(MotionEvent motionEvent) {
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float v, float v1) {
// 通過觸摸座標的 判斷滑動趨勢
if ((e1.getX() - e2.getX()) > distance){
flipper.setInAnimation(animation[2]);
flipper.setAnimation(animation[1]);
flipper.showPrevious();
return true;
}else if (e2.getX() - e1.getX() > distance) {
//爲flipper設置切換的動畫
flipper.setInAnimation(animation[0]);
flipper.setOutAnimation(animation[3]);
flipper.showNext();
return true;
}
return false;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
return detector.onTouchEvent(event);
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<ViewFlipper
android:id = "@+id/flipper"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ViewFlipper>
</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:fromXDelta="-100%p"
android:toXDelta="0"
android:duration="500"/>
</set>
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:duration="500"
android:fromXDelta="100%p"
android:toXDelta="0"/>
</set>
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:duration="500"
android:fromXDelta="0"
android:toXDelta="-100%p"/>
</set>
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:duration="500"
android:fromXDelta="0"
android:toXDelta="100%p"/>
</set>
- 手勢添加
自定義的手勢:
Getsures Builder 手勢應用APP
總結: 1. GestureLibararias 加載 自定義的 手勢庫
2. 獲取GestureOverlayView 設置其事件監聽器
3. 從GestureOverlayView 所有的手勢預測只,得到裏面最大值 打分
4. 從edito編輯框原來的值,與判斷打分最高值手勢相加 會寫到原來的編輯框中
package com.example.myapplication;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.Prediction;
import android.graphics.Color;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.EditText;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;
/**
* 手勢方式滑動動畫
*/
public class MainActivity extends AppCompatActivity implements GestureOverlayView.OnGesturePerformedListener {
private GestureDetector detector;
private GestureLibrary librarry;
private EditText editText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 加載自定義手勢文件, 不成功退出
librarry = GestureLibraries.fromRawResource(MainActivity.this, R.raw.gestures);
editText = findViewById(R.id.editText);
if(!librarry.load()){
finish();
}
// 獲取GestureOverlayView 設置其事件監聽器
GestureOverlayView gestureOverlayView = findViewById(R.id.gesture);
gestureOverlayView.setGestureColor(Color.BLACK);
gestureOverlayView.setFadeOffset(1000);
gestureOverlayView.addOnGesturePerformedListener(MainActivity.this);
}
@Override
public void onGesturePerformed(GestureOverlayView gestureOverlayView, Gesture gesture) {
// 獲取其最佳匹配,並更新編輯欄
ArrayList<Prediction> predictions = librarry.recognize(gesture);
int index = 0;// 保存當前預測的索引號
double score = 0.0;// 保存當前預測的得分
for (int i = 0; i < predictions.size(); i++) {// 獲得最佳匹配結果
Prediction result = predictions.get(i);// 獲得一個預測結果
if (result.score > score) {
index = i;
score = result.score;
}
}
String Text = editText.getText().toString();
Text += predictions.get(index).name;
editText.setText(Text);
}
}
<?xml version="1.0" encoding="utf-8"?>
<EditText
android:id="@+id/editText"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_marginLeft="40dp"
android:layout_marginTop="190dp" />
<android.gesture.GestureOverlayView
android:id="@+id/gesture"
android:layout_width="320dp"
android:layout_height="180dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="85dp"
android:gestureStrokeType="multiple" />