單指觸控拖曳1個textView物件：使用onTouchEvent方法


注意：整個事件程式碼都必須放在
onCreate() 
{  
}
下面
..........................

範例：


import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.TextView;
import android.widget.AbsoluteLayout.LayoutParams;
import android.widget.*;
import android.view.*;



private float touchX;
private float touchY;
private int   tvWidth  = LayoutParams.WRAP_CONTENT;
private int   tvHeight = LayoutParams.WRAP_CONTENT;
private TextView tv = null;


protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
// 取得 TextView 物件
tv = (TextView)findViewById(R.id.textView1);
}




// 利用 MotionEvent 處理觸控程序
public boolean onTouchEvent(MotionEvent event) {
     
    touchX = event.getX();       // 觸控的 X 軸位置
    touchY = event.getY() - 50;  // 觸控的 Y 軸位置
     
        // 判斷觸控動作
    switch( event.getAction() ) {
      
            case MotionEvent.ACTION_DOWN:  // 按下
                 tv.setLayoutParams(new AbsoluteLayout.LayoutParams( tvWidth, tvHeight, (int)touchX, (int)touchY));
                break;
                
            case MotionEvent.ACTION_MOVE:  // 拖曳移動
                  tv.setLayoutParams( new AbsoluteLayout.LayoutParams( tvWidth, tvHeight, (int)touchX, (int)touchY));
                break;
                
            case MotionEvent.ACTION_UP:  // 放開
   
                break;
        }
     
        
    return super.onTouchEvent(event);
        
 }//end of onTouchEvent()