android 拖拽图片&拖动浮动按钮到处跑

来自老外： 

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.MotionEvent ;
import android.widget.AbsoluteLayout;
import android.widget.Button;

public class Drag_And_Drop extends Activity {
  /** Called when the activity is first created. */

  @Override
   public void onCreate(Bundle icicle) {
       super.onCreate(icicle);

       MyView tx = new MyView(this);
       tx.setText("Drag Me");
       AbsoluteLayout l = new AbsoluteLayout(this);

       AbsoluteLayout.LayoutParams p = new AbsoluteLayout.LayoutParams(
AbsoluteLayout.LayoutParams.WRAP_CONTENT,
AbsoluteLayout.LayoutParams.WRAP_CONTENT,10,10);
       l.addView(tx,p);
       setContentView(l);
  }
}
class MyView extends Button{

        public MyView(Context c){
           super(c);
        }

        @Override
        public boolean onMotionEvent(MotionEvent event) {
          int action = event.getAction();
          int mCurX = (int)event.getX();
          int mCurY = (int)event.getY();

          if ( action == MotionEvent.ACTION_MOVE ) {
             //this.setText("x: " + mCurX + ",y: " + mCurY );
              AbsoluteLayout.LayoutParams p = new
AbsoluteLayout.LayoutParams(AbsoluteLayout.LayoutParams.WRAP_CONTENT,
AbsoluteLayout.LayoutParams.WRAP_CONTENT,this.mLeft + mCurX,this.mTop +
mCurY);
              this.setLayoutParams (p);

          }
          if ( action == MotionEvent.ACTION_UP ) {
            //this.setText("not moving");

          }
          return true;
        }

        @Override
        public void draw(Canvas canvas) {
          // TODO Auto-generated method stub
          super.draw(canvas);

        }

    }

　　

拖拽图片效果 

方法一： 

import android.app.Activity;  
import android.os.Bundle;  
import android.view.MotionEvent;  
import android.view.View;  
import android.view.View.OnTouchListener;  
import android.widget.ImageView;  
public class DragSample01 extends Activity {  
    ImageView img;  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.drag_sample01);          
        img = (ImageView)findViewById(R.id.img_view);  
          
        img.setOnTouchListener(new OnTouchListener(){             
            private int mx, my;           
            public boolean onTouch(View v, MotionEvent event) {  
                switch(event.getAction()) {               
                case MotionEvent.ACTION_MOVE:  
                    mx = (int)(event.getRawX());  
                    my = (int)(event.getRawY() - 50);  
                      
                    v.layout(mx - img.getWidth()/2, my - img.getHeight()/2, mx + img.getWidth()/2, my + img.getHeight()/2);  
                    break;  
                }  
                return true;  
            }});  
    }  
}  

　　

  

布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button android:id="@+id/btn" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="拖动看看~~" />
</LinearLayout>

　　

方法二： 

 

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;

public class DraftTest extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		final Button btn = (Button) findViewById(R.id.btn);

		btn.setOnTouchListener(new OnTouchListener() {
			int[] temp = new int[] { 0, 0 };

			public boolean onTouch(View v, MotionEvent event) {

				int eventaction = event.getAction();

				int x = (int) event.getRawX();
				int y = (int) event.getRawY();

				switch (eventaction) {

				case MotionEvent.ACTION_DOWN: // touch down so check if the
					temp[0] = (int) event.getX();
					temp[1] = y - v.getTop();
					break;

				case MotionEvent.ACTION_MOVE: // touch drag with the ball
					v.layout(x - temp[0], y - temp[1], x + v.getWidth()
							- temp[0], y - temp[1] + v.getHeight());

//					v.postInvalidate();
					break;

				case MotionEvent.ACTION_UP:
					break;
				}

				return false;
			}

		});

	}
}

　　

另一种： 

 

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;

public class DraftTest extends Activity {
	/** Called when the activity is first created. */

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		DisplayMetrics dm = getResources().getDisplayMetrics();
		final int screenWidth = dm.widthPixels;
		final int screenHeight = dm.heightPixels - 50;

		final Button b = (Button) findViewById(R.id.btn);

		b.setOnTouchListener(new OnTouchListener() {

			int lastX, lastY;

			public boolean onTouch(View v, MotionEvent event) {
				// TODO Auto-generated method stub
				switch (event.getAction()) {
				case MotionEvent.ACTION_DOWN:
					lastX = (int) event.getRawX();
					lastY = (int) event.getRawY();
					break;
				case MotionEvent.ACTION_MOVE:
					int dx = (int) event.getRawX() - lastX;
					int dy = (int) event.getRawY() - lastY;

					int left = v.getLeft() + dx;
					int top = v.getTop() + dy;
					int right = v.getRight() + dx;
					int bottom = v.getBottom() + dy;

					if (left < 0) {
						left = 0;
						right = left + v.getWidth();
					}

					if (right > screenWidth) {
						right = screenWidth;
						left = right - v.getWidth();
					}

					if (top < 0) {
						top = 0;
						bottom = top + v.getHeight();
					}

					if (bottom > screenHeight) {
						bottom = screenHeight;
						top = bottom - v.getHeight();
					}

					v.layout(left, top, right, bottom);

					lastX = (int) event.getRawX();
					lastY = (int) event.getRawY();

					break;
				case MotionEvent.ACTION_UP:
					break;
				}
				return false;
			}
		});
	}
}

　　

再一个，浮动按钮的实现。 
主要功能： 
点击按钮可以进行拖动； 
当点击按钮时按钮会出现于所有按钮的最上方； 

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.text.style.AbsoluteSizeSpan;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.AbsoluteLayout;
import android.widget.Button;

public class HelloWorld2 extends Activity {
    /** Called when the activity is first created. */
	
	AbsoluteLayout mLayoutGroup = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
        
        mLayoutGroup = new AbsoluteLayout(this);
        AbsoluteLayout.LayoutParams layoutParams = new AbsoluteLayout.LayoutParams
        (320, 480, 0, 0);
        
        setContentView(mLayoutGroup, layoutParams);
        
        Button button= new Button(this);
        button.setText("testButton");
        layoutParams = new AbsoluteLayout.LayoutParams(120, 60, 20, 20);
        mLayoutGroup.addView(button, layoutParams);
        button.setOnClickListener(new OnClickListener() {
			
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				//alert();
			}
		});
        button.setOnTouchListener(touchListener);
        
        final Button btButton = new Button(this);
        btButton.setText("测试按钮移动");
        layoutParams = new AbsoluteLayout.LayoutParams(120, 60, 20, 160);
        mLayoutGroup.addView(btButton, layoutParams);
        btButton.setOnTouchListener(touchListener);
    }
    
    OnTouchListener touchListener = new OnTouchListener()
    {
    	int temp[] = new int[]{0, 0};
		public boolean onTouch(View arg0, MotionEvent arg1) {
			// TODO Auto-generated method stub
			int eventAction = arg1.getAction();
			Log.e("testButtonMove", "OnTouchAction:"+eventAction);
			
			int x = (int)arg1.getRawX();
			int y = (int)arg1.getRawY();
			
			switch (eventAction) {
			case MotionEvent.ACTION_DOWN:
				
				temp[0] = (int)arg1.getX();
				temp[1] = (int)(y-arg0.getTop());	
				
				mLayoutGroup.bringChildToFront(arg0);
				arg0.postInvalidate();
				
				break;
			case MotionEvent.ACTION_MOVE:
				
				int left = x - temp[0];
				int top = y - temp[1];
				int right = left + arg0.getWidth();
				int bottom = top + arg0.getHeight();
				
				arg0.layout(left, top, right, bottom);
				arg0.postInvalidate();
				
				break;

			default:
				break;
			}
			
			return false;
		}
    };
    
    void alert()
    {
    	new AlertDialog.Builder(this)
    	.setNeutralButton("OK", new DialogInterface.OnClickListener() {
			
			public void onClick(DialogInterface arg0, int arg1) {
				// TODO Auto-generated method stub
				
			}
		})
		.setTitle("test button")
		.setMessage("test test test!!!")
		.show();
    }
    
    
}