本文实例讲述了Android编程之控件可拖动的实现方法。分享给大家供大家参考，具体如下：
点击和触摸的区别是什么?
点击: 一组动作的集合 手指按下着按钮 手指要在按钮停留一段时间 手指离开按钮
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private static final String TAG = "DragViewActivity";
private ImageView iv_dv_view;
private TextView tv_drag_view;
private int startx;
private int starty;
private SharedPreferences sp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.dragview);
// Drawable drawable = new ColorDrawable(color.transparent);
// getWindow().setBackgroundDrawable(drawable);
iv_dv_view = (ImageView) this.findViewById(R.id.iv_dv_view);
tv_drag_view = (TextView) this.findViewById(R.id.tv_drag_view);
sp = this.getSharedPreferences("config", Context.MODE_PRIVATE);
iv_dv_view.setOnTouchListener(this);
}
@Override
protected void onResume() {
super.onResume();
int x = sp.getInt("lastx", 0);
int y = sp.getInt("lasty", 0);
// iv_dv_view.layout(iv_dv_view.getLeft() + x, iv_dv_view.getTop() + y,
// iv_dv_view.getRight() + x, iv_dv_view.getBottom() + y);
// iv_dv_view.invalidate();//界面重新渲染
LayoutParams params = (LayoutParams) iv_dv_view.getLayoutParams();
params.leftMargin = x;
params.topMargin = y;
iv_dv_view.setLayoutParams(params);
}
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (v.getId()) {
// 如果手指放在imageView上拖动
case R.id.iv_dv_view:
// event.getRawX(); //获取手指第一次接触屏幕在x方向的坐标
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:// 获取手指第一次接触屏幕
startx = (int) event.getRawX();
starty = (int) event.getRawY();
break;
case MotionEvent.ACTION_MOVE:// 手指在屏幕上移动对应的事件
int x = (int) event.getRawX();
int y = (int) event.getRawY();
if (y < 400) {
// 设置TextView在窗体的下面
tv_drag_view.layout(tv_drag_view.getLeft(), 420,
tv_drag_view.getRight(), 440);
} else {
tv_drag_view.layout(tv_drag_view.getLeft(), 60,
tv_drag_view.getRight(), 80);
}
// 获取手指移动的距离
int dx = x - startx;
int dy = y - starty;
// 得到imageView最开始的各顶点的坐标
int l = iv_dv_view.getLeft();
int r = iv_dv_view.getRight();
int t = iv_dv_view.getTop();
int b = iv_dv_view.getBottom();
// 更改imageView在窗体的位置
iv_dv_view.layout(l + dx, t + dy, r + dx, b + dy);
// 获取移动后的位置
startx = (int) event.getRawX();
starty = (int) event.getRawY();
break;
case MotionEvent.ACTION_UP:// 手指离开屏幕对应事件
Log.i(TAG, "手指离开屏幕");
// 记录最后图片在窗体的位置
int lasty = iv_dv_view.getTop();
int lastx = iv_dv_view.getLeft();
Editor editor = sp.edit();
editor.putInt("lasty", lasty);
editor.putInt("lastx", lastx);
editor.commit();
break;
}
break;
}
return true;// 不会中断触摸事件的返回
}
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xml如下：
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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#cc000000"
>
<ImageView
android:layout_width="160dip"
android:layout_height="60dip"
android:background="@drawable/button_background_selected"
android:id="@+id/iv_dv_view"
/>
<TextView
android:id="@+id/tv_drag_view"
android:layout_marginTop="80dip"
android:layout_width="fill_parent"
android:layout_height="20dip"
android:text="按住绿色条拖动归属地显示的位置"
/>
</RelativeLayout>
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触摸: 手指一挨着屏幕 手指移动 手指离开屏幕
希望本文所述对大家Android程序设计有所帮助。