拖动android错误 - 缺少指标？

Question

我为Android 3.1构建一个可拖动的图标..但它没有拖动和我的日志猫不断说

02-29 16:23:37.020:E/View(27355):被要求拖动拇指指标但没有查看02-29 16:23:37.030:E/View(27355):被要求绘制拖影但没有视图

我的代码:

package com.s.dragDrop;

import com.s.dragDrop.R;
import android.app.Activity;
import android.content.ClipData;
import android.os.Bundle;
import android.view.View;
import android.view.View.DragShadowBuilder;
import android.view.View.OnLongClickListener;

public class DragDropTestActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.grid);
        View icon = findViewById(R.id.droid);
        icon.setOnLongClickListener(new OnLongClickListener(){
               @Override
               public boolean onLongClick(View v) {
                ClipData data = ClipData.newPlainText("foo","bar");
                DragShadowBuilder shadowBuilder = new DragShadowBuilder();
                v.startDrag(data, shadowBuilder, v, 0);
                return true;
               }
        });
    }
}

谁能解释为什么？我需要做什么？

Answer 1

为了避免出现此错误,您应该使用拖动视图的DragShadowBuilder构造函数,例如:"DragShadowBuilder shadowBuilder = new DragShadowBuilder(icon);" http://developer.android.com/reference/android/view/View.DragShadowBuilder.html