Spinner与Adapter

来源：互联网发布：淘宝css模板编辑：程序博客网时间：2024/04/27 18:41

Francis学习笔记四

--------------------------------Spinner与Adapter

1.下拉选择控件Spinner;

2.事件监听;

一、关系说明图：

二、控件spinner学习

附部分源码：

<span style="font-size:24px;">package myapplication.com.myapplication3;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.CheckBox;import android.widget.CompoundButton;import android.widget.RadioGroup;import android.widget.Spinner;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    String[] cities = {"成都", "重庆", "武汉", "深圳"};    ArrayAdapter<String> adapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);</span>

<span style="font-size:24px;">        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, cities);        Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);        spinner1.setAdapter(adapter);        spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {            @Override            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {<span></span>//方法一：如下</span>

<span style="font-size:24px;">//                if(position == 0)//                    display("第一个被选中了");//                else if(position == 1)//                    display("第二个被选中了");</span>

<span style="font-size:24px;"><span></span>//方法二：直接显示TextView,如果上面的View对象是多个组成，则不用方法二（如下）                display(((TextView)view).getText().toString());            }            @Override            public void onNothingSelected(AdapterView<?> parent) {            }        });    }    private void display(String dp) {        Toast.makeText(this, dp, Toast.LENGTH_SHORT).show();    }}</span>

说明：

1)注意ArrayAdapter中第二个参数 resource，上面用的是android.layout.simple_spinner_item.

<span style="font-size:32px;"> ArrayAdapter(Context context, @LayoutRes int resource, @NonNull T[] objects)</span>

2)setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){

public void onItemSelected(AdapterView<?> parent, View view, int position, long id ){

}

});

0 0