title: React-native ListView keys
body: <p>I'm getting a warning on my app that bothers me. the react keeps saying that I need to add key for each row, but no matter what I cannot add these keys.</p>
  
  <p>my code looks like this:</p>
  
  <pre><code> &lt;ListView
     style={styles.listView}
     dataSource={this.state.favs}
     renderSeparator={() =&gt; &lt;View style={styles.listSeparator}/&gt;}
     renderRow={(rowData,i) =&gt; &lt;Card data={rowData} 
              onPress={this.onCardPress.bind(this,rowData)} /&gt; }
  /&gt;
  </code></pre>
  
  <p>I try to add the key on my component like this <code>&lt;Card key={rowData.id}/&gt;/</code>
   and I also tried to get the key from the props inside my component and add it in the first element of the component on my case is a TouchbleOpacity</p>
  
  <pre><code>&lt;TouchableWithoutFeedback
          key={this.props.key}
          style={styles.cardBtn}&gt;
  </code></pre>
  
  <p>Someone could hive me a hint? or should I should ignore this warning?</p>