Android:当用户暂停输入时,如何向Google API发送请求？

Question

我正在使用这个应用程序,用户可以在autoCompleteTextView中输入一个位置,它会根据此处描述的Google Places Api建议位置.

但是,如果用户在一段时间内停止输入,我想通过仅发送请求来限制应用程序发送的请求数量.有谁知道如何做到这一点？

Answer 1

类似于这个答案,但略显简洁,没有引入额外的状态.您也不需要阈值检查,因为performFiltering仅在实际需要过滤时调用.

子类AutoCompleteTextView似乎是唯一的方法,因为你不能覆盖/替换TextWatcher添加的AutoCompleteTextView.

public class DelayAutoCompleteTextView extends AutoCompleteTextView {           
    public DelayAutoCompleteTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private final Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            DelayAutoCompleteTextView.super.performFiltering((CharSequence) msg.obj, msg.arg1);
        }
    };

    @Override
    protected void performFiltering(CharSequence text, int keyCode) {
        mHandler.removeMessages(0);
        mHandler.sendMessageDelayed(mHandler.obtainMessage(0, keyCode, 0, text), 750);
    }
}

Answer 2

我已经找到了上述问题的解决方案，效果非常好。我通过以下方式扩展了 AutoCompleteTextView。如果有人知道如何进一步改进此代码，请告诉我。

public class MyAutoCompleteTextView extends AutoCompleteTextView {

// initialization
int threshold;
int delay = 750;
Handler handler = new Handler();
Runnable run;

// constructor
public MyAutoCompleteTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void performFiltering(final CharSequence text, final int keyCode) {
    // get threshold
    threshold = this.getThreshold();

    // perform filter on null to hide dropdown
    doFiltering(null, keyCode);

    // stop execution of previous handler
    handler.removeCallbacks(run);

    // creation of new runnable and prevent filtering of texts which length
    // does not meet threshold
    run = new Runnable() {
        public void run() {
            if (text.length() > threshold) {
                doFiltering(text, keyCode);
            }
        }
    };

    // restart handler
    handler.postDelayed(run, delay);
}

// starts the actual filtering
private void doFiltering(CharSequence text, int keyCode) {
    super.performFiltering(text, keyCode);
}

}