Android JSONObject-如何循环通过一个平面的 JSON 对象来获得每个键和值

{
"key1": "value1",
"key2": "value2",
"key3": "value3"
}

我怎样才能得到每个项目的关键和价值，而不知道关键和价值事先？

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最佳答案

Use the keys() iterator to iterate over all the properties, and call get() for each.

Iterator<String> iter = json.keys();
while (iter.hasNext()) {
String key = iter.next();
try {
Object value = json.get(key);
} catch (JSONException e) {
// Something went wrong!
}
}

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Take a look at the JSONObject reference:

http://www.json.org/javadoc/org/json/JSONObject.html

Without actually using the object, it looks like using either getNames() or keys() which returns an Iterator is the way to go.

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You shold use the keys() or names() method. keys() will give you an iterator containing all the String property names in the object while names() will give you an array of all key String names.

You can get the JSONObject documentation here

http://developer.android.com/reference/org/json/JSONObject.html

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Short version of Franci's answer:

for(Iterator<String> iter = json.keys();iter.hasNext();) {
String key = iter.next();
...
}

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You'll need to use an Iterator to loop through the keys to get their values.

Here's a Kotlin implementation, you will realised that the way I got the string is using optString(), which is expecting a String or a nullable value.

val keys = jsonObject.keys()
while (keys.hasNext()) {
val key = keys.next()
val value = targetJson.optString(key)
}